Update INSTALL regarding binary compatibility

[perl5.git] / pp_sys.c

/*    pp_sys.c
 *
 *    Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
 *    2004, 2005, 2006, 2007, 2008 by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
 * But only a short way ahead its floor and the walls on either side were
 * cloven by a great fissure, out of which the red glare came, now leaping
 * up, now dying down into darkness; and all the while far below there was
 * a rumour and a trouble as of great engines throbbing and labouring.
 *
 *     [p.945 of _The Lord of the Rings_, VI/iii: "Mount Doom"]
 */

/* This file contains system pp ("push/pop") functions that
 * execute the opcodes that make up a perl program. A typical pp function
 * expects to find its arguments on the stack, and usually pushes its
 * results onto the stack, hence the 'pp' terminology. Each OP structure
 * contains a pointer to the relevant pp_foo() function.
 *
 * By 'system', we mean ops which interact with the OS, such as pp_open().
 */

#include "EXTERN.h"
#define PERL_IN_PP_SYS_C
#include "perl.h"
#include "time64.h"
#include "time64.c"

#ifdef I_SHADOW
/* Shadow password support for solaris - pdo@cs.umd.edu
 * Not just Solaris: at least HP-UX, IRIX, Linux.
 * The API is from SysV.
 *
 * There are at least two more shadow interfaces,
 * see the comments in pp_gpwent().
 *
 * --jhi */
#   ifdef __hpux__
/* There is a MAXINT coming from <shadow.h> <- <hpsecurity.h> <- <values.h>
 * and another MAXINT from "perl.h" <- <sys/param.h>. */
#       undef MAXINT
#   endif
#   include <shadow.h>
#endif

#ifdef I_SYS_WAIT
# include <sys/wait.h>
#endif

#ifdef I_SYS_RESOURCE
# include <sys/resource.h>
#endif

#ifdef NETWARE
NETDB_DEFINE_CONTEXT
#endif

#ifdef HAS_SELECT
# ifdef I_SYS_SELECT
#  include <sys/select.h>
# endif
#endif

/* XXX Configure test needed.
   h_errno might not be a simple 'int', especially for multi-threaded
   applications, see "extern int errno in perl.h".  Creating such
   a test requires taking into account the differences between
   compiling multithreaded and singlethreaded ($ccflags et al).
   HOST_NOT_FOUND is typically defined in <netdb.h>.
*/
#if defined(HOST_NOT_FOUND) && !defined(h_errno) && !defined(__CYGWIN__)
extern int h_errno;
#endif

#ifdef HAS_PASSWD
# ifdef I_PWD
#  include <pwd.h>
# else
#  if !defined(VMS)
    struct passwd *getpwnam (char *);
    struct passwd *getpwuid (Uid_t);
#  endif
# endif
# ifdef HAS_GETPWENT
#ifndef getpwent
  struct passwd *getpwent (void);
#elif defined (VMS) && defined (my_getpwent)
  struct passwd *Perl_my_getpwent (pTHX);
#endif
# endif
#endif

#ifdef HAS_GROUP
# ifdef I_GRP
#  include <grp.h>
# else
    struct group *getgrnam (char *);
    struct group *getgrgid (Gid_t);
# endif
# ifdef HAS_GETGRENT
#ifndef getgrent
    struct group *getgrent (void);
#endif
# endif
#endif

#ifdef I_UTIME
#  if defined(_MSC_VER) || defined(__MINGW32__)
#    include <sys/utime.h>
#  else
#    include <utime.h>
#  endif
#endif

#ifdef HAS_CHSIZE
# ifdef my_chsize  /* Probably #defined to Perl_my_chsize in embed.h */
#   undef my_chsize
# endif
# define my_chsize PerlLIO_chsize
#else
# ifdef HAS_TRUNCATE
#   define my_chsize PerlLIO_chsize
# else
I32 my_chsize(int fd, Off_t length);
# endif
#endif

#ifdef HAS_FLOCK
#  define FLOCK flock
#else /* no flock() */

   /* fcntl.h might not have been included, even if it exists, because
      the current Configure only sets I_FCNTL if it's needed to pick up
      the *_OK constants.  Make sure it has been included before testing
      the fcntl() locking constants. */
#  if defined(HAS_FCNTL) && !defined(I_FCNTL)
#    include <fcntl.h>
#  endif

#  if defined(HAS_FCNTL) && defined(FCNTL_CAN_LOCK)
#    define FLOCK fcntl_emulate_flock
#    define FCNTL_EMULATE_FLOCK
#  else /* no flock() or fcntl(F_SETLK,...) */
#    ifdef HAS_LOCKF
#      define FLOCK lockf_emulate_flock
#      define LOCKF_EMULATE_FLOCK
#    endif /* lockf */
#  endif /* no flock() or fcntl(F_SETLK,...) */

#  ifdef FLOCK
     static int FLOCK (int, int);

    /*
     * These are the flock() constants.  Since this sytems doesn't have
     * flock(), the values of the constants are probably not available.
     */
#    ifndef LOCK_SH
#      define LOCK_SH 1
#    endif
#    ifndef LOCK_EX
#      define LOCK_EX 2
#    endif
#    ifndef LOCK_NB
#      define LOCK_NB 4
#    endif
#    ifndef LOCK_UN
#      define LOCK_UN 8
#    endif
#  endif /* emulating flock() */

#endif /* no flock() */

#define ZBTLEN 10
static const char zero_but_true[ZBTLEN + 1] = "0 but true";

#if defined(I_SYS_ACCESS) && !defined(R_OK)
#  include <sys/access.h>
#endif

#if defined(HAS_FCNTL) && defined(F_SETFD) && !defined(FD_CLOEXEC)
#  define FD_CLOEXEC 1		/* NeXT needs this */
#endif

#include "reentr.h"

#ifdef __Lynx__
/* Missing protos on LynxOS */
void sethostent(int);
void endhostent(void);
void setnetent(int);
void endnetent(void);
void setprotoent(int);
void endprotoent(void);
void setservent(int);
void endservent(void);
#endif

#undef PERL_EFF_ACCESS	/* EFFective uid/gid ACCESS */

/* F_OK unused: if stat() cannot find it... */

#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESS) && defined(EFF_ONLY_OK) && !defined(NO_EFF_ONLY_OK)
    /* Digital UNIX (when the EFF_ONLY_OK gets fixed), UnixWare */
#   define PERL_EFF_ACCESS(p,f) (access((p), (f) | EFF_ONLY_OK))
#endif

#if !defined(PERL_EFF_ACCESS) && defined(HAS_EACCESS)
#   ifdef I_SYS_SECURITY
#       include <sys/security.h>
#   endif
#   ifdef ACC_SELF
        /* HP SecureWare */
#       define PERL_EFF_ACCESS(p,f) (eaccess((p), (f), ACC_SELF))
#   else
        /* SCO */
#       define PERL_EFF_ACCESS(p,f) (eaccess((p), (f)))
#   endif
#endif

#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESSX) && defined(ACC_SELF)
    /* AIX */
#   define PERL_EFF_ACCESS(p,f) (accessx((p), (f), ACC_SELF))
#endif


#if !defined(PERL_EFF_ACCESS) && defined(HAS_ACCESS)	\
    && (defined(HAS_SETREUID) || defined(HAS_SETRESUID)		\
	|| defined(HAS_SETREGID) || defined(HAS_SETRESGID))
/* The Hard Way. */
STATIC int
S_emulate_eaccess(pTHX_ const char* path, Mode_t mode)
{
    const Uid_t ruid = getuid();
    const Uid_t euid = geteuid();
    const Gid_t rgid = getgid();
    const Gid_t egid = getegid();
    int res;

#if !defined(HAS_SETREUID) && !defined(HAS_SETRESUID)
    Perl_croak(aTHX_ "switching effective uid is not implemented");
#else
#ifdef HAS_SETREUID
    if (setreuid(euid, ruid))
#else
#ifdef HAS_SETRESUID
    if (setresuid(euid, ruid, (Uid_t)-1))
#endif
#endif
	Perl_croak(aTHX_ "entering effective uid failed");
#endif

#if !defined(HAS_SETREGID) && !defined(HAS_SETRESGID)
    Perl_croak(aTHX_ "switching effective gid is not implemented");
#else
#ifdef HAS_SETREGID
    if (setregid(egid, rgid))
#else
#ifdef HAS_SETRESGID
    if (setresgid(egid, rgid, (Gid_t)-1))
#endif
#endif
	Perl_croak(aTHX_ "entering effective gid failed");
#endif

    res = access(path, mode);

#ifdef HAS_SETREUID
    if (setreuid(ruid, euid))
#else
#ifdef HAS_SETRESUID
    if (setresuid(ruid, euid, (Uid_t)-1))
#endif
#endif
	Perl_croak(aTHX_ "leaving effective uid failed");

#ifdef HAS_SETREGID
    if (setregid(rgid, egid))
#else
#ifdef HAS_SETRESGID
    if (setresgid(rgid, egid, (Gid_t)-1))
#endif
#endif
	Perl_croak(aTHX_ "leaving effective gid failed");

    return res;
}
#   define PERL_EFF_ACCESS(p,f) (S_emulate_eaccess(aTHX_ (p), (f)))
#endif

PP(pp_backtick)
{
    dVAR; dSP; dTARGET;
    PerlIO *fp;
    const char * const tmps = POPpconstx;
    const I32 gimme = GIMME_V;
    const char *mode = "r";

    TAINT_PROPER("``");
    if (PL_op->op_private & OPpOPEN_IN_RAW)
	mode = "rb";
    else if (PL_op->op_private & OPpOPEN_IN_CRLF)
	mode = "rt";
    fp = PerlProc_popen(tmps, mode);
    if (fp) {
        const char * const type = Perl_PerlIO_context_layers(aTHX_ NULL);
	if (type && *type)
	    PerlIO_apply_layers(aTHX_ fp,mode,type);

	if (gimme == G_VOID) {
	    char tmpbuf[256];
	    while (PerlIO_read(fp, tmpbuf, sizeof tmpbuf) > 0)
		NOOP;
	}
	else if (gimme == G_SCALAR) {
	    ENTER_with_name("backtick");
	    SAVESPTR(PL_rs);
	    PL_rs = &PL_sv_undef;
	    sv_setpvs(TARG, "");	/* note that this preserves previous buffer */
	    while (sv_gets(TARG, fp, SvCUR(TARG)) != NULL)
		NOOP;
	    LEAVE_with_name("backtick");
	    XPUSHs(TARG);
	    SvTAINTED_on(TARG);
	}
	else {
	    for (;;) {
		SV * const sv = newSV(79);
		if (sv_gets(sv, fp, 0) == NULL) {
		    SvREFCNT_dec(sv);
		    break;
		}
		mXPUSHs(sv);
		if (SvLEN(sv) - SvCUR(sv) > 20) {
		    SvPV_shrink_to_cur(sv);
		}
		SvTAINTED_on(sv);
	    }
	}
	STATUS_NATIVE_CHILD_SET(PerlProc_pclose(fp));
	TAINT;		/* "I believe that this is not gratuitous!" */
    }
    else {
	STATUS_NATIVE_CHILD_SET(-1);
	if (gimme == G_SCALAR)
	    RETPUSHUNDEF;
    }

    RETURN;
}

PP(pp_glob)
{
    dVAR;
    OP *result;
    tryAMAGICunTARGET(iter, -1);

    /* Note that we only ever get here if File::Glob fails to load
     * without at the same time croaking, for some reason, or if
     * perl was built with PERL_EXTERNAL_GLOB */

    ENTER_with_name("glob");

#ifndef VMS
    if (PL_tainting) {
	/*
	 * The external globbing program may use things we can't control,
	 * so for security reasons we must assume the worst.
	 */
	TAINT;
	taint_proper(PL_no_security, "glob");
    }
#endif /* !VMS */

    SAVESPTR(PL_last_in_gv);	/* We don't want this to be permanent. */
    PL_last_in_gv = MUTABLE_GV(*PL_stack_sp--);

    SAVESPTR(PL_rs);		/* This is not permanent, either. */
    PL_rs = newSVpvs_flags("\000", SVs_TEMP);
#ifndef DOSISH
#ifndef CSH
    *SvPVX(PL_rs) = '\n';
#endif	/* !CSH */
#endif	/* !DOSISH */

    result = do_readline();
    LEAVE_with_name("glob");
    return result;
}

PP(pp_rcatline)
{
    dVAR;
    PL_last_in_gv = cGVOP_gv;
    return do_readline();
}

PP(pp_warn)
{
    dVAR; dSP; dMARK;
    SV *exsv;
    const char *pv;
    STRLEN len;
    if (SP - MARK > 1) {
	dTARGET;
	do_join(TARG, &PL_sv_no, MARK, SP);
	exsv = TARG;
	SP = MARK + 1;
    }
    else if (SP == MARK) {
	exsv = &PL_sv_no;
	EXTEND(SP, 1);
	SP = MARK + 1;
    }
    else {
	exsv = TOPs;
    }

    if (SvROK(exsv) || (pv = SvPV_const(exsv, len), len)) {
	/* well-formed exception supplied */
    }
    else if (SvROK(ERRSV)) {
	exsv = ERRSV;
    }
    else if (SvPOK(ERRSV) && SvCUR(ERRSV)) {
	exsv = sv_mortalcopy(ERRSV);
	sv_catpvs(exsv, "\t...caught");
    }
    else {
	exsv = newSVpvs_flags("Warning: something's wrong", SVs_TEMP);
    }
    warn_sv(exsv);
    RETSETYES;
}

PP(pp_die)
{
    dVAR; dSP; dMARK;
    SV *exsv;
    const char *pv;
    STRLEN len;
#ifdef VMS
    VMSISH_HUSHED  = VMSISH_HUSHED || (PL_op->op_private & OPpHUSH_VMSISH);
#endif
    if (SP - MARK != 1) {
	dTARGET;
	do_join(TARG, &PL_sv_no, MARK, SP);
	exsv = TARG;
	SP = MARK + 1;
    }
    else {
	exsv = TOPs;
    }

    if (SvROK(exsv) || (pv = SvPV_const(exsv, len), len)) {
	/* well-formed exception supplied */
    }
    else if (SvROK(ERRSV)) {
	exsv = ERRSV;
	if (sv_isobject(exsv)) {
	    HV * const stash = SvSTASH(SvRV(exsv));
	    GV * const gv = gv_fetchmethod(stash, "PROPAGATE");
	    if (gv) {
		SV * const file = sv_2mortal(newSVpv(CopFILE(PL_curcop),0));
		SV * const line = sv_2mortal(newSVuv(CopLINE(PL_curcop)));
		EXTEND(SP, 3);
		PUSHMARK(SP);
		PUSHs(exsv);
		PUSHs(file);
		PUSHs(line);
		PUTBACK;
		call_sv(MUTABLE_SV(GvCV(gv)),
			G_SCALAR|G_EVAL|G_KEEPERR);
		exsv = sv_mortalcopy(*PL_stack_sp--);
	    }
	}
    }
    else if (SvPOK(ERRSV) && SvCUR(ERRSV)) {
	exsv = sv_mortalcopy(ERRSV);
	sv_catpvs(exsv, "\t...propagated");
    }
    else {
	exsv = newSVpvs_flags("Died", SVs_TEMP);
    }
    return die_sv(exsv);
}

/* I/O. */

PP(pp_open)
{
    dVAR; dSP;
    dMARK; dORIGMARK;
    dTARGET;
    SV *sv;
    IO *io;
    const char *tmps;
    STRLEN len;
    bool  ok;

    GV * const gv = MUTABLE_GV(*++MARK);

    if (!isGV(gv))
	DIE(aTHX_ PL_no_usym, "filehandle");

    if ((io = GvIOp(gv))) {
	MAGIC *mg;
	IoFLAGS(GvIOp(gv)) &= ~IOf_UNTAINT;

	if (IoDIRP(io))
	    Perl_ck_warner_d(aTHX_ packWARN2(WARN_IO, WARN_DEPRECATED),
			     "Opening dirhandle %s also as a file",
			     GvENAME(gv));

	mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    /* Method's args are same as ours ... */
	    /* ... except handle is replaced by the object */
	    *MARK-- = SvTIED_obj(MUTABLE_SV(io), mg);
	    PUSHMARK(MARK);
	    PUTBACK;
	    ENTER_with_name("call_OPEN");
	    call_method("OPEN", G_SCALAR);
	    LEAVE_with_name("call_OPEN");
	    SPAGAIN;
	    RETURN;
	}
    }

    if (MARK < SP) {
	sv = *++MARK;
    }
    else {
	sv = GvSVn(gv);
    }

    tmps = SvPV_const(sv, len);
    ok = do_openn(gv, tmps, len, FALSE, O_RDONLY, 0, NULL, MARK+1, (SP-MARK));
    SP = ORIGMARK;
    if (ok)
	PUSHi( (I32)PL_forkprocess );
    else if (PL_forkprocess == 0)		/* we are a new child */
	PUSHi(0);
    else
	RETPUSHUNDEF;
    RETURN;
}

/* These are private to this function, which is private to this file.
   Use 0x04 rather than the next available bit, to help the compiler if the
   architecture can generate more efficient instructions.  */
#define MORTALIZE_NOT_NEEDED	0x04
#define TIED_HANDLE_ARGC_SHIFT	3

static OP *
S_tied_handle_method(pTHX_ const char *const methname, SV **sp,
		     IO *const io, MAGIC *const mg, const U32 flags, ...)
{
    U32 argc = flags >> TIED_HANDLE_ARGC_SHIFT;

    PERL_ARGS_ASSERT_TIED_HANDLE_METHOD;

    /* Ensure that our flag bits do not overlap.  */
    assert((MORTALIZE_NOT_NEEDED & G_WANT) == 0);
    assert((G_WANT >> TIED_HANDLE_ARGC_SHIFT) == 0);

    PUSHMARK(sp);
    PUSHs(SvTIED_obj(MUTABLE_SV(io), mg));
    if (argc) {
	const U32 mortalize_not_needed = flags & MORTALIZE_NOT_NEEDED;
	va_list args;
	va_start(args, flags);
	do {
	    SV *const arg = va_arg(args, SV *);
	    if(mortalize_not_needed)
		PUSHs(arg);
	    else
		mPUSHs(arg);
	} while (--argc);
	va_end(args);
    }

    PUTBACK;
    ENTER_with_name("call_tied_handle_method");
    call_method(methname, flags & G_WANT);
    LEAVE_with_name("call_tied_handle_method");
    return NORMAL;
}

#define tied_handle_method(a,b,c,d)		\
    S_tied_handle_method(aTHX_ a,b,c,d,G_SCALAR)
#define tied_handle_method1(a,b,c,d,e)	\
    S_tied_handle_method(aTHX_ a,b,c,d,G_SCALAR | (1 << TIED_HANDLE_ARGC_SHIFT),e)
#define tied_handle_method2(a,b,c,d,e,f)	\
    S_tied_handle_method(aTHX_ a,b,c,d,G_SCALAR | (2 << TIED_HANDLE_ARGC_SHIFT), e,f)

PP(pp_close)
{
    dVAR; dSP;
    GV * const gv = (MAXARG == 0) ? PL_defoutgv : MUTABLE_GV(POPs);

    if (MAXARG == 0)
	EXTEND(SP, 1);

    if (gv) {
	IO * const io = GvIO(gv);
	if (io) {
	    MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	    if (mg) {
		return tied_handle_method("CLOSE", SP, io, mg);
	    }
	}
    }
    PUSHs(boolSV(do_close(gv, TRUE)));
    RETURN;
}

PP(pp_pipe_op)
{
#ifdef HAS_PIPE
    dVAR;
    dSP;
    register IO *rstio;
    register IO *wstio;
    int fd[2];

    GV * const wgv = MUTABLE_GV(POPs);
    GV * const rgv = MUTABLE_GV(POPs);

    if (!rgv || !wgv)
	goto badexit;

    if (!isGV_with_GP(rgv) || !isGV_with_GP(wgv))
	DIE(aTHX_ PL_no_usym, "filehandle");
    rstio = GvIOn(rgv);
    wstio = GvIOn(wgv);

    if (IoIFP(rstio))
	do_close(rgv, FALSE);
    if (IoIFP(wstio))
	do_close(wgv, FALSE);

    if (PerlProc_pipe(fd) < 0)
	goto badexit;

    IoIFP(rstio) = PerlIO_fdopen(fd[0], "r"PIPE_OPEN_MODE);
    IoOFP(wstio) = PerlIO_fdopen(fd[1], "w"PIPE_OPEN_MODE);
    IoOFP(rstio) = IoIFP(rstio);
    IoIFP(wstio) = IoOFP(wstio);
    IoTYPE(rstio) = IoTYPE_RDONLY;
    IoTYPE(wstio) = IoTYPE_WRONLY;

    if (!IoIFP(rstio) || !IoOFP(wstio)) {
	if (IoIFP(rstio))
	    PerlIO_close(IoIFP(rstio));
	else
	    PerlLIO_close(fd[0]);
	if (IoOFP(wstio))
	    PerlIO_close(IoOFP(wstio));
	else
	    PerlLIO_close(fd[1]);
	goto badexit;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd[0],F_SETFD,fd[0] > PL_maxsysfd);	/* ensure close-on-exec */
    fcntl(fd[1],F_SETFD,fd[1] > PL_maxsysfd);	/* ensure close-on-exec */
#endif
    RETPUSHYES;

badexit:
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_func, "pipe");
#endif
}

PP(pp_fileno)
{
    dVAR; dSP; dTARGET;
    GV *gv;
    IO *io;
    PerlIO *fp;
    MAGIC  *mg;

    if (MAXARG < 1)
	RETPUSHUNDEF;
    gv = MUTABLE_GV(POPs);

    if (gv && (io = GvIO(gv))
	&& (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar)))
    {
	return tied_handle_method("FILENO", SP, io, mg);
    }

    if (!gv || !(io = GvIO(gv)) || !(fp = IoIFP(io))) {
	/* Can't do this because people seem to do things like
	   defined(fileno($foo)) to check whether $foo is a valid fh.
	  if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	      report_evil_fh(gv, io, PL_op->op_type);
	    */
	RETPUSHUNDEF;
    }

    PUSHi(PerlIO_fileno(fp));
    RETURN;
}

PP(pp_umask)
{
    dVAR;
    dSP;
#ifdef HAS_UMASK
    dTARGET;
    Mode_t anum;

    if (MAXARG < 1) {
	anum = PerlLIO_umask(022);
	/* setting it to 022 between the two calls to umask avoids
	 * to have a window where the umask is set to 0 -- meaning
	 * that another thread could create world-writeable files. */
	if (anum != 022)
	    (void)PerlLIO_umask(anum);
    }
    else
	anum = PerlLIO_umask(POPi);
    TAINT_PROPER("umask");
    XPUSHi(anum);
#else
    /* Only DIE if trying to restrict permissions on "user" (self).
     * Otherwise it's harmless and more useful to just return undef
     * since 'group' and 'other' concepts probably don't exist here. */
    if (MAXARG >= 1 && (POPi & 0700))
	DIE(aTHX_ "umask not implemented");
    XPUSHs(&PL_sv_undef);
#endif
    RETURN;
}

PP(pp_binmode)
{
    dVAR; dSP;
    GV *gv;
    IO *io;
    PerlIO *fp;
    SV *discp = NULL;

    if (MAXARG < 1)
	RETPUSHUNDEF;
    if (MAXARG > 1) {
	discp = POPs;
    }

    gv = MUTABLE_GV(POPs);

    if (gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    /* This takes advantage of the implementation of the varargs
	       function, which I don't think that the optimiser will be able to
	       figure out. Although, as it's a static function, in theory it
	       could.  */
	    return S_tied_handle_method(aTHX_ "BINMODE", SP, io, mg,
					G_SCALAR|MORTALIZE_NOT_NEEDED
					| (discp
					   ? (1 << TIED_HANDLE_ARGC_SHIFT) : 0),
					discp);
	}
    }

    if (!(io = GvIO(gv)) || !(fp = IoIFP(io))) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	SETERRNO(EBADF,RMS_IFI);
        RETPUSHUNDEF;
    }

    PUTBACK;
    {
	STRLEN len = 0;
	const char *d = NULL;
	int mode;
	if (discp)
	    d = SvPV_const(discp, len);
	mode = mode_from_discipline(d, len);
	if (PerlIO_binmode(aTHX_ fp, IoTYPE(io), mode, d)) {
	    if (IoOFP(io) && IoOFP(io) != IoIFP(io)) {
		if (!PerlIO_binmode(aTHX_ IoOFP(io), IoTYPE(io), mode, d)) {
		    SPAGAIN;
		    RETPUSHUNDEF;
		}
	    }
	    SPAGAIN;
	    RETPUSHYES;
	}
	else {
	    SPAGAIN;
	    RETPUSHUNDEF;
	}
    }
}

PP(pp_tie)
{
    dVAR; dSP; dMARK;
    HV* stash;
    GV *gv = NULL;
    SV *sv;
    const I32 markoff = MARK - PL_stack_base;
    const char *methname;
    int how = PERL_MAGIC_tied;
    U32 items;
    SV *varsv = *++MARK;

    switch(SvTYPE(varsv)) {
	case SVt_PVHV:
	    methname = "TIEHASH";
	    HvEITER_set(MUTABLE_HV(varsv), 0);
	    break;
	case SVt_PVAV:
	    methname = "TIEARRAY";
	    break;
	case SVt_PVGV:
	    if (isGV_with_GP(varsv)) {
		methname = "TIEHANDLE";
		how = PERL_MAGIC_tiedscalar;
		/* For tied filehandles, we apply tiedscalar magic to the IO
		   slot of the GP rather than the GV itself. AMS 20010812 */
		if (!GvIOp(varsv))
		    GvIOp(varsv) = newIO();
		varsv = MUTABLE_SV(GvIOp(varsv));
		break;
	    }
	    /* FALL THROUGH */
	default:
	    methname = "TIESCALAR";
	    how = PERL_MAGIC_tiedscalar;
	    break;
    }
    items = SP - MARK++;
    if (sv_isobject(*MARK)) { /* Calls GET magic. */
	ENTER_with_name("call_TIE");
	PUSHSTACKi(PERLSI_MAGIC);
	PUSHMARK(SP);
	EXTEND(SP,(I32)items);
	while (items--)
	    PUSHs(*MARK++);
	PUTBACK;
	call_method(methname, G_SCALAR);
    }
    else {
	/* Can't use call_method here, else this: fileno FOO; tie @a, "FOO"
	 * will attempt to invoke IO::File::TIEARRAY, with (best case) the
	 * wrong error message, and worse case, supreme action at a distance.
	 * (Sorry obfuscation writers. You're not going to be given this one.)
	 */
	STRLEN len;
	const char *name = SvPV_nomg_const(*MARK, len);
	stash = gv_stashpvn(name, len, 0);
	if (!stash || !(gv = gv_fetchmethod(stash, methname))) {
	    DIE(aTHX_ "Can't locate object method \"%s\" via package \"%"SVf"\"",
		 methname, SVfARG(SvOK(*MARK) ? *MARK : &PL_sv_no));
	}
	ENTER_with_name("call_TIE");
	PUSHSTACKi(PERLSI_MAGIC);
	PUSHMARK(SP);
	EXTEND(SP,(I32)items);
	while (items--)
	    PUSHs(*MARK++);
	PUTBACK;
	call_sv(MUTABLE_SV(GvCV(gv)), G_SCALAR);
    }
    SPAGAIN;

    sv = TOPs;
    POPSTACK;
    if (sv_isobject(sv)) {
	sv_unmagic(varsv, how);
	/* Croak if a self-tie on an aggregate is attempted. */
	if (varsv == SvRV(sv) &&
	    (SvTYPE(varsv) == SVt_PVAV ||
	     SvTYPE(varsv) == SVt_PVHV))
	    Perl_croak(aTHX_
		       "Self-ties of arrays and hashes are not supported");
	sv_magic(varsv, (SvRV(sv) == varsv ? NULL : sv), how, NULL, 0);
    }
    LEAVE_with_name("call_TIE");
    SP = PL_stack_base + markoff;
    PUSHs(sv);
    RETURN;
}

PP(pp_untie)
{
    dVAR; dSP;
    MAGIC *mg;
    SV *sv = POPs;
    const char how = (SvTYPE(sv) == SVt_PVHV || SvTYPE(sv) == SVt_PVAV)
		? PERL_MAGIC_tied : PERL_MAGIC_tiedscalar;

    if (isGV_with_GP(sv) && !(sv = MUTABLE_SV(GvIOp(sv))))
	RETPUSHYES;

    if ((mg = SvTIED_mg(sv, how))) {
	SV * const obj = SvRV(SvTIED_obj(sv, mg));
        if (obj) {
	    GV * const gv = gv_fetchmethod_autoload(SvSTASH(obj), "UNTIE", FALSE);
	    CV *cv;
	    if (gv && isGV(gv) && (cv = GvCV(gv))) {
	       PUSHMARK(SP);
	       PUSHs(SvTIED_obj(MUTABLE_SV(gv), mg));
	       mXPUSHi(SvREFCNT(obj) - 1);
	       PUTBACK;
	       ENTER_with_name("call_UNTIE");
	       call_sv(MUTABLE_SV(cv), G_VOID);
	       LEAVE_with_name("call_UNTIE");
	       SPAGAIN;
            }
	    else if (mg && SvREFCNT(obj) > 1) {
		Perl_ck_warner(aTHX_ packWARN(WARN_UNTIE),
			       "untie attempted while %"UVuf" inner references still exist",
			       (UV)SvREFCNT(obj) - 1 ) ;
	    }
        }
    }
    sv_unmagic(sv, how) ;
    RETPUSHYES;
}

PP(pp_tied)
{
    dVAR;
    dSP;
    const MAGIC *mg;
    SV *sv = POPs;
    const char how = (SvTYPE(sv) == SVt_PVHV || SvTYPE(sv) == SVt_PVAV)
		? PERL_MAGIC_tied : PERL_MAGIC_tiedscalar;

    if (isGV_with_GP(sv) && !(sv = MUTABLE_SV(GvIOp(sv))))
	RETPUSHUNDEF;

    if ((mg = SvTIED_mg(sv, how))) {
	SV *osv = SvTIED_obj(sv, mg);
	if (osv == mg->mg_obj)
	    osv = sv_mortalcopy(osv);
	PUSHs(osv);
	RETURN;
    }
    RETPUSHUNDEF;
}

PP(pp_dbmopen)
{
    dVAR; dSP;
    dPOPPOPssrl;
    HV* stash;
    GV *gv = NULL;

    HV * const hv = MUTABLE_HV(POPs);
    SV * const sv = newSVpvs_flags("AnyDBM_File", SVs_TEMP);
    stash = gv_stashsv(sv, 0);
    if (!stash || !(gv = gv_fetchmethod(stash, "TIEHASH"))) {
	PUTBACK;
	require_pv("AnyDBM_File.pm");
	SPAGAIN;
	if (!stash || !(gv = gv_fetchmethod(stash, "TIEHASH")))
	    DIE(aTHX_ "No dbm on this machine");
    }

    ENTER;
    PUSHMARK(SP);

    EXTEND(SP, 5);
    PUSHs(sv);
    PUSHs(left);
    if (SvIV(right))
	mPUSHu(O_RDWR|O_CREAT);
    else
	mPUSHu(O_RDWR);
    PUSHs(right);
    PUTBACK;
    call_sv(MUTABLE_SV(GvCV(gv)), G_SCALAR);
    SPAGAIN;

    if (!sv_isobject(TOPs)) {
	SP--;
	PUSHMARK(SP);
	PUSHs(sv);
	PUSHs(left);
	mPUSHu(O_RDONLY);
	PUSHs(right);
	PUTBACK;
	call_sv(MUTABLE_SV(GvCV(gv)), G_SCALAR);
	SPAGAIN;
    }

    if (sv_isobject(TOPs)) {
	sv_unmagic(MUTABLE_SV(hv), PERL_MAGIC_tied);
	sv_magic(MUTABLE_SV(hv), TOPs, PERL_MAGIC_tied, NULL, 0);
    }
    LEAVE;
    RETURN;
}

PP(pp_sselect)
{
#ifdef HAS_SELECT
    dVAR; dSP; dTARGET;
    register I32 i;
    register I32 j;
    register char *s;
    register SV *sv;
    NV value;
    I32 maxlen = 0;
    I32 nfound;
    struct timeval timebuf;
    struct timeval *tbuf = &timebuf;
    I32 growsize;
    char *fd_sets[4];
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
	I32 masksize;
	I32 offset;
	I32 k;

#   if BYTEORDER & 0xf0000
#	define ORDERBYTE (0x88888888 - BYTEORDER)
#   else
#	define ORDERBYTE (0x4444 - BYTEORDER)
#   endif

#endif

    SP -= 4;
    for (i = 1; i <= 3; i++) {
	SV * const sv = SP[i];
	if (!SvOK(sv))
	    continue;
	if (SvREADONLY(sv)) {
	    if (SvIsCOW(sv))
		sv_force_normal_flags(sv, 0);
	    if (SvREADONLY(sv) && !(SvPOK(sv) && SvCUR(sv) == 0))
		Perl_croak_no_modify(aTHX);
	}
	if (!SvPOK(sv)) {
	    Perl_ck_warner(aTHX_ packWARN(WARN_MISC), "Non-string passed as bitmask");
	    SvPV_force_nolen(sv);	/* force string conversion */
	}
	j = SvCUR(sv);
	if (maxlen < j)
	    maxlen = j;
    }

/* little endians can use vecs directly */
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
#  ifdef NFDBITS

#    ifndef NBBY
#     define NBBY 8
#    endif

    masksize = NFDBITS / NBBY;
#  else
    masksize = sizeof(long);	/* documented int, everyone seems to use long */
#  endif
    Zero(&fd_sets[0], 4, char*);
#endif

#  if SELECT_MIN_BITS == 1
    growsize = sizeof(fd_set);
#  else
#   if defined(__GLIBC__) && defined(__FD_SETSIZE)
#      undef SELECT_MIN_BITS
#      define SELECT_MIN_BITS __FD_SETSIZE
#   endif
    /* If SELECT_MIN_BITS is greater than one we most probably will want
     * to align the sizes with SELECT_MIN_BITS/8 because for example
     * in many little-endian (Intel, Alpha) systems (Linux, OS/2, Digital
     * UNIX, Solaris, NeXT, Darwin) the smallest quantum select() operates
     * on (sets/tests/clears bits) is 32 bits.  */
    growsize = maxlen + (SELECT_MIN_BITS/8 - (maxlen % (SELECT_MIN_BITS/8)));
#  endif

    sv = SP[4];
    if (SvOK(sv)) {
	value = SvNV(sv);
	if (value < 0.0)
	    value = 0.0;
	timebuf.tv_sec = (long)value;
	value -= (NV)timebuf.tv_sec;
	timebuf.tv_usec = (long)(value * 1000000.0);
    }
    else
	tbuf = NULL;

    for (i = 1; i <= 3; i++) {
	sv = SP[i];
	if (!SvOK(sv) || SvCUR(sv) == 0) {
	    fd_sets[i] = 0;
	    continue;
	}
	assert(SvPOK(sv));
	j = SvLEN(sv);
	if (j < growsize) {
	    Sv_Grow(sv, growsize);
	}
	j = SvCUR(sv);
	s = SvPVX(sv) + j;
	while (++j <= growsize) {
	    *s++ = '\0';
	}

#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
	s = SvPVX(sv);
	Newx(fd_sets[i], growsize, char);
	for (offset = 0; offset < growsize; offset += masksize) {
	    for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
		fd_sets[i][j+offset] = s[(k % masksize) + offset];
	}
#else
	fd_sets[i] = SvPVX(sv);
#endif
    }

#ifdef PERL_IRIX5_SELECT_TIMEVAL_VOID_CAST
    /* Can't make just the (void*) conditional because that would be
     * cpp #if within cpp macro, and not all compilers like that. */
    nfound = PerlSock_select(
	maxlen * 8,
	(Select_fd_set_t) fd_sets[1],
	(Select_fd_set_t) fd_sets[2],
	(Select_fd_set_t) fd_sets[3],
	(void*) tbuf); /* Workaround for compiler bug. */
#else
    nfound = PerlSock_select(
	maxlen * 8,
	(Select_fd_set_t) fd_sets[1],
	(Select_fd_set_t) fd_sets[2],
	(Select_fd_set_t) fd_sets[3],
	tbuf);
#endif
    for (i = 1; i <= 3; i++) {
	if (fd_sets[i]) {
	    sv = SP[i];
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
	    s = SvPVX(sv);
	    for (offset = 0; offset < growsize; offset += masksize) {
		for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
		    s[(k % masksize) + offset] = fd_sets[i][j+offset];
	    }
	    Safefree(fd_sets[i]);
#endif
	    SvSETMAGIC(sv);
	}
    }

    PUSHi(nfound);
    if (GIMME == G_ARRAY && tbuf) {
	value = (NV)(timebuf.tv_sec) +
		(NV)(timebuf.tv_usec) / 1000000.0;
	mPUSHn(value);
    }
    RETURN;
#else
    DIE(aTHX_ "select not implemented");
#endif
}

/*
=for apidoc setdefout

Sets PL_defoutgv, the default file handle for output, to the passed in
typeglob. As PL_defoutgv "owns" a reference on its typeglob, the reference
count of the passed in typeglob is increased by one, and the reference count
of the typeglob that PL_defoutgv points to is decreased by one.

=cut
*/

void
Perl_setdefout(pTHX_ GV *gv)
{
    dVAR;
    SvREFCNT_inc_simple_void(gv);
    SvREFCNT_dec(PL_defoutgv);
    PL_defoutgv = gv;
}

PP(pp_select)
{
    dVAR; dSP; dTARGET;
    HV *hv;
    GV * const newdefout = (PL_op->op_private > 0) ? (MUTABLE_GV(POPs)) : NULL;
    GV * egv = GvEGVx(PL_defoutgv);

    if (!egv)
	egv = PL_defoutgv;
    hv = isGV_with_GP(egv) ? GvSTASH(egv) : NULL;
    if (! hv)
	XPUSHs(&PL_sv_undef);
    else {
	GV * const * const gvp = (GV**)hv_fetch(hv, GvNAME(egv), GvNAMELEN(egv), FALSE);
	if (gvp && *gvp == egv) {
	    gv_efullname4(TARG, PL_defoutgv, NULL, TRUE);
	    XPUSHTARG;
	}
	else {
	    mXPUSHs(newRV(MUTABLE_SV(egv)));
	}
    }

    if (newdefout) {
	if (!GvIO(newdefout))
	    gv_IOadd(newdefout);
	setdefout(newdefout);
    }

    RETURN;
}

PP(pp_getc)
{
    dVAR; dSP; dTARGET;
    IO *io = NULL;
    GV * const gv = (MAXARG==0) ? PL_stdingv : MUTABLE_GV(POPs);

    if (MAXARG == 0)
	EXTEND(SP, 1);

    if (gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    const U32 gimme = GIMME_V;
	    S_tied_handle_method(aTHX_ "GETC", SP, io, mg, gimme);
	    if (gimme == G_SCALAR) {
		SPAGAIN;
		SvSetMagicSV_nosteal(TARG, TOPs);
	    }
	    return NORMAL;
	}
    }
    if (!gv || do_eof(gv)) { /* make sure we have fp with something */
	if ((!io || (!IoIFP(io) && IoTYPE(io) != IoTYPE_WRONLY))
	  && ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	SETERRNO(EBADF,RMS_IFI);
	RETPUSHUNDEF;
    }
    TAINT;
    sv_setpvs(TARG, " ");
    *SvPVX(TARG) = PerlIO_getc(IoIFP(GvIOp(gv))); /* should never be EOF */
    if (PerlIO_isutf8(IoIFP(GvIOp(gv)))) {
	/* Find out how many bytes the char needs */
	Size_t len = UTF8SKIP(SvPVX_const(TARG));
	if (len > 1) {
	    SvGROW(TARG,len+1);
	    len = PerlIO_read(IoIFP(GvIOp(gv)),SvPVX(TARG)+1,len-1);
	    SvCUR_set(TARG,1+len);
	}
	SvUTF8_on(TARG);
    }
    PUSHTARG;
    RETURN;
}

STATIC OP *
S_doform(pTHX_ CV *cv, GV *gv, OP *retop)
{
    dVAR;
    register PERL_CONTEXT *cx;
    const I32 gimme = GIMME_V;

    PERL_ARGS_ASSERT_DOFORM;

    ENTER;
    SAVETMPS;

    PUSHBLOCK(cx, CXt_FORMAT, PL_stack_sp);
    PUSHFORMAT(cx, retop);
    SAVECOMPPAD();
    PAD_SET_CUR_NOSAVE(CvPADLIST(cv), 1);

    setdefout(gv);	    /* locally select filehandle so $% et al work */
    return CvSTART(cv);
}

PP(pp_enterwrite)
{
    dVAR;
    dSP;
    register GV *gv;
    register IO *io;
    GV *fgv;
    CV *cv = NULL;
    SV *tmpsv = NULL;

    if (MAXARG == 0) {
	gv = PL_defoutgv;
	EXTEND(SP, 1);
    }
    else {
	gv = MUTABLE_GV(POPs);
	if (!gv)
	    gv = PL_defoutgv;
    }
    io = GvIO(gv);
    if (!io) {
	RETPUSHNO;
    }
    if (IoFMT_GV(io))
	fgv = IoFMT_GV(io);
    else
	fgv = gv;

    if (!fgv)
	goto not_a_format_reference;

    cv = GvFORM(fgv);
    if (!cv) {
	const char *name;
	tmpsv = sv_newmortal();
	gv_efullname4(tmpsv, fgv, NULL, FALSE);
	name = SvPV_nolen_const(tmpsv);
	if (name && *name)
	    DIE(aTHX_ "Undefined format \"%s\" called", name);

	not_a_format_reference:
	DIE(aTHX_ "Not a format reference");
    }
    if (CvCLONE(cv))
	cv = MUTABLE_CV(sv_2mortal(MUTABLE_SV(cv_clone(cv))));

    IoFLAGS(io) &= ~IOf_DIDTOP;
    return doform(cv,gv,PL_op->op_next);
}

PP(pp_leavewrite)
{
    dVAR; dSP;
    GV * const gv = cxstack[cxstack_ix].blk_format.gv;
    register IO * const io = GvIOp(gv);
    PerlIO *ofp;
    PerlIO *fp;
    SV **newsp;
    I32 gimme;
    register PERL_CONTEXT *cx;

    if (!io || !(ofp = IoOFP(io)))
        goto forget_top;

    DEBUG_f(PerlIO_printf(Perl_debug_log, "left=%ld, todo=%ld\n",
	  (long)IoLINES_LEFT(io), (long)FmLINES(PL_formtarget)));

    if (IoLINES_LEFT(io) < FmLINES(PL_formtarget) &&
	PL_formtarget != PL_toptarget)
    {
	GV *fgv;
	CV *cv;
	if (!IoTOP_GV(io)) {
	    GV *topgv;

	    if (!IoTOP_NAME(io)) {
		SV *topname;
		if (!IoFMT_NAME(io))
		    IoFMT_NAME(io) = savepv(GvNAME(gv));
		topname = sv_2mortal(Perl_newSVpvf(aTHX_ "%s_TOP", GvNAME(gv)));
		topgv = gv_fetchsv(topname, 0, SVt_PVFM);
		if ((topgv && GvFORM(topgv)) ||
		  !gv_fetchpvs("top", GV_NOTQUAL, SVt_PVFM))
		    IoTOP_NAME(io) = savesvpv(topname);
		else
		    IoTOP_NAME(io) = savepvs("top");
	    }
	    topgv = gv_fetchpv(IoTOP_NAME(io), 0, SVt_PVFM);
	    if (!topgv || !GvFORM(topgv)) {
		IoLINES_LEFT(io) = IoPAGE_LEN(io);
		goto forget_top;
	    }
	    IoTOP_GV(io) = topgv;
	}
	if (IoFLAGS(io) & IOf_DIDTOP) {	/* Oh dear.  It still doesn't fit. */
	    I32 lines = IoLINES_LEFT(io);
	    const char *s = SvPVX_const(PL_formtarget);
	    if (lines <= 0)		/* Yow, header didn't even fit!!! */
		goto forget_top;
	    while (lines-- > 0) {
		s = strchr(s, '\n');
		if (!s)
		    break;
		s++;
	    }
	    if (s) {
		const STRLEN save = SvCUR(PL_formtarget);
		SvCUR_set(PL_formtarget, s - SvPVX_const(PL_formtarget));
		do_print(PL_formtarget, ofp);
		SvCUR_set(PL_formtarget, save);
		sv_chop(PL_formtarget, s);
		FmLINES(PL_formtarget) -= IoLINES_LEFT(io);
	    }
	}
	if (IoLINES_LEFT(io) >= 0 && IoPAGE(io) > 0)
	    do_print(PL_formfeed, ofp);
	IoLINES_LEFT(io) = IoPAGE_LEN(io);
	IoPAGE(io)++;
	PL_formtarget = PL_toptarget;
	IoFLAGS(io) |= IOf_DIDTOP;
	fgv = IoTOP_GV(io);
	if (!fgv)
	    DIE(aTHX_ "bad top format reference");
	cv = GvFORM(fgv);
	if (!cv) {
	    SV * const sv = sv_newmortal();
	    const char *name;
	    gv_efullname4(sv, fgv, NULL, FALSE);
	    name = SvPV_nolen_const(sv);
	    if (name && *name)
		DIE(aTHX_ "Undefined top format \"%s\" called", name);
	    else
		DIE(aTHX_ "Undefined top format called");
	}
	if (cv && CvCLONE(cv))
	    cv = MUTABLE_CV(sv_2mortal(MUTABLE_SV(cv_clone(cv))));
	return doform(cv, gv, PL_op);
    }

  forget_top:
    POPBLOCK(cx,PL_curpm);
    POPFORMAT(cx);
    LEAVE;

    fp = IoOFP(io);
    if (!fp) {
	if (ckWARN2(WARN_CLOSED,WARN_IO)) {
	    if (IoIFP(io))
		report_evil_fh(gv, io, OP_phoney_INPUT_ONLY);
	    else if (ckWARN(WARN_CLOSED))
		report_evil_fh(gv, io, PL_op->op_type);
	}
	PUSHs(&PL_sv_no);
    }
    else {
	if ((IoLINES_LEFT(io) -= FmLINES(PL_formtarget)) < 0) {
	    Perl_ck_warner(aTHX_ packWARN(WARN_IO), "page overflow");
	}
	if (!do_print(PL_formtarget, fp))
	    PUSHs(&PL_sv_no);
	else {
	    FmLINES(PL_formtarget) = 0;
	    SvCUR_set(PL_formtarget, 0);
	    *SvEND(PL_formtarget) = '\0';
	    if (IoFLAGS(io) & IOf_FLUSH)
		(void)PerlIO_flush(fp);
	    PUSHs(&PL_sv_yes);
	}
    }
    /* bad_ofp: */
    PL_formtarget = PL_bodytarget;
    PUTBACK;
    PERL_UNUSED_VAR(newsp);
    PERL_UNUSED_VAR(gimme);
    return cx->blk_sub.retop;
}

PP(pp_prtf)
{
    dVAR; dSP; dMARK; dORIGMARK;
    IO *io;
    PerlIO *fp;
    SV *sv;

    GV * const gv
	= (PL_op->op_flags & OPf_STACKED) ? MUTABLE_GV(*++MARK) : PL_defoutgv;

    if (gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    if (MARK == ORIGMARK) {
		MEXTEND(SP, 1);
		++MARK;
		Move(MARK, MARK + 1, (SP - MARK) + 1, SV*);
		++SP;
	    }
	    PUSHMARK(MARK - 1);
	    *MARK = SvTIED_obj(MUTABLE_SV(io), mg);
	    PUTBACK;
	    ENTER;
	    call_method("PRINTF", G_SCALAR);
	    LEAVE;
	    SPAGAIN;
	    MARK = ORIGMARK + 1;
	    *MARK = *SP;
	    SP = MARK;
	    RETURN;
	}
    }

    sv = newSV(0);
    if (!(io = GvIO(gv))) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	SETERRNO(EBADF,RMS_IFI);
	goto just_say_no;
    }
    else if (!(fp = IoOFP(io))) {
	if (ckWARN2(WARN_CLOSED,WARN_IO))  {
	    if (IoIFP(io))
		report_evil_fh(gv, io, OP_phoney_INPUT_ONLY);
	    else if (ckWARN(WARN_CLOSED))
		report_evil_fh(gv, io, PL_op->op_type);
	}
	SETERRNO(EBADF,IoIFP(io)?RMS_FAC:RMS_IFI);
	goto just_say_no;
    }
    else {
	if (SvTAINTED(MARK[1]))
	    TAINT_PROPER("printf");
	do_sprintf(sv, SP - MARK, MARK + 1);
	if (!do_print(sv, fp))
	    goto just_say_no;

	if (IoFLAGS(io) & IOf_FLUSH)
	    if (PerlIO_flush(fp) == EOF)
		goto just_say_no;
    }
    SvREFCNT_dec(sv);
    SP = ORIGMARK;
    PUSHs(&PL_sv_yes);
    RETURN;

  just_say_no:
    SvREFCNT_dec(sv);
    SP = ORIGMARK;
    PUSHs(&PL_sv_undef);
    RETURN;
}

PP(pp_sysopen)
{
    dVAR;
    dSP;
    const int perm = (MAXARG > 3) ? POPi : 0666;
    const int mode = POPi;
    SV * const sv = POPs;
    GV * const gv = MUTABLE_GV(POPs);
    STRLEN len;

    /* Need TIEHANDLE method ? */
    const char * const tmps = SvPV_const(sv, len);
    /* FIXME? do_open should do const  */
    if (do_open(gv, tmps, len, TRUE, mode, perm, NULL)) {
	IoLINES(GvIOp(gv)) = 0;
	PUSHs(&PL_sv_yes);
    }
    else {
	PUSHs(&PL_sv_undef);
    }
    RETURN;
}

PP(pp_sysread)
{
    dVAR; dSP; dMARK; dORIGMARK; dTARGET;
    int offset;
    IO *io;
    char *buffer;
    SSize_t length;
    SSize_t count;
    Sock_size_t bufsize;
    SV *bufsv;
    STRLEN blen;
    int fp_utf8;
    int buffer_utf8;
    SV *read_target;
    Size_t got = 0;
    Size_t wanted;
    bool charstart = FALSE;
    STRLEN charskip = 0;
    STRLEN skip = 0;

    GV * const gv = MUTABLE_GV(*++MARK);
    if ((PL_op->op_type == OP_READ || PL_op->op_type == OP_SYSREAD)
	&& gv && (io = GvIO(gv)) )
    {
	const MAGIC * mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    SV *sv;
	    PUSHMARK(MARK-1);
	    *MARK = SvTIED_obj(MUTABLE_SV(io), mg);
	    ENTER;
	    call_method("READ", G_SCALAR);
	    LEAVE;
	    SPAGAIN;
	    sv = POPs;
	    SP = ORIGMARK;
	    PUSHs(sv);
	    RETURN;
	}
    }

    if (!gv)
	goto say_undef;
    bufsv = *++MARK;
    if (! SvOK(bufsv))
	sv_setpvs(bufsv, "");
    length = SvIVx(*++MARK);
    SETERRNO(0,0);
    if (MARK < SP)
	offset = SvIVx(*++MARK);
    else
	offset = 0;
    io = GvIO(gv);
    if (!io || !IoIFP(io)) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	SETERRNO(EBADF,RMS_IFI);
	goto say_undef;
    }
    if ((fp_utf8 = PerlIO_isutf8(IoIFP(io))) && !IN_BYTES) {
	buffer = SvPVutf8_force(bufsv, blen);
	/* UTF-8 may not have been set if they are all low bytes */
	SvUTF8_on(bufsv);
	buffer_utf8 = 0;
    }
    else {
	buffer = SvPV_force(bufsv, blen);
	buffer_utf8 = !IN_BYTES && SvUTF8(bufsv);
    }
    if (length < 0)
	DIE(aTHX_ "Negative length");
    wanted = length;

    charstart = TRUE;
    charskip  = 0;
    skip = 0;

#ifdef HAS_SOCKET
    if (PL_op->op_type == OP_RECV) {
	char namebuf[MAXPATHLEN];
#if (defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)) || defined(MPE) || defined(__QNXNTO__)
	bufsize = sizeof (struct sockaddr_in);
#else
	bufsize = sizeof namebuf;
#endif
#ifdef OS2	/* At least Warp3+IAK: only the first byte of bufsize set */
	if (bufsize >= 256)
	    bufsize = 255;
#endif
	buffer = SvGROW(bufsv, (STRLEN)(length+1));
	/* 'offset' means 'flags' here */
	count = PerlSock_recvfrom(PerlIO_fileno(IoIFP(io)), buffer, length, offset,
				  (struct sockaddr *)namebuf, &bufsize);
	if (count < 0)
	    RETPUSHUNDEF;
#ifdef EPOC
        /* Bogus return without padding */
	bufsize = sizeof (struct sockaddr_in);
#endif
	SvCUR_set(bufsv, count);
	*SvEND(bufsv) = '\0';
	(void)SvPOK_only(bufsv);
	if (fp_utf8)
	    SvUTF8_on(bufsv);
	SvSETMAGIC(bufsv);
	/* This should not be marked tainted if the fp is marked clean */
	if (!(IoFLAGS(io) & IOf_UNTAINT))
	    SvTAINTED_on(bufsv);
	SP = ORIGMARK;
	sv_setpvn(TARG, namebuf, bufsize);
	PUSHs(TARG);
	RETURN;
    }
#else
    if (PL_op->op_type == OP_RECV)
	DIE(aTHX_ PL_no_sock_func, "recv");
#endif
    if (DO_UTF8(bufsv)) {
	/* offset adjust in characters not bytes */
	blen = sv_len_utf8(bufsv);
    }
    if (offset < 0) {
	if (-offset > (int)blen)
	    DIE(aTHX_ "Offset outside string");
	offset += blen;
    }
    if (DO_UTF8(bufsv)) {
	/* convert offset-as-chars to offset-as-bytes */
	if (offset >= (int)blen)
	    offset += SvCUR(bufsv) - blen;
	else
	    offset = utf8_hop((U8 *)buffer,offset) - (U8 *) buffer;
    }
 more_bytes:
    bufsize = SvCUR(bufsv);
    /* Allocating length + offset + 1 isn't perfect in the case of reading
       bytes from a byte file handle into a UTF8 buffer, but it won't harm us
       unduly.
       (should be 2 * length + offset + 1, or possibly something longer if
       PL_encoding is true) */
    buffer  = SvGROW(bufsv, (STRLEN)(length+offset+1));
    if (offset > 0 && (Sock_size_t)offset > bufsize) { /* Zero any newly allocated space */
    	Zero(buffer+bufsize, offset-bufsize, char);
    }
    buffer = buffer + offset;
    if (!buffer_utf8) {
	read_target = bufsv;
    } else {
	/* Best to read the bytes into a new SV, upgrade that to UTF8, then
	   concatenate it to the current buffer.  */

	/* Truncate the existing buffer to the start of where we will be
	   reading to:  */
	SvCUR_set(bufsv, offset);

	read_target = sv_newmortal();
	SvUPGRADE(read_target, SVt_PV);
	buffer = SvGROW(read_target, (STRLEN)(length + 1));
    }

    if (PL_op->op_type == OP_SYSREAD) {
#ifdef PERL_SOCK_SYSREAD_IS_RECV
	if (IoTYPE(io) == IoTYPE_SOCKET) {
	    count = PerlSock_recv(PerlIO_fileno(IoIFP(io)),
				   buffer, length, 0);
	}
	else
#endif
	{
	    count = PerlLIO_read(PerlIO_fileno(IoIFP(io)),
				  buffer, length);
	}
    }
    else
#ifdef HAS_SOCKET__bad_code_maybe
    if (IoTYPE(io) == IoTYPE_SOCKET) {
	char namebuf[MAXPATHLEN];
#if defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)
	bufsize = sizeof (struct sockaddr_in);
#else
	bufsize = sizeof namebuf;
#endif
	count = PerlSock_recvfrom(PerlIO_fileno(IoIFP(io)), buffer, length, 0,
			  (struct sockaddr *)namebuf, &bufsize);
    }
    else
#endif
    {
	count = PerlIO_read(IoIFP(io), buffer, length);
	/* PerlIO_read() - like fread() returns 0 on both error and EOF */
	if (count == 0 && PerlIO_error(IoIFP(io)))
	    count = -1;
    }
    if (count < 0) {
	if ((IoTYPE(io) == IoTYPE_WRONLY) && ckWARN(WARN_IO))
		report_evil_fh(gv, io, OP_phoney_OUTPUT_ONLY);
	goto say_undef;
    }
    SvCUR_set(read_target, count+(buffer - SvPVX_const(read_target)));
    *SvEND(read_target) = '\0';
    (void)SvPOK_only(read_target);
    if (fp_utf8 && !IN_BYTES) {
	/* Look at utf8 we got back and count the characters */
	const char *bend = buffer + count;
	while (buffer < bend) {
	    if (charstart) {
	        skip = UTF8SKIP(buffer);
		charskip = 0;
	    }
	    if (buffer - charskip + skip > bend) {
		/* partial character - try for rest of it */
		length = skip - (bend-buffer);
		offset = bend - SvPVX_const(bufsv);
		charstart = FALSE;
		charskip += count;
		goto more_bytes;
	    }
	    else {
		got++;
		buffer += skip;
		charstart = TRUE;
		charskip  = 0;
	    }
        }
	/* If we have not 'got' the number of _characters_ we 'wanted' get some more
	   provided amount read (count) was what was requested (length)
	 */
	if (got < wanted && count == length) {
	    length = wanted - got;
	    offset = bend - SvPVX_const(bufsv);
	    goto more_bytes;
	}
	/* return value is character count */
	count = got;
	SvUTF8_on(bufsv);
    }
    else if (buffer_utf8) {
	/* Let svcatsv upgrade the bytes we read in to utf8.
	   The buffer is a mortal so will be freed soon.  */
	sv_catsv_nomg(bufsv, read_target);
    }
    SvSETMAGIC(bufsv);
    /* This should not be marked tainted if the fp is marked clean */
    if (!(IoFLAGS(io) & IOf_UNTAINT))
	SvTAINTED_on(bufsv);
    SP = ORIGMARK;
    PUSHi(count);
    RETURN;

  say_undef:
    SP = ORIGMARK;
    RETPUSHUNDEF;
}

PP(pp_send)
{
    dVAR; dSP; dMARK; dORIGMARK; dTARGET;
    IO *io;
    SV *bufsv;
    const char *buffer;
    SSize_t retval;
    STRLEN blen;
    STRLEN orig_blen_bytes;
    const int op_type = PL_op->op_type;
    bool doing_utf8;
    U8 *tmpbuf = NULL;
    
    GV *const gv = MUTABLE_GV(*++MARK);
    if (PL_op->op_type == OP_SYSWRITE
	&& gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    SV *sv;

	    if (MARK == SP - 1) {
		sv = *SP;
		mXPUSHi(sv_len(sv));
		PUTBACK;
	    }

	    PUSHMARK(ORIGMARK);
	    *(ORIGMARK+1) = SvTIED_obj(MUTABLE_SV(io), mg);
	    ENTER;
	    call_method("WRITE", G_SCALAR);
	    LEAVE;
	    SPAGAIN;
	    sv = POPs;
	    SP = ORIGMARK;
	    PUSHs(sv);
	    RETURN;
	}
    }
    if (!gv)
	goto say_undef;

    bufsv = *++MARK;

    SETERRNO(0,0);
    io = GvIO(gv);
    if (!io || !IoIFP(io) || IoTYPE(io) == IoTYPE_RDONLY) {
	retval = -1;
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
	    if (io && IoIFP(io))
		report_evil_fh(gv, io, OP_phoney_INPUT_ONLY);
	    else
		report_evil_fh(gv, io, PL_op->op_type);
	}
	SETERRNO(EBADF,RMS_IFI);
	goto say_undef;
    }

    /* Do this first to trigger any overloading.  */
    buffer = SvPV_const(bufsv, blen);
    orig_blen_bytes = blen;
    doing_utf8 = DO_UTF8(bufsv);

    if (PerlIO_isutf8(IoIFP(io))) {
	if (!SvUTF8(bufsv)) {
	    /* We don't modify the original scalar.  */
	    tmpbuf = bytes_to_utf8((const U8*) buffer, &blen);
	    buffer = (char *) tmpbuf;
	    doing_utf8 = TRUE;
	}
    }
    else if (doing_utf8) {
	STRLEN tmplen = blen;
	U8 * const result = bytes_from_utf8((const U8*) buffer, &tmplen, &doing_utf8);
	if (!doing_utf8) {
	    tmpbuf = result;
	    buffer = (char *) tmpbuf;
	    blen = tmplen;
	}
	else {
	    assert((char *)result == buffer);
	    Perl_croak(aTHX_ "Wide character in %s", OP_DESC(PL_op));
	}
    }

    if (op_type == OP_SYSWRITE) {
	Size_t length = 0; /* This length is in characters.  */
	STRLEN blen_chars;
	IV offset;

	if (doing_utf8) {
	    if (tmpbuf) {
		/* The SV is bytes, and we've had to upgrade it.  */
		blen_chars = orig_blen_bytes;
	    } else {
		/* The SV really is UTF-8.  */
		if (SvGMAGICAL(bufsv) || SvAMAGIC(bufsv)) {
		    /* Don't call sv_len_utf8 again because it will call magic
		       or overloading a second time, and we might get back a
		       different result.  */
		    blen_chars = utf8_length((U8*)buffer, (U8*)buffer + blen);
		} else {
		    /* It's safe, and it may well be cached.  */
		    blen_chars = sv_len_utf8(bufsv);
		}
	    }
	} else {
	    blen_chars = blen;
	}

	if (MARK >= SP) {
	    length = blen_chars;
	} else {
#if Size_t_size > IVSIZE
	    length = (Size_t)SvNVx(*++MARK);
#else
	    length = (Size_t)SvIVx(*++MARK);
#endif
	    if ((SSize_t)length < 0) {
		Safefree(tmpbuf);
		DIE(aTHX_ "Negative length");
	    }
	}

	if (MARK < SP) {
	    offset = SvIVx(*++MARK);
	    if (offset < 0) {
		if (-offset > (IV)blen_chars) {
		    Safefree(tmpbuf);
		    DIE(aTHX_ "Offset outside string");
		}
		offset += blen_chars;
	    } else if (offset > (IV)blen_chars) {
		Safefree(tmpbuf);
		DIE(aTHX_ "Offset outside string");
	    }
	} else
	    offset = 0;
	if (length > blen_chars - offset)
	    length = blen_chars - offset;
	if (doing_utf8) {
	    /* Here we convert length from characters to bytes.  */
	    if (tmpbuf || SvGMAGICAL(bufsv) || SvAMAGIC(bufsv)) {
		/* Either we had to convert the SV, or the SV is magical, or
		   the SV has overloading, in which case we can't or mustn't
		   or mustn't call it again.  */

		buffer = (const char*)utf8_hop((const U8 *)buffer, offset);
		length = utf8_hop((U8 *)buffer, length) - (U8 *)buffer;
	    } else {
		/* It's a real UTF-8 SV, and it's not going to change under
		   us.  Take advantage of any cache.  */
		I32 start = offset;
		I32 len_I32 = length;

		/* Convert the start and end character positions to bytes.
		   Remember that the second argument to sv_pos_u2b is relative
		   to the first.  */
		sv_pos_u2b(bufsv, &start, &len_I32);

		buffer += start;
		length = len_I32;
	    }
	}
	else {
	    buffer = buffer+offset;
	}
#ifdef PERL_SOCK_SYSWRITE_IS_SEND
	if (IoTYPE(io) == IoTYPE_SOCKET) {
	    retval = PerlSock_send(PerlIO_fileno(IoIFP(io)),
				   buffer, length, 0);
	}
	else
#endif
	{
	    /* See the note at doio.c:do_print about filesize limits. --jhi */
	    retval = PerlLIO_write(PerlIO_fileno(IoIFP(io)),
				   buffer, length);
	}
    }
#ifdef HAS_SOCKET
    else {
	const int flags = SvIVx(*++MARK);
	if (SP > MARK) {
	    STRLEN mlen;
	    char * const sockbuf = SvPVx(*++MARK, mlen);
	    retval = PerlSock_sendto(PerlIO_fileno(IoIFP(io)), buffer, blen,
				     flags, (struct sockaddr *)sockbuf, mlen);
	}
	else {
	    retval
		= PerlSock_send(PerlIO_fileno(IoIFP(io)), buffer, blen, flags);
	}
    }
#else
    else
	DIE(aTHX_ PL_no_sock_func, "send");
#endif

    if (retval < 0)
	goto say_undef;
    SP = ORIGMARK;
    if (doing_utf8)
        retval = utf8_length((U8*)buffer, (U8*)buffer + retval);

    Safefree(tmpbuf);
#if Size_t_size > IVSIZE
    PUSHn(retval);
#else
    PUSHi(retval);
#endif
    RETURN;

  say_undef:
    Safefree(tmpbuf);
    SP = ORIGMARK;
    RETPUSHUNDEF;
}

PP(pp_eof)
{
    dVAR; dSP;
    GV *gv;
    IO *io;
    MAGIC *mg;
    /*
     * in Perl 5.12 and later, the additional parameter is a bitmask:
     * 0 = eof
     * 1 = eof(FH)
     * 2 = eof()  <- ARGV magic
     *
     * I'll rely on the compiler's trace flow analysis to decide whether to
     * actually assign this out here, or punt it into the only block where it is
     * used. Doing it out here is DRY on the condition logic.
     */
    unsigned int which;

    if (MAXARG) {
	gv = PL_last_in_gv = MUTABLE_GV(POPs);	/* eof(FH) */
	which = 1;
    }
    else {
	EXTEND(SP, 1);

	if (PL_op->op_flags & OPf_SPECIAL) {
	    gv = PL_last_in_gv = GvEGVx(PL_argvgv);	/* eof() - ARGV magic */
	    which = 2;
	}
	else {
	    gv = PL_last_in_gv;			/* eof */
	    which = 0;
	}
    }

    if (!gv)
	RETPUSHNO;

    if ((io = GvIO(gv)) && (mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar))) {
	return tied_handle_method1("EOF", SP, io, mg, newSVuv(which));
    }

    if (!MAXARG && (PL_op->op_flags & OPf_SPECIAL)) {	/* eof() */
	if (io && !IoIFP(io)) {
	    if ((IoFLAGS(io) & IOf_START) && av_len(GvAVn(gv)) < 0) {
		IoLINES(io) = 0;
		IoFLAGS(io) &= ~IOf_START;
		do_open(gv, "-", 1, FALSE, O_RDONLY, 0, NULL);
		if (GvSV(gv))
		    sv_setpvs(GvSV(gv), "-");
		else
		    GvSV(gv) = newSVpvs("-");
		SvSETMAGIC(GvSV(gv));
	    }
	    else if (!nextargv(gv))
		RETPUSHYES;
	}
    }

    PUSHs(boolSV(do_eof(gv)));
    RETURN;
}

PP(pp_tell)
{
    dVAR; dSP; dTARGET;
    GV *gv;
    IO *io;

    if (MAXARG != 0)
	PL_last_in_gv = MUTABLE_GV(POPs);
    else
	EXTEND(SP, 1);
    gv = PL_last_in_gv;

    if (gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
	    return tied_handle_method("TELL", SP, io, mg);
	}
    }
    else if (!gv) {
	if (!errno)
	    SETERRNO(EBADF,RMS_IFI);
	PUSHi(-1);
	RETURN;
    }

#if LSEEKSIZE > IVSIZE
    PUSHn( do_tell(gv) );
#else
    PUSHi( do_tell(gv) );
#endif
    RETURN;
}

PP(pp_sysseek)
{
    dVAR; dSP;
    const int whence = POPi;
#if LSEEKSIZE > IVSIZE
    const Off_t offset = (Off_t)SvNVx(POPs);
#else
    const Off_t offset = (Off_t)SvIVx(POPs);
#endif

    GV * const gv = PL_last_in_gv = MUTABLE_GV(POPs);
    IO *io;

    if (gv && (io = GvIO(gv))) {
	MAGIC * const mg = SvTIED_mg((const SV *)io, PERL_MAGIC_tiedscalar);
	if (mg) {
#if LSEEKSIZE > IVSIZE
	    SV *const offset_sv = newSVnv((NV) offset);
#else
	    SV *const offset_sv = newSViv(offset);
#endif

	    return tied_handle_method2("SEEK", SP, io, mg, offset_sv,
				       newSViv(whence));
	}
    }

    if (PL_op->op_type == OP_SEEK)
	PUSHs(boolSV(do_seek(gv, offset, whence)));
    else {
	const Off_t sought = do_sysseek(gv, offset, whence);
        if (sought < 0)
            PUSHs(&PL_sv_undef);
        else {
            SV* const sv = sought ?
#if LSEEKSIZE > IVSIZE
                newSVnv((NV)sought)
#else
                newSViv(sought)
#endif
                : newSVpvn(zero_but_true, ZBTLEN);
            mPUSHs(sv);
        }
    }
    RETURN;
}

PP(pp_truncate)
{
    dVAR;
    dSP;
    /* There seems to be no consensus on the length type of truncate()
     * and ftruncate(), both off_t and size_t have supporters. In
     * general one would think that when using large files, off_t is
     * at least as wide as size_t, so using an off_t should be okay. */
    /* XXX Configure probe for the length type of *truncate() needed XXX */
    Off_t len;

#if Off_t_size > IVSIZE
    len = (Off_t)POPn;
#else
    len = (Off_t)POPi;
#endif
    /* Checking for length < 0 is problematic as the type might or
     * might not be signed: if it is not, clever compilers will moan. */
    /* XXX Configure probe for the signedness of the length type of *truncate() needed? XXX */
    SETERRNO(0,0);
    {
	int result = 1;
	GV *tmpgv;
	IO *io;

	if (PL_op->op_flags & OPf_SPECIAL) {
	    tmpgv = gv_fetchsv(POPs, 0, SVt_PVIO);

	do_ftruncate_gv:
	    if (!GvIO(tmpgv))
		result = 0;
	    else {
		PerlIO *fp;
		io = GvIOp(tmpgv);
	    do_ftruncate_io:
		TAINT_PROPER("truncate");
		if (!(fp = IoIFP(io))) {
		    result = 0;
		}
		else {
		    PerlIO_flush(fp);
#ifdef HAS_TRUNCATE
		    if (ftruncate(PerlIO_fileno(fp), len) < 0)
#else
		    if (my_chsize(PerlIO_fileno(fp), len) < 0)
#endif
			result = 0;
		}
	    }
	}
	else {
	    SV * const sv = POPs;
	    const char *name;

	    if (isGV_with_GP(sv)) {
	        tmpgv = MUTABLE_GV(sv);		/* *main::FRED for example */
		goto do_ftruncate_gv;
	    }
	    else if (SvROK(sv) && isGV_with_GP(SvRV(sv))) {
	        tmpgv = MUTABLE_GV(SvRV(sv));	/* \*main::FRED for example */
		goto do_ftruncate_gv;
	    }
	    else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVIO) {
		io = MUTABLE_IO(SvRV(sv)); /* *main::FRED{IO} for example */
		goto do_ftruncate_io;
	    }

	    name = SvPV_nolen_const(sv);
	    TAINT_PROPER("truncate");
#ifdef HAS_TRUNCATE
	    if (truncate(name, len) < 0)
	        result = 0;
#else
	    {
		const int tmpfd = PerlLIO_open(name, O_RDWR);

		if (tmpfd < 0)
		    result = 0;
		else {
		    if (my_chsize(tmpfd, len) < 0)
		        result = 0;
		    PerlLIO_close(tmpfd);
		}
	    }
#endif
	}

	if (result)
	    RETPUSHYES;
	if (!errno)
	    SETERRNO(EBADF,RMS_IFI);
	RETPUSHUNDEF;
    }
}

PP(pp_ioctl)
{
    dVAR; dSP; dTARGET;
    SV * const argsv = POPs;
    const unsigned int func = POPu;
    const int optype = PL_op->op_type;
    GV * const gv = MUTABLE_GV(POPs);
    IO * const io = gv ? GvIOn(gv) : NULL;
    char *s;
    IV retval;

    if (!io || !argsv || !IoIFP(io)) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	SETERRNO(EBADF,RMS_IFI);	/* well, sort of... */
	RETPUSHUNDEF;
    }

    if (SvPOK(argsv) || !SvNIOK(argsv)) {
	STRLEN len;
	STRLEN need;
	s = SvPV_force(argsv, len);
	need = IOCPARM_LEN(func);
	if (len < need) {
	    s = Sv_Grow(argsv, need + 1);
	    SvCUR_set(argsv, need);
	}

	s[SvCUR(argsv)] = 17;	/* a little sanity check here */
    }
    else {
	retval = SvIV(argsv);
	s = INT2PTR(char*,retval);		/* ouch */
    }

    TAINT_PROPER(PL_op_desc[optype]);

    if (optype == OP_IOCTL)
#ifdef HAS_IOCTL
	retval = PerlLIO_ioctl(PerlIO_fileno(IoIFP(io)), func, s);
#else
	DIE(aTHX_ "ioctl is not implemented");
#endif
    else
#ifndef HAS_FCNTL
      DIE(aTHX_ "fcntl is not implemented");
#else
#if defined(OS2) && defined(__EMX__)
	retval = fcntl(PerlIO_fileno(IoIFP(io)), func, (int)s);
#else
	retval = fcntl(PerlIO_fileno(IoIFP(io)), func, s);
#endif
#endif

#if defined(HAS_IOCTL) || defined(HAS_FCNTL)
    if (SvPOK(argsv)) {
	if (s[SvCUR(argsv)] != 17)
	    DIE(aTHX_ "Possible memory corruption: %s overflowed 3rd argument",
		OP_NAME(PL_op));
	s[SvCUR(argsv)] = 0;		/* put our null back */
	SvSETMAGIC(argsv);		/* Assume it has changed */
    }

    if (retval == -1)
	RETPUSHUNDEF;
    if (retval != 0) {
	PUSHi(retval);
    }
    else {
	PUSHp(zero_but_true, ZBTLEN);
    }
#endif
    RETURN;
}

PP(pp_flock)
{
#ifdef FLOCK
    dVAR; dSP; dTARGET;
    I32 value;
    IO *io = NULL;
    PerlIO *fp;
    const int argtype = POPi;
    GV * const gv = (MAXARG == 0) ? PL_last_in_gv : MUTABLE_GV(POPs);

    if (gv && (io = GvIO(gv)))
	fp = IoIFP(io);
    else {
	fp = NULL;
	io = NULL;
    }
    /* XXX Looks to me like io is always NULL at this point */
    if (fp) {
	(void)PerlIO_flush(fp);
	value = (I32)(PerlLIO_flock(PerlIO_fileno(fp), argtype) >= 0);
    }
    else {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	value = 0;
	SETERRNO(EBADF,RMS_IFI);
    }
    PUSHi(value);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "flock()");
#endif
}

/* Sockets. */

PP(pp_socket)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    const int protocol = POPi;
    const int type = POPi;
    const int domain = POPi;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = gv ? GvIOn(gv) : NULL;
    int fd;

    if (!gv || !io) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
	    report_evil_fh(gv, io, PL_op->op_type);
	if (io && IoIFP(io))
	    do_close(gv, FALSE);
	SETERRNO(EBADF,LIB_INVARG);
	RETPUSHUNDEF;
    }

    if (IoIFP(io))
	do_close(gv, FALSE);

    TAINT_PROPER("socket");
    fd = PerlSock_socket(domain, type, protocol);
    if (fd < 0)
	RETPUSHUNDEF;
    IoIFP(io) = PerlIO_fdopen(fd, "r"SOCKET_OPEN_MODE);	/* stdio gets confused about sockets */
    IoOFP(io) = PerlIO_fdopen(fd, "w"SOCKET_OPEN_MODE);
    IoTYPE(io) = IoTYPE_SOCKET;
    if (!IoIFP(io) || !IoOFP(io)) {
	if (IoIFP(io)) PerlIO_close(IoIFP(io));
	if (IoOFP(io)) PerlIO_close(IoOFP(io));
	if (!IoIFP(io) && !IoOFP(io)) PerlLIO_close(fd);
	RETPUSHUNDEF;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd, F_SETFD, fd > PL_maxsysfd);	/* ensure close-on-exec */
#endif

#ifdef EPOC
    setbuf( IoIFP(io), NULL); /* EPOC gets confused about sockets */
#endif

    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "socket");
#endif
}

PP(pp_sockpair)
{
#if defined (HAS_SOCKETPAIR) || (defined (HAS_SOCKET) && defined(SOCK_DGRAM) && defined(AF_INET) && defined(PF_INET))
    dVAR; dSP;
    const int protocol = POPi;
    const int type = POPi;
    const int domain = POPi;
    GV * const gv2 = MUTABLE_GV(POPs);
    GV * const gv1 = MUTABLE_GV(POPs);
    register IO * const io1 = gv1 ? GvIOn(gv1) : NULL;
    register IO * const io2 = gv2 ? GvIOn(gv2) : NULL;
    int fd[2];

    if (!gv1 || !gv2 || !io1 || !io2) {
	if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
	    if (!gv1 || !io1)
		report_evil_fh(gv1, io1, PL_op->op_type);
	    if (!gv2 || !io2)
		report_evil_fh(gv1, io2, PL_op->op_type);
	}
	if (io1 && IoIFP(io1))
	    do_close(gv1, FALSE);
	if (io2 && IoIFP(io2))
	    do_close(gv2, FALSE);
	RETPUSHUNDEF;
    }

    if (IoIFP(io1))
	do_close(gv1, FALSE);
    if (IoIFP(io2))
	do_close(gv2, FALSE);

    TAINT_PROPER("socketpair");
    if (PerlSock_socketpair(domain, type, protocol, fd) < 0)
	RETPUSHUNDEF;
    IoIFP(io1) = PerlIO_fdopen(fd[0], "r"SOCKET_OPEN_MODE);
    IoOFP(io1) = PerlIO_fdopen(fd[0], "w"SOCKET_OPEN_MODE);
    IoTYPE(io1) = IoTYPE_SOCKET;
    IoIFP(io2) = PerlIO_fdopen(fd[1], "r"SOCKET_OPEN_MODE);
    IoOFP(io2) = PerlIO_fdopen(fd[1], "w"SOCKET_OPEN_MODE);
    IoTYPE(io2) = IoTYPE_SOCKET;
    if (!IoIFP(io1) || !IoOFP(io1) || !IoIFP(io2) || !IoOFP(io2)) {
	if (IoIFP(io1)) PerlIO_close(IoIFP(io1));
	if (IoOFP(io1)) PerlIO_close(IoOFP(io1));
	if (!IoIFP(io1) && !IoOFP(io1)) PerlLIO_close(fd[0]);
	if (IoIFP(io2)) PerlIO_close(IoIFP(io2));
	if (IoOFP(io2)) PerlIO_close(IoOFP(io2));
	if (!IoIFP(io2) && !IoOFP(io2)) PerlLIO_close(fd[1]);
	RETPUSHUNDEF;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd[0],F_SETFD,fd[0] > PL_maxsysfd);	/* ensure close-on-exec */
    fcntl(fd[1],F_SETFD,fd[1] > PL_maxsysfd);	/* ensure close-on-exec */
#endif

    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "socketpair");
#endif
}

PP(pp_bind)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    SV * const addrsv = POPs;
    /* OK, so on what platform does bind modify addr?  */
    const char *addr;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);
    STRLEN len;

    if (!io || !IoIFP(io))
	goto nuts;

    addr = SvPV_const(addrsv, len);
    TAINT_PROPER("bind");
    if (PerlSock_bind(PerlIO_fileno(IoIFP(io)), (struct sockaddr *)addr, len) >= 0)
	RETPUSHYES;
    else
	RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "bind");
#endif
}

PP(pp_connect)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    SV * const addrsv = POPs;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);
    const char *addr;
    STRLEN len;

    if (!io || !IoIFP(io))
	goto nuts;

    addr = SvPV_const(addrsv, len);
    TAINT_PROPER("connect");
    if (PerlSock_connect(PerlIO_fileno(IoIFP(io)), (struct sockaddr *)addr, len) >= 0)
	RETPUSHYES;
    else
	RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "connect");
#endif
}

PP(pp_listen)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    const int backlog = POPi;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = gv ? GvIOn(gv) : NULL;

    if (!gv || !io || !IoIFP(io))
	goto nuts;

    if (PerlSock_listen(PerlIO_fileno(IoIFP(io)), backlog) >= 0)
	RETPUSHYES;
    else
	RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "listen");
#endif
}

PP(pp_accept)
{
#ifdef HAS_SOCKET
    dVAR; dSP; dTARGET;
    register IO *nstio;
    register IO *gstio;
    char namebuf[MAXPATHLEN];
#if (defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)) || defined(MPE) || defined(__QNXNTO__)
    Sock_size_t len = sizeof (struct sockaddr_in);
#else
    Sock_size_t len = sizeof namebuf;
#endif
    GV * const ggv = MUTABLE_GV(POPs);
    GV * const ngv = MUTABLE_GV(POPs);
    int fd;

    if (!ngv)
	goto badexit;
    if (!ggv)
	goto nuts;

    gstio = GvIO(ggv);
    if (!gstio || !IoIFP(gstio))
	goto nuts;

    nstio = GvIOn(ngv);
    fd = PerlSock_accept(PerlIO_fileno(IoIFP(gstio)), (struct sockaddr *) namebuf, &len);
#if defined(OEMVS)
    if (len == 0) {
	/* Some platforms indicate zero length when an AF_UNIX client is
	 * not bound. Simulate a non-zero-length sockaddr structure in
	 * this case. */
	namebuf[0] = 0;        /* sun_len */
	namebuf[1] = AF_UNIX;  /* sun_family */
	len = 2;
    }
#endif

    if (fd < 0)
	goto badexit;
    if (IoIFP(nstio))
	do_close(ngv, FALSE);
    IoIFP(nstio) = PerlIO_fdopen(fd, "r"SOCKET_OPEN_MODE);
    IoOFP(nstio) = PerlIO_fdopen(fd, "w"SOCKET_OPEN_MODE);
    IoTYPE(nstio) = IoTYPE_SOCKET;
    if (!IoIFP(nstio) || !IoOFP(nstio)) {
	if (IoIFP(nstio)) PerlIO_close(IoIFP(nstio));
	if (IoOFP(nstio)) PerlIO_close(IoOFP(nstio));
	if (!IoIFP(nstio) && !IoOFP(nstio)) PerlLIO_close(fd);
	goto badexit;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd, F_SETFD, fd > PL_maxsysfd);	/* ensure close-on-exec */
#endif

#ifdef EPOC
    len = sizeof (struct sockaddr_in); /* EPOC somehow truncates info */
    setbuf( IoIFP(nstio), NULL); /* EPOC gets confused about sockets */
#endif
#ifdef __SCO_VERSION__
    len = sizeof (struct sockaddr_in); /* OpenUNIX 8 somehow truncates info */
#endif

    PUSHp(namebuf, len);
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(ggv, ggv ? GvIO(ggv) : 0, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);

badexit:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, "accept");
#endif
}

PP(pp_shutdown)
{
#ifdef HAS_SOCKET
    dVAR; dSP; dTARGET;
    const int how = POPi;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io || !IoIFP(io))
	goto nuts;

    PUSHi( PerlSock_shutdown(PerlIO_fileno(IoIFP(io)), how) >= 0 );
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "shutdown");
#endif
}

PP(pp_ssockopt)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    const int optype = PL_op->op_type;
    SV * const sv = (optype == OP_GSOCKOPT) ? sv_2mortal(newSV(257)) : POPs;
    const unsigned int optname = (unsigned int) POPi;
    const unsigned int lvl = (unsigned int) POPi;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);
    int fd;
    Sock_size_t len;

    if (!io || !IoIFP(io))
	goto nuts;

    fd = PerlIO_fileno(IoIFP(io));
    switch (optype) {
    case OP_GSOCKOPT:
	SvGROW(sv, 257);
	(void)SvPOK_only(sv);
	SvCUR_set(sv,256);
	*SvEND(sv) ='\0';
	len = SvCUR(sv);
	if (PerlSock_getsockopt(fd, lvl, optname, SvPVX(sv), &len) < 0)
	    goto nuts2;
	SvCUR_set(sv, len);
	*SvEND(sv) ='\0';
	PUSHs(sv);
	break;
    case OP_SSOCKOPT: {
#if defined(__SYMBIAN32__)
# define SETSOCKOPT_OPTION_VALUE_T void *
#else
# define SETSOCKOPT_OPTION_VALUE_T const char *
#endif
	/* XXX TODO: We need to have a proper type (a Configure probe,
	 * etc.) for what the C headers think of the third argument of
	 * setsockopt(), the option_value read-only buffer: is it
	 * a "char *", or a "void *", const or not.  Some compilers
	 * don't take kindly to e.g. assuming that "char *" implicitly
	 * promotes to a "void *", or to explicitly promoting/demoting
	 * consts to non/vice versa.  The "const void *" is the SUS
	 * definition, but that does not fly everywhere for the above
	 * reasons. */
	    SETSOCKOPT_OPTION_VALUE_T buf;
	    int aint;
	    if (SvPOKp(sv)) {
		STRLEN l;
		buf = (SETSOCKOPT_OPTION_VALUE_T) SvPV_const(sv, l);
		len = l;
	    }
	    else {
		aint = (int)SvIV(sv);
		buf = (SETSOCKOPT_OPTION_VALUE_T) &aint;
		len = sizeof(int);
	    }
	    if (PerlSock_setsockopt(fd, lvl, optname, buf, len) < 0)
		goto nuts2;
	    PUSHs(&PL_sv_yes);
	}
	break;
    }
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, optype);
    SETERRNO(EBADF,SS_IVCHAN);
nuts2:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, PL_op_desc[PL_op->op_type]);
#endif
}

PP(pp_getpeername)
{
#ifdef HAS_SOCKET
    dVAR; dSP;
    const int optype = PL_op->op_type;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);
    Sock_size_t len;
    SV *sv;
    int fd;

    if (!io || !IoIFP(io))
	goto nuts;

    sv = sv_2mortal(newSV(257));
    (void)SvPOK_only(sv);
    len = 256;
    SvCUR_set(sv, len);
    *SvEND(sv) ='\0';
    fd = PerlIO_fileno(IoIFP(io));
    switch (optype) {
    case OP_GETSOCKNAME:
	if (PerlSock_getsockname(fd, (struct sockaddr *)SvPVX(sv), &len) < 0)
	    goto nuts2;
	break;
    case OP_GETPEERNAME:
	if (PerlSock_getpeername(fd, (struct sockaddr *)SvPVX(sv), &len) < 0)
	    goto nuts2;
#if defined(VMS_DO_SOCKETS) && defined (DECCRTL_SOCKETS)
	{
	    static const char nowhere[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
	    /* If the call succeeded, make sure we don't have a zeroed port/addr */
	    if (((struct sockaddr *)SvPVX_const(sv))->sa_family == AF_INET &&
		!memcmp(SvPVX_const(sv) + sizeof(u_short), nowhere,
			sizeof(u_short) + sizeof(struct in_addr))) {
		goto nuts2;	
	    }
	}
#endif
	break;
    }
#ifdef BOGUS_GETNAME_RETURN
    /* Interactive Unix, getpeername() and getsockname()
      does not return valid namelen */
    if (len == BOGUS_GETNAME_RETURN)
	len = sizeof(struct sockaddr);
#endif
    SvCUR_set(sv, len);
    *SvEND(sv) ='\0';
    PUSHs(sv);
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
	report_evil_fh(gv, io, optype);
    SETERRNO(EBADF,SS_IVCHAN);
nuts2:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, PL_op_desc[PL_op->op_type]);
#endif
}

/* Stat calls. */

PP(pp_stat)
{
    dVAR;
    dSP;
    GV *gv = NULL;
    IO *io;
    I32 gimme;
    I32 max = 13;

    if (PL_op->op_flags & OPf_REF) {
	gv = cGVOP_gv;
	if (PL_op->op_type == OP_LSTAT) {
	    if (gv != PL_defgv) {
	    do_fstat_warning_check:
		Perl_ck_warner(aTHX_ packWARN(WARN_IO),
			       "lstat() on filehandle %s", gv ? GvENAME(gv) : "");
	    } else if (PL_laststype != OP_LSTAT)
		Perl_croak(aTHX_ "The stat preceding lstat() wasn't an lstat");
	}

      do_fstat:
	if (gv != PL_defgv) {
	    PL_laststype = OP_STAT;
	    PL_statgv = gv;
	    sv_setpvs(PL_statname, "");
            if(gv) {
                io = GvIO(gv);
                do_fstat_have_io:
                if (io) {
                    if (IoIFP(io)) {
                        PL_laststatval = 
                            PerlLIO_fstat(PerlIO_fileno(IoIFP(io)), &PL_statcache);   
                    } else if (IoDIRP(io)) {
                        PL_laststatval =
                            PerlLIO_fstat(my_dirfd(IoDIRP(io)), &PL_statcache);
                    } else {
                        PL_laststatval = -1;
                    }
	        }
            }
        }

	if (PL_laststatval < 0) {
	    if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
		report_evil_fh(gv, GvIO(gv), PL_op->op_type);
	    max = 0;
	}
    }
    else {
	SV* const sv = POPs;
	if (isGV_with_GP(sv)) {
	    gv = MUTABLE_GV(sv);
	    goto do_fstat;
	} else if(SvROK(sv) && isGV_with_GP(SvRV(sv))) {
            gv = MUTABLE_GV(SvRV(sv));
            if (PL_op->op_type == OP_LSTAT)
                goto do_fstat_warning_check;
            goto do_fstat;
        } else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVIO) { 
            io = MUTABLE_IO(SvRV(sv));
            if (PL_op->op_type == OP_LSTAT)
                goto do_fstat_warning_check;
            goto do_fstat_have_io; 
        }
        
	sv_setpv(PL_statname, SvPV_nolen_const(sv));
	PL_statgv = NULL;
	PL_laststype = PL_op->op_type;
	if (PL_op->op_type == OP_LSTAT)
	    PL_laststatval = PerlLIO_lstat(SvPV_nolen_const(PL_statname), &PL_statcache);
	else
	    PL_laststatval = PerlLIO_stat(SvPV_nolen_const(PL_statname), &PL_statcache);
	if (PL_laststatval < 0) {
	    if (ckWARN(WARN_NEWLINE) && strchr(SvPV_nolen_const(PL_statname), '\n'))
		Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "stat");
	    max = 0;
	}
    }

    gimme = GIMME_V;
    if (gimme != G_ARRAY) {
	if (gimme != G_VOID)
	    XPUSHs(boolSV(max));
	RETURN;
    }
    if (max) {
	EXTEND(SP, max);
	EXTEND_MORTAL(max);
	mPUSHi(PL_statcache.st_dev);
	mPUSHi(PL_statcache.st_ino);
	mPUSHu(PL_statcache.st_mode);
	mPUSHu(PL_statcache.st_nlink);
#if Uid_t_size > IVSIZE
	mPUSHn(PL_statcache.st_uid);
#else
#   if Uid_t_sign <= 0
	mPUSHi(PL_statcache.st_uid);
#   else
	mPUSHu(PL_statcache.st_uid);
#   endif
#endif
#if Gid_t_size > IVSIZE
	mPUSHn(PL_statcache.st_gid);
#else
#   if Gid_t_sign <= 0
	mPUSHi(PL_statcache.st_gid);
#   else
	mPUSHu(PL_statcache.st_gid);
#   endif
#endif
#ifdef USE_STAT_RDEV
	mPUSHi(PL_statcache.st_rdev);
#else
	PUSHs(newSVpvs_flags("", SVs_TEMP));
#endif
#if Off_t_size > IVSIZE
	mPUSHn(PL_statcache.st_size);
#else
	mPUSHi(PL_statcache.st_size);
#endif
#ifdef BIG_TIME
	mPUSHn(PL_statcache.st_atime);
	mPUSHn(PL_statcache.st_mtime);
	mPUSHn(PL_statcache.st_ctime);
#else
	mPUSHi(PL_statcache.st_atime);
	mPUSHi(PL_statcache.st_mtime);
	mPUSHi(PL_statcache.st_ctime);
#endif
#ifdef USE_STAT_BLOCKS
	mPUSHu(PL_statcache.st_blksize);
	mPUSHu(PL_statcache.st_blocks);
#else
	PUSHs(newSVpvs_flags("", SVs_TEMP));
	PUSHs(newSVpvs_flags("", SVs_TEMP));
#endif
    }
    RETURN;
}

#define tryAMAGICftest_MG(chr) STMT_START { \
	if ( (SvFLAGS(TOPs) & (SVf_ROK|SVs_GMG)) \
		&& S_try_amagic_ftest(aTHX_ chr)) \
	    return NORMAL; \
    } STMT_END

STATIC bool
S_try_amagic_ftest(pTHX_ char chr) {
    dVAR;
    dSP;
    SV* const arg = TOPs;

    assert(chr != '?');
    SvGETMAGIC(arg);

    if ((PL_op->op_flags & OPf_KIDS)
	    && SvAMAGIC(TOPs))
    {
	const char tmpchr = chr;
	const OP *next;
	SV * const tmpsv = amagic_call(arg,
				newSVpvn_flags(&tmpchr, 1, SVs_TEMP),
				ftest_amg, AMGf_unary);

	if (!tmpsv)
	    return FALSE;

	SPAGAIN;

	next = PL_op->op_next;
	if (next->op_type >= OP_FTRREAD &&
	    next->op_type <= OP_FTBINARY &&
	    next->op_private & OPpFT_STACKED
	) {
	    if (SvTRUE(tmpsv))
		/* leave the object alone */
		return TRUE;
	}

	SETs(tmpsv);
	PUTBACK;
	return TRUE;
    }
    return FALSE;
}


/* This macro is used by the stacked filetest operators :
 * if the previous filetest failed, short-circuit and pass its value.
 * Else, discard it from the stack and continue. --rgs
 */
#define STACKED_FTEST_CHECK if (PL_op->op_private & OPpFT_STACKED) { \
	if (!SvTRUE(TOPs)) { RETURN; } \
	else { (void)POPs; PUTBACK; } \
    }

PP(pp_ftrread)
{
    dVAR;
    I32 result;
    /* Not const, because things tweak this below. Not bool, because there's
       no guarantee that OPp_FT_ACCESS is <= CHAR_MAX  */
#if defined(HAS_ACCESS) || defined (PERL_EFF_ACCESS)
    I32 use_access = PL_op->op_private & OPpFT_ACCESS;
    /* Giving some sort of initial value silences compilers.  */
#  ifdef R_OK
    int access_mode = R_OK;
#  else
    int access_mode = 0;
#  endif
#else
    /* access_mode is never used, but leaving use_access in makes the
       conditional compiling below much clearer.  */
    I32 use_access = 0;
#endif
    int stat_mode = S_IRUSR;

    bool effective = FALSE;
    char opchar = '?';
    dSP;

    switch (PL_op->op_type) {
    case OP_FTRREAD:	opchar = 'R'; break;
    case OP_FTRWRITE:	opchar = 'W'; break;
    case OP_FTREXEC:	opchar = 'X'; break;
    case OP_FTEREAD:	opchar = 'r'; break;
    case OP_FTEWRITE:	opchar = 'w'; break;
    case OP_FTEEXEC:	opchar = 'x'; break;
    }
    tryAMAGICftest_MG(opchar);

    STACKED_FTEST_CHECK;

    switch (PL_op->op_type) {
    case OP_FTRREAD:
#if !(defined(HAS_ACCESS) && defined(R_OK))
	use_access = 0;
#endif
	break;

    case OP_FTRWRITE:
#if defined(HAS_ACCESS) && defined(W_OK)
	access_mode = W_OK;
#else
	use_access = 0;
#endif
	stat_mode = S_IWUSR;
	break;

    case OP_FTREXEC:
#if defined(HAS_ACCESS) && defined(X_OK)
	access_mode = X_OK;
#else
	use_access = 0;
#endif
	stat_mode = S_IXUSR;
	break;

    case OP_FTEWRITE:
#ifdef PERL_EFF_ACCESS
	access_mode = W_OK;
#endif
	stat_mode = S_IWUSR;
	/* fall through */

    case OP_FTEREAD:
#ifndef PERL_EFF_ACCESS
	use_access = 0;
#endif
	effective = TRUE;
	break;

    case OP_FTEEXEC:
#ifdef PERL_EFF_ACCESS
	access_mode = X_OK;
#else
	use_access = 0;
#endif
	stat_mode = S_IXUSR;
	effective = TRUE;
	break;
    }

    if (use_access) {
#if defined(HAS_ACCESS) || defined (PERL_EFF_ACCESS)
	const char *name = POPpx;
	if (effective) {
#  ifdef PERL_EFF_ACCESS
	    result = PERL_EFF_ACCESS(name, access_mode);
#  else
	    DIE(aTHX_ "panic: attempt to call PERL_EFF_ACCESS in %s",
		OP_NAME(PL_op));
#  endif
	}
	else {
#  ifdef HAS_ACCESS
	    result = access(name, access_mode);
#  else
	    DIE(aTHX_ "panic: attempt to call access() in %s", OP_NAME(PL_op));
#  endif
	}
	if (result == 0)
	    RETPUSHYES;
	if (result < 0)
	    RETPUSHUNDEF;
	RETPUSHNO;
#endif
    }

    result = my_stat_flags(0);
    SPAGAIN;
    if (result < 0)
	RETPUSHUNDEF;
    if (cando(stat_mode, effective, &PL_statcache))
	RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftis)
{
    dVAR;
    I32 result;
    const int op_type = PL_op->op_type;
    char opchar = '?';
    dSP;

    switch (op_type) {
    case OP_FTIS:	opchar = 'e'; break;
    case OP_FTSIZE:	opchar = 's'; break;
    case OP_FTMTIME:	opchar = 'M'; break;
    case OP_FTCTIME:	opchar = 'C'; break;
    case OP_FTATIME:	opchar = 'A'; break;
    }
    tryAMAGICftest_MG(opchar);

    STACKED_FTEST_CHECK;

    result = my_stat_flags(0);
    SPAGAIN;
    if (result < 0)
	RETPUSHUNDEF;
    if (op_type == OP_FTIS)
	RETPUSHYES;
    {
	/* You can't dTARGET inside OP_FTIS, because you'll get
	   "panic: pad_sv po" - the op is not flagged to have a target.  */
	dTARGET;
	switch (op_type) {
	case OP_FTSIZE:
#if Off_t_size > IVSIZE
	    PUSHn(PL_statcache.st_size);
#else
	    PUSHi(PL_statcache.st_size);
#endif
	    break;
	case OP_FTMTIME:
	    PUSHn( (((NV)PL_basetime - PL_statcache.st_mtime)) / 86400.0 );
	    break;
	case OP_FTATIME:
	    PUSHn( (((NV)PL_basetime - PL_statcache.st_atime)) / 86400.0 );
	    break;
	case OP_FTCTIME:
	    PUSHn( (((NV)PL_basetime - PL_statcache.st_ctime)) / 86400.0 );
	    break;
	}
    }
    RETURN;
}

PP(pp_ftrowned)
{
    dVAR;
    I32 result;
    char opchar = '?';
    dSP;

    switch (PL_op->op_type) {
    case OP_FTROWNED:	opchar = 'O'; break;
    case OP_FTEOWNED:	opchar = 'o'; break;
    case OP_FTZERO:	opchar = 'z'; break;
    case OP_FTSOCK:	opchar = 'S'; break;
    case OP_FTCHR:	opchar = 'c'; break;
    case OP_FTBLK:	opchar = 'b'; break;
    case OP_FTFILE:	opchar = 'f'; break;
    case OP_FTDIR:	opchar = 'd'; break;
    case OP_FTPIPE:	opchar = 'p'; break;
    case OP_FTSUID:	opchar = 'u'; break;
    case OP_FTSGID:	opchar = 'g'; break;
    case OP_FTSVTX:	opchar = 'k'; break;
    }
    tryAMAGICftest_MG(opchar);

    /* I believe that all these three are likely to be defined on most every
       system these days.  */
#ifndef S_ISUID
    if(PL_op->op_type == OP_FTSUID)
	RETPUSHNO;
#endif
#ifndef S_ISGID
    if(PL_op->op_type == OP_FTSGID)
	RETPUSHNO;
#endif
#ifndef S_ISVTX
    if(PL_op->op_type == OP_FTSVTX)
	RETPUSHNO;
#endif

    STACKED_FTEST_CHECK;

    result = my_stat_flags(0);
    SPAGAIN;
    if (result < 0)
	RETPUSHUNDEF;
    switch (PL_op->op_type) {
    case OP_FTROWNED:
	if (PL_statcache.st_uid == PL_uid)
	    RETPUSHYES;
	break;
    case OP_FTEOWNED:
	if (PL_statcache.st_uid == PL_euid)
	    RETPUSHYES;
	break;
    case OP_FTZERO:
	if (PL_statcache.st_size == 0)
	    RETPUSHYES;
	break;
    case OP_FTSOCK:
	if (S_ISSOCK(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
    case OP_FTCHR:
	if (S_ISCHR(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
    case OP_FTBLK:
	if (S_ISBLK(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
    case OP_FTFILE:
	if (S_ISREG(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
    case OP_FTDIR:
	if (S_ISDIR(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
    case OP_FTPIPE:
	if (S_ISFIFO(PL_statcache.st_mode))
	    RETPUSHYES;
	break;
#ifdef S_ISUID
    case OP_FTSUID:
	if (PL_statcache.st_mode & S_ISUID)
	    RETPUSHYES;
	break;
#endif
#ifdef S_ISGID
    case OP_FTSGID:
	if (PL_statcache.st_mode & S_ISGID)
	    RETPUSHYES;
	break;
#endif
#ifdef S_ISVTX
    case OP_FTSVTX:
	if (PL_statcache.st_mode & S_ISVTX)
	    RETPUSHYES;
	break;
#endif
    }
    RETPUSHNO;
}

PP(pp_ftlink)
{
    dVAR;
    dSP;
    I32 result;

    tryAMAGICftest_MG('l');
    result = my_lstat_flags(0);
    SPAGAIN;

    if (result < 0)
	RETPUSHUNDEF;
    if (S_ISLNK(PL_statcache.st_mode))
	RETPUSHYES;
    RETPUSHNO;
}

PP(pp_fttty)
{
    dVAR;
    dSP;
    int fd;
    GV *gv;
    SV *tmpsv = NULL;
    char *name = NULL;
    STRLEN namelen;

    tryAMAGICftest_MG('t');

    STACKED_FTEST_CHECK;

    if (PL_op->op_flags & OPf_REF)
	gv = cGVOP_gv;
    else if (isGV(TOPs))
	gv = MUTABLE_GV(POPs);
    else if (SvROK(TOPs) && isGV(SvRV(TOPs)))
	gv = MUTABLE_GV(SvRV(POPs));
    else {
	tmpsv = POPs;
	name = SvPV_nomg(tmpsv, namelen);
	gv = gv_fetchpvn_flags(name, namelen, SvUTF8(tmpsv), SVt_PVIO);
    }

    if (GvIO(gv) && IoIFP(GvIOp(gv)))
	fd = PerlIO_fileno(IoIFP(GvIOp(gv)));
    else if (tmpsv && SvOK(tmpsv)) {
	if (isDIGIT(*name))
	    fd = atoi(name);
	else 
	    RETPUSHUNDEF;
    }
    else
	RETPUSHUNDEF;
    if (PerlLIO_isatty(fd))
	RETPUSHYES;
    RETPUSHNO;
}

#if defined(atarist) /* this will work with atariST. Configure will
			make guesses for other systems. */
# define FILE_base(f) ((f)->_base)
# define FILE_ptr(f) ((f)->_ptr)
# define FILE_cnt(f) ((f)->_cnt)
# define FILE_bufsiz(f) ((f)->_cnt + ((f)->_ptr - (f)->_base))
#endif

PP(pp_fttext)
{
    dVAR;
    dSP;
    I32 i;
    I32 len;
    I32 odd = 0;
    STDCHAR tbuf[512];
    register STDCHAR *s;
    register IO *io;
    register SV *sv;
    GV *gv;
    PerlIO *fp;

    tryAMAGICftest_MG(PL_op->op_type == OP_FTTEXT ? 'T' : 'B');

    STACKED_FTEST_CHECK;

    if (PL_op->op_flags & OPf_REF)
	gv = cGVOP_gv;
    else if (isGV(TOPs))
	gv = MUTABLE_GV(POPs);
    else if (SvROK(TOPs) && isGV(SvRV(TOPs)))
	gv = MUTABLE_GV(SvRV(POPs));
    else
	gv = NULL;

    if (gv) {
	EXTEND(SP, 1);
	if (gv == PL_defgv) {
	    if (PL_statgv)
		io = GvIO(PL_statgv);
	    else {
		sv = PL_statname;
		goto really_filename;
	    }
	}
	else {
	    PL_statgv = gv;
	    PL_laststatval = -1;
	    sv_setpvs(PL_statname, "");
	    io = GvIO(PL_statgv);
	}
	if (io && IoIFP(io)) {
	    if (! PerlIO_has_base(IoIFP(io)))
		DIE(aTHX_ "-T and -B not implemented on filehandles");
	    PL_laststatval = PerlLIO_fstat(PerlIO_fileno(IoIFP(io)), &PL_statcache);
	    if (PL_laststatval < 0)
		RETPUSHUNDEF;
	    if (S_ISDIR(PL_statcache.st_mode)) { /* handle NFS glitch */
		if (PL_op->op_type == OP_FTTEXT)
		    RETPUSHNO;
		else
		    RETPUSHYES;
            }
	    if (PerlIO_get_cnt(IoIFP(io)) <= 0) {
		i = PerlIO_getc(IoIFP(io));
		if (i != EOF)
		    (void)PerlIO_ungetc(IoIFP(io),i);
	    }
	    if (PerlIO_get_cnt(IoIFP(io)) <= 0)	/* null file is anything */
		RETPUSHYES;
	    len = PerlIO_get_bufsiz(IoIFP(io));
	    s = (STDCHAR *) PerlIO_get_base(IoIFP(io));
	    /* sfio can have large buffers - limit to 512 */
	    if (len > 512)
		len = 512;
	}
	else {
	    if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
		gv = cGVOP_gv;
		report_evil_fh(gv, GvIO(gv), PL_op->op_type);
	    }
	    SETERRNO(EBADF,RMS_IFI);
	    RETPUSHUNDEF;
	}
    }
    else {
	sv = POPs;
      really_filename:
	PL_statgv = NULL;
	PL_laststype = OP_STAT;
	sv_setpv(PL_statname, SvPV_nomg_const_nolen(sv));
	if (!(fp = PerlIO_open(SvPVX_const(PL_statname), "r"))) {
	    if (ckWARN(WARN_NEWLINE) && strchr(SvPV_nolen_const(PL_statname),
					       '\n'))
		Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "open");
	    RETPUSHUNDEF;
	}
	PL_laststatval = PerlLIO_fstat(PerlIO_fileno(fp), &PL_statcache);
	if (PL_laststatval < 0)	{
	    (void)PerlIO_close(fp);
	    RETPUSHUNDEF;
	}
	PerlIO_binmode(aTHX_ fp, '<', O_BINARY, NULL);
	len = PerlIO_read(fp, tbuf, sizeof(tbuf));
	(void)PerlIO_close(fp);
	if (len <= 0) {
	    if (S_ISDIR(PL_statcache.st_mode) && PL_op->op_type == OP_FTTEXT)
		RETPUSHNO;		/* special case NFS directories */
	    RETPUSHYES;		/* null file is anything */
	}
	s = tbuf;
    }

    /* now scan s to look for textiness */
    /*   XXX ASCII dependent code */

#if defined(DOSISH) || defined(USEMYBINMODE)
    /* ignore trailing ^Z on short files */
    if (len && len < (I32)sizeof(tbuf) && tbuf[len-1] == 26)
	--len;
#endif

    for (i = 0; i < len; i++, s++) {
	if (!*s) {			/* null never allowed in text */
	    odd += len;
	    break;
	}
#ifdef EBCDIC
        else if (!(isPRINT(*s) || isSPACE(*s)))
            odd++;
#else
	else if (*s & 128) {
#ifdef USE_LOCALE
	    if (IN_LOCALE_RUNTIME && isALPHA_LC(*s))
		continue;
#endif
	    /* utf8 characters don't count as odd */
	    if (UTF8_IS_START(*s)) {
		int ulen = UTF8SKIP(s);
		if (ulen < len - i) {
		    int j;
		    for (j = 1; j < ulen; j++) {
			if (!UTF8_IS_CONTINUATION(s[j]))
			    goto not_utf8;
		    }
		    --ulen;	/* loop does extra increment */
		    s += ulen;
		    i += ulen;
		    continue;
		}
	    }
	  not_utf8:
	    odd++;
	}
	else if (*s < 32 &&
	  *s != '\n' && *s != '\r' && *s != '\b' &&
	  *s != '\t' && *s != '\f' && *s != 27)
	    odd++;
#endif
    }

    if ((odd * 3 > len) == (PL_op->op_type == OP_FTTEXT)) /* allow 1/3 odd */
	RETPUSHNO;
    else
	RETPUSHYES;
}

/* File calls. */

PP(pp_chdir)
{
    dVAR; dSP; dTARGET;
    const char *tmps = NULL;
    GV *gv = NULL;

    if( MAXARG == 1 ) {
	SV * const sv = POPs;
	if (PL_op->op_flags & OPf_SPECIAL) {
	    gv = gv_fetchsv(sv, 0, SVt_PVIO);
	}
        else if (isGV_with_GP(sv)) {
	    gv = MUTABLE_GV(sv);
        }
	else if (SvROK(sv) && isGV_with_GP(SvRV(sv))) {
            gv = MUTABLE_GV(SvRV(sv));
        }
        else {
	    tmps = SvPV_nolen_const(sv);
	}
    }

    if( !gv && (!tmps || !*tmps) ) {
	HV * const table = GvHVn(PL_envgv);
	SV **svp;

        if (    (svp = hv_fetchs(table, "HOME", FALSE))
             || (svp = hv_fetchs(table, "LOGDIR", FALSE))
#ifdef VMS
             || (svp = hv_fetchs(table, "SYS$LOGIN", FALSE))
#endif
           )
        {
            if( MAXARG == 1 )
                deprecate("chdir('') or chdir(undef) as chdir()");
            tmps = SvPV_nolen_const(*svp);
        }
        else {
            PUSHi(0);
            TAINT_PROPER("chdir");
            RETURN;
        }
    }

    TAINT_PROPER("chdir");
    if (gv) {
#ifdef HAS_FCHDIR
	IO* const io = GvIO(gv);
	if (io) {
	    if (IoDIRP(io)) {
		PUSHi(fchdir(my_dirfd(IoDIRP(io))) >= 0);
	    } else if (IoIFP(io)) {
                PUSHi(fchdir(PerlIO_fileno(IoIFP(io))) >= 0);
	    }
	    else {
		if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
		    report_evil_fh(gv, io, PL_op->op_type);
		SETERRNO(EBADF, RMS_IFI);
		PUSHi(0);
	    }
        }
	else {
	    if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
		report_evil_fh(gv, io, PL_op->op_type);
	    SETERRNO(EBADF,RMS_IFI);
	    PUSHi(0);
	}
#else
	DIE(aTHX_ PL_no_func, "fchdir");
#endif
    }
    else 
        PUSHi( PerlDir_chdir(tmps) >= 0 );
#ifdef VMS
    /* Clear the DEFAULT element of ENV so we'll get the new value
     * in the future. */
    hv_delete(GvHVn(PL_envgv),"DEFAULT",7,G_DISCARD);
#endif
    RETURN;
}

PP(pp_chown)
{
    dVAR; dSP; dMARK; dTARGET;
    const I32 value = (I32)apply(PL_op->op_type, MARK, SP);

    SP = MARK;
    XPUSHi(value);
    RETURN;
}

PP(pp_chroot)
{
#ifdef HAS_CHROOT
    dVAR; dSP; dTARGET;
    char * const tmps = POPpx;
    TAINT_PROPER("chroot");
    PUSHi( chroot(tmps) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "chroot");
#endif
}

PP(pp_rename)
{
    dVAR; dSP; dTARGET;
    int anum;
    const char * const tmps2 = POPpconstx;
    const char * const tmps = SvPV_nolen_const(TOPs);
    TAINT_PROPER("rename");
#ifdef HAS_RENAME
    anum = PerlLIO_rename(tmps, tmps2);
#else
    if (!(anum = PerlLIO_stat(tmps, &PL_statbuf))) {
	if (same_dirent(tmps2, tmps))	/* can always rename to same name */
	    anum = 1;
	else {
	    if (PL_euid || PerlLIO_stat(tmps2, &PL_statbuf) < 0 || !S_ISDIR(PL_statbuf.st_mode))
		(void)UNLINK(tmps2);
	    if (!(anum = link(tmps, tmps2)))
		anum = UNLINK(tmps);
	}
    }
#endif
    SETi( anum >= 0 );
    RETURN;
}

#if defined(HAS_LINK) || defined(HAS_SYMLINK)
PP(pp_link)
{
    dVAR; dSP; dTARGET;
    const int op_type = PL_op->op_type;
    int result;

#  ifndef HAS_LINK
    if (op_type == OP_LINK)
	DIE(aTHX_ PL_no_func, "link");
#  endif
#  ifndef HAS_SYMLINK
    if (op_type == OP_SYMLINK)
	DIE(aTHX_ PL_no_func, "symlink");
#  endif

    {
	const char * const tmps2 = POPpconstx;
	const char * const tmps = SvPV_nolen_const(TOPs);
	TAINT_PROPER(PL_op_desc[op_type]);
	result =
#  if defined(HAS_LINK)
#    if defined(HAS_SYMLINK)
	    /* Both present - need to choose which.  */
	    (op_type == OP_LINK) ?
	    PerlLIO_link(tmps, tmps2) : symlink(tmps, tmps2);
#    else
    /* Only have link, so calls to pp_symlink will have DIE()d above.  */
	PerlLIO_link(tmps, tmps2);
#    endif
#  else
#    if defined(HAS_SYMLINK)
    /* Only have symlink, so calls to pp_link will have DIE()d above.  */
	symlink(tmps, tmps2);
#    endif
#  endif
    }

    SETi( result >= 0 );
    RETURN;
}
#else
PP(pp_link)
{
    /* Have neither.  */
    DIE(aTHX_ PL_no_func, PL_op_desc[PL_op->op_type]);
}
#endif

PP(pp_readlink)
{
    dVAR;
    dSP;
#ifdef HAS_SYMLINK
    dTARGET;
    const char *tmps;
    char buf[MAXPATHLEN];
    int len;

#ifndef INCOMPLETE_TAINTS
    TAINT;
#endif
    tmps = POPpconstx;
    len = readlink(tmps, buf, sizeof(buf) - 1);
    if (len < 0)
	RETPUSHUNDEF;
    PUSHp(buf, len);
    RETURN;
#else
    EXTEND(SP, 1);
    RETSETUNDEF;		/* just pretend it's a normal file */
#endif
}

#if !defined(HAS_MKDIR) || !defined(HAS_RMDIR)
STATIC int
S_dooneliner(pTHX_ const char *cmd, const char *filename)
{
    char * const save_filename = filename;
    char *cmdline;
    char *s;
    PerlIO *myfp;
    int anum = 1;
    Size_t size = strlen(cmd) + (strlen(filename) * 2) + 10;

    PERL_ARGS_ASSERT_DOONELINER;

    Newx(cmdline, size, char);
    my_strlcpy(cmdline, cmd, size);
    my_strlcat(cmdline, " ", size);
    for (s = cmdline + strlen(cmdline); *filename; ) {
	*s++ = '\\';
	*s++ = *filename++;
    }
    if (s - cmdline < size)
	my_strlcpy(s, " 2>&1", size - (s - cmdline));
    myfp = PerlProc_popen(cmdline, "r");
    Safefree(cmdline);

    if (myfp) {
	SV * const tmpsv = sv_newmortal();
	/* Need to save/restore 'PL_rs' ?? */
	s = sv_gets(tmpsv, myfp, 0);
	(void)PerlProc_pclose(myfp);
	if (s != NULL) {
	    int e;
	    for (e = 1;
#ifdef HAS_SYS_ERRLIST
		 e <= sys_nerr
#endif
		 ; e++)
	    {
		/* you don't see this */
		const char * const errmsg =
#ifdef HAS_SYS_ERRLIST
		    sys_errlist[e]
#else
		    strerror(e)
#endif
		    ;
		if (!errmsg)
		    break;
		if (instr(s, errmsg)) {
		    SETERRNO(e,0);
		    return 0;
		}
	    }
	    SETERRNO(0,0);
#ifndef EACCES
#define EACCES EPERM
#endif
	    if (instr(s, "cannot make"))
		SETERRNO(EEXIST,RMS_FEX);
	    else if (instr(s, "existing file"))
		SETERRNO(EEXIST,RMS_FEX);
	    else if (instr(s, "ile exists"))
		SETERRNO(EEXIST,RMS_FEX);
	    else if (instr(s, "non-exist"))
		SETERRNO(ENOENT,RMS_FNF);
	    else if (instr(s, "does not exist"))
		SETERRNO(ENOENT,RMS_FNF);
	    else if (instr(s, "not empty"))
		SETERRNO(EBUSY,SS_DEVOFFLINE);
	    else if (instr(s, "cannot access"))
		SETERRNO(EACCES,RMS_PRV);
	    else
		SETERRNO(EPERM,RMS_PRV);
	    return 0;
	}
	else {	/* some mkdirs return no failure indication */
	    anum = (PerlLIO_stat(save_filename, &PL_statbuf) >= 0);
	    if (PL_op->op_type == OP_RMDIR)
		anum = !anum;
	    if (anum)
		SETERRNO(0,0);
	    else
		SETERRNO(EACCES,RMS_PRV);	/* a guess */
	}
	return anum;
    }
    else
	return 0;
}
#endif

/* This macro removes trailing slashes from a directory name.
 * Different operating and file systems take differently to
 * trailing slashes.  According to POSIX 1003.1 1996 Edition
 * any number of trailing slashes should be allowed.
 * Thusly we snip them away so that even non-conforming
 * systems are happy.
 * We should probably do this "filtering" for all
 * the functions that expect (potentially) directory names:
 * -d, chdir(), chmod(), chown(), chroot(), fcntl()?,
 * (mkdir()), opendir(), rename(), rmdir(), stat(). --jhi */

#define TRIMSLASHES(tmps,len,copy) (tmps) = SvPV_const(TOPs, (len)); \
    if ((len) > 1 && (tmps)[(len)-1] == '/') { \
	do { \
	    (len)--; \
	} while ((len) > 1 && (tmps)[(len)-1] == '/'); \
	(tmps) = savepvn((tmps), (len)); \
	(copy) = TRUE; \
    }

PP(pp_mkdir)
{
    dVAR; dSP; dTARGET;
    STRLEN len;
    const char *tmps;
    bool copy = FALSE;
    const int mode = (MAXARG > 1) ? POPi : 0777;

    TRIMSLASHES(tmps,len,copy);

    TAINT_PROPER("mkdir");
#ifdef HAS_MKDIR
    SETi( PerlDir_mkdir(tmps, mode) >= 0 );
#else
    {
    int oldumask;
    SETi( dooneliner("mkdir", tmps) );
    oldumask = PerlLIO_umask(0);
    PerlLIO_umask(oldumask);
    PerlLIO_chmod(tmps, (mode & ~oldumask) & 0777);
    }
#endif
    if (copy)
	Safefree(tmps);
    RETURN;
}

PP(pp_rmdir)
{
    dVAR; dSP; dTARGET;
    STRLEN len;
    const char *tmps;
    bool copy = FALSE;

    TRIMSLASHES(tmps,len,copy);
    TAINT_PROPER("rmdir");
#ifdef HAS_RMDIR
    SETi( PerlDir_rmdir(tmps) >= 0 );
#else
    SETi( dooneliner("rmdir", tmps) );
#endif
    if (copy)
	Safefree(tmps);
    RETURN;
}

/* Directory calls. */

PP(pp_open_dir)
{
#if defined(Direntry_t) && defined(HAS_READDIR)
    dVAR; dSP;
    const char * const dirname = POPpconstx;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io)
	goto nope;

    if ((IoIFP(io) || IoOFP(io)))
	Perl_ck_warner_d(aTHX_ packWARN2(WARN_IO, WARN_DEPRECATED),
			 "Opening filehandle %s also as a directory",
			 GvENAME(gv));
    if (IoDIRP(io))
	PerlDir_close(IoDIRP(io));
    if (!(IoDIRP(io) = PerlDir_open(dirname)))
	goto nope;

    RETPUSHYES;
nope:
    if (!errno)
	SETERRNO(EBADF,RMS_DIR);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "opendir");
#endif
}

PP(pp_readdir)
{
#if !defined(Direntry_t) || !defined(HAS_READDIR)
    DIE(aTHX_ PL_no_dir_func, "readdir");
#else
#if !defined(I_DIRENT) && !defined(VMS)
    Direntry_t *readdir (DIR *);
#endif
    dVAR;
    dSP;

    SV *sv;
    const I32 gimme = GIMME;
    GV * const gv = MUTABLE_GV(POPs);
    register const Direntry_t *dp;
    register IO * const io = GvIOn(gv);

    if (!io || !IoDIRP(io)) {
	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
		       "readdir() attempted on invalid dirhandle %s", GvENAME(gv));
        goto nope;
    }

    do {
        dp = (Direntry_t *)PerlDir_read(IoDIRP(io));
        if (!dp)
            break;
#ifdef DIRNAMLEN
        sv = newSVpvn(dp->d_name, dp->d_namlen);
#else
        sv = newSVpv(dp->d_name, 0);
#endif
#ifndef INCOMPLETE_TAINTS
        if (!(IoFLAGS(io) & IOf_UNTAINT))
            SvTAINTED_on(sv);
#endif
        mXPUSHs(sv);
    } while (gimme == G_ARRAY);

    if (!dp && gimme != G_ARRAY)
        goto nope;

    RETURN;

nope:
    if (!errno)
	SETERRNO(EBADF,RMS_ISI);
    if (GIMME == G_ARRAY)
	RETURN;
    else
	RETPUSHUNDEF;
#endif
}

PP(pp_telldir)
{
#if defined(HAS_TELLDIR) || defined(telldir)
    dVAR; dSP; dTARGET;
 /* XXX does _anyone_ need this? --AD 2/20/1998 */
 /* XXX netbsd still seemed to.
    XXX HAS_TELLDIR_PROTO is new style, NEED_TELLDIR_PROTO is old style.
    --JHI 1999-Feb-02 */
# if !defined(HAS_TELLDIR_PROTO) || defined(NEED_TELLDIR_PROTO)
    long telldir (DIR *);
# endif
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io || !IoDIRP(io)) {
	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
		       "telldir() attempted on invalid dirhandle %s", GvENAME(gv));
        goto nope;
    }

    PUSHi( PerlDir_tell(IoDIRP(io)) );
    RETURN;
nope:
    if (!errno)
	SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "telldir");
#endif
}

PP(pp_seekdir)
{
#if defined(HAS_SEEKDIR) || defined(seekdir)
    dVAR; dSP;
    const long along = POPl;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io || !IoDIRP(io)) {
	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
		       "seekdir() attempted on invalid dirhandle %s", GvENAME(gv));
        goto nope;
    }
    (void)PerlDir_seek(IoDIRP(io), along);

    RETPUSHYES;
nope:
    if (!errno)
	SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "seekdir");
#endif
}

PP(pp_rewinddir)
{
#if defined(HAS_REWINDDIR) || defined(rewinddir)
    dVAR; dSP;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io || !IoDIRP(io)) {
	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
		       "rewinddir() attempted on invalid dirhandle %s", GvENAME(gv));
	goto nope;
    }
    (void)PerlDir_rewind(IoDIRP(io));
    RETPUSHYES;
nope:
    if (!errno)
	SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "rewinddir");
#endif
}

PP(pp_closedir)
{
#if defined(Direntry_t) && defined(HAS_READDIR)
    dVAR; dSP;
    GV * const gv = MUTABLE_GV(POPs);
    register IO * const io = GvIOn(gv);

    if (!io || !IoDIRP(io)) {
	Perl_ck_warner(aTHX_ packWARN(WARN_IO),
		       "closedir() attempted on invalid dirhandle %s", GvENAME(gv));
        goto nope;
    }
#ifdef VOID_CLOSEDIR
    PerlDir_close(IoDIRP(io));
#else
    if (PerlDir_close(IoDIRP(io)) < 0) {
	IoDIRP(io) = 0; /* Don't try to close again--coredumps on SysV */
	goto nope;
    }
#endif
    IoDIRP(io) = 0;

    RETPUSHYES;
nope:
    if (!errno)
	SETERRNO(EBADF,RMS_IFI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "closedir");
#endif
}

/* Process control. */

PP(pp_fork)
{
#ifdef HAS_FORK
    dVAR; dSP; dTARGET;
    Pid_t childpid;

    EXTEND(SP, 1);
    PERL_FLUSHALL_FOR_CHILD;
    childpid = PerlProc_fork();
    if (childpid < 0)
	RETSETUNDEF;
    if (!childpid) {
	GV * const tmpgv = gv_fetchpvs("$", GV_ADD|GV_NOTQUAL, SVt_PV);
	if (tmpgv) {
            SvREADONLY_off(GvSV(tmpgv));
	    sv_setiv(GvSV(tmpgv), (IV)PerlProc_getpid());
            SvREADONLY_on(GvSV(tmpgv));
        }
#ifdef THREADS_HAVE_PIDS
	PL_ppid = (IV)getppid();
#endif
#ifdef PERL_USES_PL_PIDSTATUS
	hv_clear(PL_pidstatus);	/* no kids, so don't wait for 'em */
#endif
    }
    PUSHi(childpid);
    RETURN;
#else
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    dSP; dTARGET;
    Pid_t childpid;

    EXTEND(SP, 1);
    PERL_FLUSHALL_FOR_CHILD;
    childpid = PerlProc_fork();
    if (childpid == -1)
	RETSETUNDEF;
    PUSHi(childpid);
    RETURN;
#  else
    DIE(aTHX_ PL_no_func, "fork");
#  endif
#endif
}

PP(pp_wait)
{
#if (!defined(DOSISH) || defined(OS2) || defined(WIN32)) && !defined(__LIBCATAMOUNT__)
    dVAR; dSP; dTARGET;
    Pid_t childpid;
    int argflags;

    if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
        childpid = wait4pid(-1, &argflags, 0);
    else {
        while ((childpid = wait4pid(-1, &argflags, 0)) == -1 &&
	       errno == EINTR) {
	  PERL_ASYNC_CHECK();
	}
    }
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    /* 0 and -1 are both error returns (the former applies to WNOHANG case) */
    STATUS_NATIVE_CHILD_SET((childpid && childpid != -1) ? argflags : -1);
#  else
    STATUS_NATIVE_CHILD_SET((childpid > 0) ? argflags : -1);
#  endif
    XPUSHi(childpid);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "wait");
#endif
}

PP(pp_waitpid)
{
#if (!defined(DOSISH) || defined(OS2) || defined(WIN32)) && !defined(__LIBCATAMOUNT__)
    dVAR; dSP; dTARGET;
    const int optype = POPi;
    const Pid_t pid = TOPi;
    Pid_t result;
    int argflags;

    if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
        result = wait4pid(pid, &argflags, optype);
    else {
        while ((result = wait4pid(pid, &argflags, optype)) == -1 &&
	       errno == EINTR) {
	  PERL_ASYNC_CHECK();
	}
    }
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    /* 0 and -1 are both error returns (the former applies to WNOHANG case) */
    STATUS_NATIVE_CHILD_SET((result && result != -1) ? argflags : -1);
#  else
    STATUS_NATIVE_CHILD_SET((result > 0) ? argflags : -1);
#  endif
    SETi(result);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "waitpid");
#endif
}

PP(pp_system)
{
    dVAR; dSP; dMARK; dORIGMARK; dTARGET;
#if defined(__LIBCATAMOUNT__)
    PL_statusvalue = -1;
    SP = ORIGMARK;
    XPUSHi(-1);
#else
    I32 value;
    int result;

    if (PL_tainting) {
	TAINT_ENV();
	while (++MARK <= SP) {
	    (void)SvPV_nolen_const(*MARK);      /* stringify for taint check */
	    if (PL_tainted)
		break;
	}
	MARK = ORIGMARK;
	TAINT_PROPER("system");
    }
    PERL_FLUSHALL_FOR_CHILD;
#if (defined(HAS_FORK) || defined(AMIGAOS)) && !defined(VMS) && !defined(OS2) || defined(PERL_MICRO)
    {
	Pid_t childpid;
	int pp[2];
	I32 did_pipes = 0;

	if (PerlProc_pipe(pp) >= 0)
	    did_pipes = 1;
	while ((childpid = PerlProc_fork()) == -1) {
	    if (errno != EAGAIN) {
		value = -1;
		SP = ORIGMARK;
		XPUSHi(value);
		if (did_pipes) {
		    PerlLIO_close(pp[0]);
		    PerlLIO_close(pp[1]);
		}
		RETURN;
	    }
	    sleep(5);
	}
	if (childpid > 0) {
	    Sigsave_t ihand,qhand; /* place to save signals during system() */
	    int status;

	    if (did_pipes)
		PerlLIO_close(pp[1]);
#ifndef PERL_MICRO
	    rsignal_save(SIGINT,  (Sighandler_t) SIG_IGN, &ihand);
	    rsignal_save(SIGQUIT, (Sighandler_t) SIG_IGN, &qhand);
#endif
	    do {
		result = wait4pid(childpid, &status, 0);
	    } while (result == -1 && errno == EINTR);
#ifndef PERL_MICRO
	    (void)rsignal_restore(SIGINT, &ihand);
	    (void)rsignal_restore(SIGQUIT, &qhand);
#endif
	    STATUS_NATIVE_CHILD_SET(result == -1 ? -1 : status);
	    do_execfree();	/* free any memory child malloced on fork */
	    SP = ORIGMARK;
	    if (did_pipes) {
		int errkid;
		unsigned n = 0;
		SSize_t n1;

		while (n < sizeof(int)) {
		    n1 = PerlLIO_read(pp[0],
				      (void*)(((char*)&errkid)+n),
				      (sizeof(int)) - n);
		    if (n1 <= 0)
			break;
		    n += n1;
		}
		PerlLIO_close(pp[0]);
		if (n) {			/* Error */
		    if (n != sizeof(int))
			DIE(aTHX_ "panic: kid popen errno read");
		    errno = errkid;		/* Propagate errno from kid */
		    STATUS_NATIVE_CHILD_SET(-1);
		}
	    }
	    XPUSHi(STATUS_CURRENT);
	    RETURN;
	}
	if (did_pipes) {
	    PerlLIO_close(pp[0]);
#if defined(HAS_FCNTL) && defined(F_SETFD)
	    fcntl(pp[1], F_SETFD, FD_CLOEXEC);
#endif
	}
	if (PL_op->op_flags & OPf_STACKED) {
	    SV * const really = *++MARK;
	    value = (I32)do_aexec5(really, MARK, SP, pp[1], did_pipes);
	}
	else if (SP - MARK != 1)
	    value = (I32)do_aexec5(NULL, MARK, SP, pp[1], did_pipes);
	else {
	    value = (I32)do_exec3(SvPVx_nolen(sv_mortalcopy(*SP)), pp[1], did_pipes);
	}
	PerlProc__exit(-1);
    }
#else /* ! FORK or VMS or OS/2 */
    PL_statusvalue = 0;
    result = 0;
    if (PL_op->op_flags & OPf_STACKED) {
	SV * const really = *++MARK;
#  if defined(WIN32) || defined(OS2) || defined(__SYMBIAN32__) || defined(__VMS)
	value = (I32)do_aspawn(really, MARK, SP);
#  else
	value = (I32)do_aspawn(really, (void **)MARK, (void **)SP);
#  endif
    }
    else if (SP - MARK != 1) {
#  if defined(WIN32) || defined(OS2) || defined(__SYMBIAN32__) || defined(__VMS)
	value = (I32)do_aspawn(NULL, MARK, SP);
#  else
	value = (I32)do_aspawn(NULL, (void **)MARK, (void **)SP);
#  endif
    }
    else {
	value = (I32)do_spawn(SvPVx_nolen(sv_mortalcopy(*SP)));
    }
    if (PL_statusvalue == -1)	/* hint that value must be returned as is */
	result = 1;
    STATUS_NATIVE_CHILD_SET(value);
    do_execfree();
    SP = ORIGMARK;
    XPUSHi(result ? value : STATUS_CURRENT);
#endif /* !FORK or VMS or OS/2 */
#endif
    RETURN;
}

PP(pp_exec)
{
    dVAR; dSP; dMARK; dORIGMARK; dTARGET;
    I32 value;

    if (PL_tainting) {
	TAINT_ENV();
	while (++MARK <= SP) {
	    (void)SvPV_nolen_const(*MARK);      /* stringify for taint check */
	    if (PL_tainted)
		break;
	}
	MARK = ORIGMARK;
	TAINT_PROPER("exec");
    }
    PERL_FLUSHALL_FOR_CHILD;
    if (PL_op->op_flags & OPf_STACKED) {
	SV * const really = *++MARK;
	value = (I32)do_aexec(really, MARK, SP);
    }
    else if (SP - MARK != 1)
#ifdef VMS
	value = (I32)vms_do_aexec(NULL, MARK, SP);
#else
#  ifdef __OPEN_VM
	{
	   (void ) do_aspawn(NULL, MARK, SP);
	   value = 0;
	}
#  else
	value = (I32)do_aexec(NULL, MARK, SP);
#  endif
#endif
    else {
#ifdef VMS
	value = (I32)vms_do_exec(SvPVx_nolen(sv_mortalcopy(*SP)));
#else
#  ifdef __OPEN_VM
	(void) do_spawn(SvPVx_nolen(sv_mortalcopy(*SP)));
	value = 0;
#  else
	value = (I32)do_exec(SvPVx_nolen(sv_mortalcopy(*SP)));
#  endif
#endif
    }

    SP = ORIGMARK;
    XPUSHi(value);
    RETURN;
}

PP(pp_getppid)
{
#ifdef HAS_GETPPID
    dVAR; dSP; dTARGET;
#   ifdef THREADS_HAVE_PIDS
    if (PL_ppid != 1 && getppid() == 1)
	/* maybe the parent process has died. Refresh ppid cache */
	PL_ppid = 1;
    XPUSHi( PL_ppid );
#   else
    XPUSHi( getppid() );
#   endif
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getppid");
#endif
}

PP(pp_getpgrp)
{
#ifdef HAS_GETPGRP
    dVAR; dSP; dTARGET;
    Pid_t pgrp;
    const Pid_t pid = (MAXARG < 1) ? 0 : SvIVx(POPs);

#ifdef BSD_GETPGRP
    pgrp = (I32)BSD_GETPGRP(pid);
#else
    if (pid != 0 && pid != PerlProc_getpid())
	DIE(aTHX_ "POSIX getpgrp can't take an argument");
    pgrp = getpgrp();
#endif
    XPUSHi(pgrp);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getpgrp()");
#endif
}

PP(pp_setpgrp)
{
#ifdef HAS_SETPGRP
    dVAR; dSP; dTARGET;
    Pid_t pgrp;
    Pid_t pid;
    if (MAXARG < 2) {
	pgrp = 0;
	pid = 0;
	XPUSHi(-1);
    }
    else {
	pgrp = POPi;
	pid = TOPi;
    }

    TAINT_PROPER("setpgrp");
#ifdef BSD_SETPGRP
    SETi( BSD_SETPGRP(pid, pgrp) >= 0 );
#else
    if ((pgrp != 0 && pgrp != PerlProc_getpid())
	|| (pid != 0 && pid != PerlProc_getpid()))
    {
	DIE(aTHX_ "setpgrp can't take arguments");
    }
    SETi( setpgrp() >= 0 );
#endif /* USE_BSDPGRP */
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "setpgrp()");
#endif
}

PP(pp_getpriority)
{
#ifdef HAS_GETPRIORITY
    dVAR; dSP; dTARGET;
    const int who = POPi;
    const int which = TOPi;
    SETi( getpriority(which, who) );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getpriority()");
#endif
}

PP(pp_setpriority)
{
#ifdef HAS_SETPRIORITY
    dVAR; dSP; dTARGET;
    const int niceval = POPi;
    const int who = POPi;
    const int which = TOPi;
    TAINT_PROPER("setpriority");
    SETi( setpriority(which, who, niceval) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "setpriority()");
#endif
}

/* Time calls. */

PP(pp_time)
{
    dVAR; dSP; dTARGET;
#ifdef BIG_TIME
    XPUSHn( time(NULL) );
#else
    XPUSHi( time(NULL) );
#endif
    RETURN;
}

PP(pp_tms)
{
#ifdef HAS_TIMES
    dVAR;
    dSP;
    EXTEND(SP, 4);
#ifndef VMS
    (void)PerlProc_times(&PL_timesbuf);
#else
    (void)PerlProc_times((tbuffer_t *)&PL_timesbuf);  /* time.h uses different name for */
                                                   /* struct tms, though same data   */
                                                   /* is returned.                   */
#endif

    mPUSHn(((NV)PL_timesbuf.tms_utime)/(NV)PL_clocktick);
    if (GIMME == G_ARRAY) {
	mPUSHn(((NV)PL_timesbuf.tms_stime)/(NV)PL_clocktick);
	mPUSHn(((NV)PL_timesbuf.tms_cutime)/(NV)PL_clocktick);
	mPUSHn(((NV)PL_timesbuf.tms_cstime)/(NV)PL_clocktick);
    }
    RETURN;
#else
#   ifdef PERL_MICRO
    dSP;
    mPUSHn(0.0);
    EXTEND(SP, 4);
    if (GIMME == G_ARRAY) {
	 mPUSHn(0.0);
	 mPUSHn(0.0);
	 mPUSHn(0.0);
    }
    RETURN;
#   else
    DIE(aTHX_ "times not implemented");
#   endif
#endif /* HAS_TIMES */
}

/* The 32 bit int year limits the times we can represent to these
   boundaries with a few days wiggle room to account for time zone
   offsets
*/
/* Sat Jan  3 00:00:00 -2147481748 */
#define TIME_LOWER_BOUND -67768100567755200.0
/* Sun Dec 29 12:00:00  2147483647 */
#define TIME_UPPER_BOUND  67767976233316800.0

PP(pp_gmtime)
{
    dVAR;
    dSP;
    Time64_T when;
    struct TM tmbuf;
    struct TM *err;
    const char *opname = PL_op->op_type == OP_LOCALTIME ? "localtime" : "gmtime";
    static const char * const dayname[] =
	{"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
    static const char * const monname[] =
	{"Jan", "Feb", "Mar", "Apr", "May", "Jun",
	 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

    if (MAXARG < 1) {
	time_t now;
	(void)time(&now);
	when = (Time64_T)now;
    }
    else {
	NV input = Perl_floor(POPn);
	when = (Time64_T)input;
	if (when != input) {
	    Perl_ck_warner(aTHX_ packWARN(WARN_OVERFLOW),
			   "%s(%.0" NVff ") too large", opname, input);
	}
    }

    if ( TIME_LOWER_BOUND > when ) {
	Perl_ck_warner(aTHX_ packWARN(WARN_OVERFLOW),
		       "%s(%.0" NVff ") too small", opname, when);
	err = NULL;
    }
    else if( when > TIME_UPPER_BOUND ) {
	Perl_ck_warner(aTHX_ packWARN(WARN_OVERFLOW),
		       "%s(%.0" NVff ") too large", opname, when);
	err = NULL;
    }
    else {
	if (PL_op->op_type == OP_LOCALTIME)
	    err = S_localtime64_r(&when, &tmbuf);
	else
	    err = S_gmtime64_r(&when, &tmbuf);
    }

    if (err == NULL) {
	/* XXX %lld broken for quads */
	Perl_ck_warner(aTHX_ packWARN(WARN_OVERFLOW),
		       "%s(%.0" NVff ") failed", opname, when);
    }

    if (GIMME != G_ARRAY) {	/* scalar context */
	SV *tsv;
	/* XXX newSVpvf()'s %lld type is broken, so cheat with a double */
	double year = (double)tmbuf.tm_year + 1900;

        EXTEND(SP, 1);
        EXTEND_MORTAL(1);
	if (err == NULL)
	    RETPUSHUNDEF;

	tsv = Perl_newSVpvf(aTHX_ "%s %s %2d %02d:%02d:%02d %.0f",
			    dayname[tmbuf.tm_wday],
			    monname[tmbuf.tm_mon],
			    tmbuf.tm_mday,
			    tmbuf.tm_hour,
			    tmbuf.tm_min,
			    tmbuf.tm_sec,
			    year);
	mPUSHs(tsv);
    }
    else {			/* list context */
	if ( err == NULL )
	    RETURN;

        EXTEND(SP, 9);
        EXTEND_MORTAL(9);
        mPUSHi(tmbuf.tm_sec);
	mPUSHi(tmbuf.tm_min);
	mPUSHi(tmbuf.tm_hour);
	mPUSHi(tmbuf.tm_mday);
	mPUSHi(tmbuf.tm_mon);
	mPUSHn(tmbuf.tm_year);
	mPUSHi(tmbuf.tm_wday);
	mPUSHi(tmbuf.tm_yday);
	mPUSHi(tmbuf.tm_isdst);
    }
    RETURN;
}

PP(pp_alarm)
{
#ifdef HAS_ALARM
    dVAR; dSP; dTARGET;
    int anum;
    anum = POPi;
    anum = alarm((unsigned int)anum);
    if (anum < 0)
	RETPUSHUNDEF;
    PUSHi(anum);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "alarm");
#endif
}

PP(pp_sleep)
{
    dVAR; dSP; dTARGET;
    I32 duration;
    Time_t lasttime;
    Time_t when;

    (void)time(&lasttime);
    if (MAXARG < 1)
	PerlProc_pause();
    else {
	duration = POPi;
	PerlProc_sleep((unsigned int)duration);
    }
    (void)time(&when);
    XPUSHi(when - lasttime);
    RETURN;
}

/* Shared memory. */
/* Merged with some message passing. */

PP(pp_shmwrite)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dVAR; dSP; dMARK; dTARGET;
    const int op_type = PL_op->op_type;
    I32 value;

    switch (op_type) {
    case OP_MSGSND:
	value = (I32)(do_msgsnd(MARK, SP) >= 0);
	break;
    case OP_MSGRCV:
	value = (I32)(do_msgrcv(MARK, SP) >= 0);
	break;
    case OP_SEMOP:
	value = (I32)(do_semop(MARK, SP) >= 0);
	break;
    default:
	value = (I32)(do_shmio(op_type, MARK, SP) >= 0);
	break;
    }

    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    return pp_semget();
#endif
}

/* Semaphores. */

PP(pp_semget)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dVAR; dSP; dMARK; dTARGET;
    const int anum = do_ipcget(PL_op->op_type, MARK, SP);
    SP = MARK;
    if (anum == -1)
	RETPUSHUNDEF;
    PUSHi(anum);
    RETURN;
#else
    DIE(aTHX_ "System V IPC is not implemented on this machine");
#endif
}

PP(pp_semctl)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dVAR; dSP; dMARK; dTARGET;
    const int anum = do_ipcctl(PL_op->op_type, MARK, SP);
    SP = MARK;
    if (anum == -1)
	RETSETUNDEF;
    if (anum != 0) {
	PUSHi(anum);
    }
    else {
	PUSHp(zero_but_true, ZBTLEN);
    }
    RETURN;
#else
    return pp_semget();
#endif
}

/* I can't const this further without getting warnings about the types of
   various arrays passed in from structures.  */
static SV *
S_space_join_names_mortal(pTHX_ char *const *array)
{
    SV *target;

    PERL_ARGS_ASSERT_SPACE_JOIN_NAMES_MORTAL;

    if (array && *array) {
	target = newSVpvs_flags("", SVs_TEMP);
	while (1) {
	    sv_catpv(target, *array);
	    if (!*++array)
		break;
	    sv_catpvs(target, " ");
	}
    } else {
	target = sv_mortalcopy(&PL_sv_no);
    }
    return target;
}

/* Get system info. */

PP(pp_ghostent)
{
#if defined(HAS_GETHOSTBYNAME) || defined(HAS_GETHOSTBYADDR) || defined(HAS_GETHOSTENT)
    dVAR; dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
#ifndef HAS_GETHOST_PROTOS /* XXX Do we need individual probes? */
    struct hostent *gethostbyaddr(Netdb_host_t, Netdb_hlen_t, int);
    struct hostent *gethostbyname(Netdb_name_t);
    struct hostent *gethostent(void);
#endif
    struct hostent *hent = NULL;
    unsigned long len;

    EXTEND(SP, 10);
    if (which == OP_GHBYNAME) {
#ifdef HAS_GETHOSTBYNAME
	const char* const name = POPpbytex;
	hent = PerlSock_gethostbyname(name);
#else
	DIE(aTHX_ PL_no_sock_func, "gethostbyname");
#endif
    }
    else if (which == OP_GHBYADDR) {
#ifdef HAS_GETHOSTBYADDR
	const int addrtype = POPi;
	SV * const addrsv = POPs;
	STRLEN addrlen;
	const char *addr = (char *)SvPVbyte(addrsv, addrlen);

	hent = PerlSock_gethostbyaddr(addr, (Netdb_hlen_t) addrlen, addrtype);
#else
	DIE(aTHX_ PL_no_sock_func, "gethostbyaddr");
#endif
    }
    else
#ifdef HAS_GETHOSTENT
	hent = PerlSock_gethostent();
#else
	DIE(aTHX_ PL_no_sock_func, "gethostent");
#endif

#ifdef HOST_NOT_FOUND
	if (!hent) {
#ifdef USE_REENTRANT_API
#   ifdef USE_GETHOSTENT_ERRNO
	    h_errno = PL_reentrant_buffer->_gethostent_errno;
#   endif
#endif
	    STATUS_UNIX_SET(h_errno);
	}
#endif

    if (GIMME != G_ARRAY) {
	PUSHs(sv = sv_newmortal());
	if (hent) {
	    if (which == OP_GHBYNAME) {
		if (hent->h_addr)
		    sv_setpvn(sv, hent->h_addr, hent->h_length);
	    }
	    else
		sv_setpv(sv, (char*)hent->h_name);
	}
	RETURN;
    }

    if (hent) {
	mPUSHs(newSVpv((char*)hent->h_name, 0));
	PUSHs(space_join_names_mortal(hent->h_aliases));
	mPUSHi(hent->h_addrtype);
	len = hent->h_length;
	mPUSHi(len);
#ifdef h_addr
	for (elem = hent->h_addr_list; elem && *elem; elem++) {
	    mXPUSHp(*elem, len);
	}
#else
	if (hent->h_addr)
	    mPUSHp(hent->h_addr, len);
	else
	    PUSHs(sv_mortalcopy(&PL_sv_no));
#endif /* h_addr */
    }
    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "gethostent");
#endif
}

PP(pp_gnetent)
{
#if defined(HAS_GETNETBYNAME) || defined(HAS_GETNETBYADDR) || defined(HAS_GETNETENT)
    dVAR; dSP;
    I32 which = PL_op->op_type;
    register SV *sv;
#ifndef HAS_GETNET_PROTOS /* XXX Do we need individual probes? */
    struct netent *getnetbyaddr(Netdb_net_t, int);
    struct netent *getnetbyname(Netdb_name_t);
    struct netent *getnetent(void);
#endif
    struct netent *nent;

    if (which == OP_GNBYNAME){
#ifdef HAS_GETNETBYNAME
	const char * const name = POPpbytex;
	nent = PerlSock_getnetbyname(name);
#else
        DIE(aTHX_ PL_no_sock_func, "getnetbyname");
#endif
    }
    else if (which == OP_GNBYADDR) {
#ifdef HAS_GETNETBYADDR
	const int addrtype = POPi;
	const Netdb_net_t addr = (Netdb_net_t) (U32)POPu;
	nent = PerlSock_getnetbyaddr(addr, addrtype);
#else
	DIE(aTHX_ PL_no_sock_func, "getnetbyaddr");
#endif
    }
    else
#ifdef HAS_GETNETENT
	nent = PerlSock_getnetent();
#else
        DIE(aTHX_ PL_no_sock_func, "getnetent");
#endif

#ifdef HOST_NOT_FOUND
	if (!nent) {
#ifdef USE_REENTRANT_API
#   ifdef USE_GETNETENT_ERRNO
	     h_errno = PL_reentrant_buffer->_getnetent_errno;
#   endif
#endif
	    STATUS_UNIX_SET(h_errno);
	}
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
	PUSHs(sv = sv_newmortal());
	if (nent) {
	    if (which == OP_GNBYNAME)
		sv_setiv(sv, (IV)nent->n_net);
	    else
		sv_setpv(sv, nent->n_name);
	}
	RETURN;
    }

    if (nent) {
	mPUSHs(newSVpv(nent->n_name, 0));
	PUSHs(space_join_names_mortal(nent->n_aliases));
	mPUSHi(nent->n_addrtype);
	mPUSHi(nent->n_net);
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getnetent");
#endif
}

PP(pp_gprotoent)
{
#if defined(HAS_GETPROTOBYNAME) || defined(HAS_GETPROTOBYNUMBER) || defined(HAS_GETPROTOENT)
    dVAR; dSP;
    I32 which = PL_op->op_type;
    register SV *sv;
#ifndef HAS_GETPROTO_PROTOS /* XXX Do we need individual probes? */
    struct protoent *getprotobyname(Netdb_name_t);
    struct protoent *getprotobynumber(int);
    struct protoent *getprotoent(void);
#endif
    struct protoent *pent;

    if (which == OP_GPBYNAME) {
#ifdef HAS_GETPROTOBYNAME
	const char* const name = POPpbytex;
	pent = PerlSock_getprotobyname(name);
#else
	DIE(aTHX_ PL_no_sock_func, "getprotobyname");
#endif
    }
    else if (which == OP_GPBYNUMBER) {
#ifdef HAS_GETPROTOBYNUMBER
	const int number = POPi;
	pent = PerlSock_getprotobynumber(number);
#else
	DIE(aTHX_ PL_no_sock_func, "getprotobynumber");
#endif
    }
    else
#ifdef HAS_GETPROTOENT
	pent = PerlSock_getprotoent();
#else
	DIE(aTHX_ PL_no_sock_func, "getprotoent");
#endif

    EXTEND(SP, 3);
    if (GIMME != G_ARRAY) {
	PUSHs(sv = sv_newmortal());
	if (pent) {
	    if (which == OP_GPBYNAME)
		sv_setiv(sv, (IV)pent->p_proto);
	    else
		sv_setpv(sv, pent->p_name);
	}
	RETURN;
    }

    if (pent) {
	mPUSHs(newSVpv(pent->p_name, 0));
	PUSHs(space_join_names_mortal(pent->p_aliases));
	mPUSHi(pent->p_proto);
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getprotoent");
#endif
}

PP(pp_gservent)
{
#if defined(HAS_GETSERVBYNAME) || defined(HAS_GETSERVBYPORT) || defined(HAS_GETSERVENT)
    dVAR; dSP;
    I32 which = PL_op->op_type;
    register SV *sv;
#ifndef HAS_GETSERV_PROTOS /* XXX Do we need individual probes? */
    struct servent *getservbyname(Netdb_name_t, Netdb_name_t);
    struct servent *getservbyport(int, Netdb_name_t);
    struct servent *getservent(void);
#endif
    struct servent *sent;

    if (which == OP_GSBYNAME) {
#ifdef HAS_GETSERVBYNAME
	const char * const proto = POPpbytex;
	const char * const name = POPpbytex;
	sent = PerlSock_getservbyname(name, (proto && !*proto) ? NULL : proto);
#else
	DIE(aTHX_ PL_no_sock_func, "getservbyname");
#endif
    }
    else if (which == OP_GSBYPORT) {
#ifdef HAS_GETSERVBYPORT
	const char * const proto = POPpbytex;
	unsigned short port = (unsigned short)POPu;
#ifdef HAS_HTONS
	port = PerlSock_htons(port);
#endif
	sent = PerlSock_getservbyport(port, (proto && !*proto) ? NULL : proto);
#else
	DIE(aTHX_ PL_no_sock_func, "getservbyport");
#endif
    }
    else
#ifdef HAS_GETSERVENT
	sent = PerlSock_getservent();
#else
	DIE(aTHX_ PL_no_sock_func, "getservent");
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
	PUSHs(sv = sv_newmortal());
	if (sent) {
	    if (which == OP_GSBYNAME) {
#ifdef HAS_NTOHS
		sv_setiv(sv, (IV)PerlSock_ntohs(sent->s_port));
#else
		sv_setiv(sv, (IV)(sent->s_port));
#endif
	    }
	    else
		sv_setpv(sv, sent->s_name);
	}
	RETURN;
    }

    if (sent) {
	mPUSHs(newSVpv(sent->s_name, 0));
	PUSHs(space_join_names_mortal(sent->s_aliases));
#ifdef HAS_NTOHS
	mPUSHi(PerlSock_ntohs(sent->s_port));
#else
	mPUSHi(sent->s_port);
#endif
	mPUSHs(newSVpv(sent->s_proto, 0));
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getservent");
#endif
}

PP(pp_shostent)
{
#ifdef HAS_SETHOSTENT
    dVAR; dSP;
    PerlSock_sethostent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "sethostent");
#endif
}

PP(pp_snetent)
{
#ifdef HAS_SETNETENT
    dVAR; dSP;
    (void)PerlSock_setnetent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setnetent");
#endif
}

PP(pp_sprotoent)
{
#ifdef HAS_SETPROTOENT
    dVAR; dSP;
    (void)PerlSock_setprotoent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setprotoent");
#endif
}

PP(pp_sservent)
{
#ifdef HAS_SETSERVENT
    dVAR; dSP;
    (void)PerlSock_setservent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setservent");
#endif
}

PP(pp_ehostent)
{
#ifdef HAS_ENDHOSTENT
    dVAR; dSP;
    PerlSock_endhostent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endhostent");
#endif
}

PP(pp_enetent)
{
#ifdef HAS_ENDNETENT
    dVAR; dSP;
    PerlSock_endnetent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endnetent");
#endif
}

PP(pp_eprotoent)
{
#ifdef HAS_ENDPROTOENT
    dVAR; dSP;
    PerlSock_endprotoent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endprotoent");
#endif
}

PP(pp_eservent)
{
#ifdef HAS_ENDSERVENT
    dVAR; dSP;
    PerlSock_endservent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endservent");
#endif
}

PP(pp_gpwent)
{
#ifdef HAS_PASSWD
    dVAR; dSP;
    I32 which = PL_op->op_type;
    register SV *sv;
    struct passwd *pwent  = NULL;
    /*
     * We currently support only the SysV getsp* shadow password interface.
     * The interface is declared in <shadow.h> and often one needs to link
     * with -lsecurity or some such.
     * This interface is used at least by Solaris, HP-UX, IRIX, and Linux.
     * (and SCO?)
     *
     * AIX getpwnam() is clever enough to return the encrypted password
     * only if the caller (euid?) is root.
     *
     * There are at least three other shadow password APIs.  Many platforms
     * seem to contain more than one interface for accessing the shadow
     * password databases, possibly for compatibility reasons.
     * The getsp*() is by far he simplest one, the other two interfaces
     * are much more complicated, but also very similar to each other.
     *
     * <sys/types.h>
     * <sys/security.h>
     * <prot.h>
     * struct pr_passwd *getprpw*();
     * The password is in
     * char getprpw*(...).ufld.fd_encrypt[]
     * Mention HAS_GETPRPWNAM here so that Configure probes for it.
     *
     * <sys/types.h>
     * <sys/security.h>
     * <prot.h>
     * struct es_passwd *getespw*();
     * The password is in
     * char *(getespw*(...).ufld.fd_encrypt)
     * Mention HAS_GETESPWNAM here so that Configure probes for it.
     *
     * <userpw.h> (AIX)
     * struct userpw *getuserpw();
     * The password is in
     * char *(getuserpw(...)).spw_upw_passwd
     * (but the de facto standard getpwnam() should work okay)
     *
     * Mention I_PROT here so that Configure probes for it.
     *
     * In HP-UX for getprpw*() the manual page claims that one should include
     * <hpsecurity.h> instead of <sys/security.h>, but that is not needed
     * if one includes <shadow.h> as that includes <hpsecurity.h>,
     * and pp_sys.c already includes <shadow.h> if there is such.
     *
     * Note that <sys/security.h> is already probed for, but currently
     * it is only included in special cases.
     *
     * In Digital UNIX/Tru64 if using the getespw*() (which seems to be
     * be preferred interface, even though also the getprpw*() interface
     * is available) one needs to link with -lsecurity -ldb -laud -lm.
     * One also needs to call set_auth_parameters() in main() before
     * doing anything else, whether one is using getespw*() or getprpw*().
     *
     * Note that accessing the shadow databases can be magnitudes
     * slower than accessing the standard databases.
     *
     * --jhi
     */

#   if defined(__CYGWIN__) && defined(USE_REENTRANT_API)
    /* Cygwin 1.5.3-1 has buggy getpwnam_r() and getpwuid_r():
     * the pw_comment is left uninitialized. */
    PL_reentrant_buffer->_pwent_struct.pw_comment = NULL;
#   endif

    switch (which) {
    case OP_GPWNAM:
      {
	const char* const name = POPpbytex;
	pwent  = getpwnam(name);
      }
      break;
    case OP_GPWUID:
      {
	Uid_t uid = POPi;
	pwent = getpwuid(uid);
      }
	break;
    case OP_GPWENT:
#   ifdef HAS_GETPWENT
	pwent  = getpwent();
#ifdef POSIX_BC   /* In some cases pw_passwd has invalid addresses */
	if (pwent) pwent = getpwnam(pwent->pw_name);
#endif
#   else
	DIE(aTHX_ PL_no_func, "getpwent");
#   endif
	break;
    }

    EXTEND(SP, 10);
    if (GIMME != G_ARRAY) {
	PUSHs(sv = sv_newmortal());
	if (pwent) {
	    if (which == OP_GPWNAM)
#   if Uid_t_sign <= 0
		sv_setiv(sv, (IV)pwent->pw_uid);
#   else
		sv_setuv(sv, (UV)pwent->pw_uid);
#   endif
	    else
		sv_setpv(sv, pwent->pw_name);
	}
	RETURN;
    }

    if (pwent) {
	mPUSHs(newSVpv(pwent->pw_name, 0));

	sv = newSViv(0);
	mPUSHs(sv);
	/* If we have getspnam(), we try to dig up the shadow
	 * password.  If we are underprivileged, the shadow
	 * interface will set the errno to EACCES or similar,
	 * and return a null pointer.  If this happens, we will
	 * use the dummy password (usually "*" or "x") from the
	 * standard password database.
	 *
	 * In theory we could skip the shadow call completely
	 * if euid != 0 but in practice we cannot know which
	 * security measures are guarding the shadow databases
	 * on a random platform.
	 *
	 * Resist the urge to use additional shadow interfaces.
	 * Divert the urge to writing an extension instead.
	 *
	 * --jhi */
	/* Some AIX setups falsely(?) detect some getspnam(), which
	 * has a different API than the Solaris/IRIX one. */
#   if defined(HAS_GETSPNAM) && !defined(_AIX)
	{
	    dSAVE_ERRNO;
	    const struct spwd * const spwent = getspnam(pwent->pw_name);
			  /* Save and restore errno so that
			   * underprivileged attempts seem
			   * to have never made the unsccessful
			   * attempt to retrieve the shadow password. */
	    RESTORE_ERRNO;
	    if (spwent && spwent->sp_pwdp)
		sv_setpv(sv, spwent->sp_pwdp);
	}
#   endif
#   ifdef PWPASSWD
	if (!SvPOK(sv)) /* Use the standard password, then. */
	    sv_setpv(sv, pwent->pw_passwd);
#   endif

#   ifndef INCOMPLETE_TAINTS
	/* passwd is tainted because user himself can diddle with it.
	 * admittedly not much and in a very limited way, but nevertheless. */
	SvTAINTED_on(sv);
#   endif

#   if Uid_t_sign <= 0
	mPUSHi(pwent->pw_uid);
#   else
	mPUSHu(pwent->pw_uid);
#   endif

#   if Uid_t_sign <= 0
	mPUSHi(pwent->pw_gid);
#   else
	mPUSHu(pwent->pw_gid);
#   endif
	/* pw_change, pw_quota, and pw_age are mutually exclusive--
	 * because of the poor interface of the Perl getpw*(),
	 * not because there's some standard/convention saying so.
	 * A better interface would have been to return a hash,
	 * but we are accursed by our history, alas. --jhi.  */
#   ifdef PWCHANGE
	mPUSHi(pwent->pw_change);
#   else
#       ifdef PWQUOTA
	mPUSHi(pwent->pw_quota);
#       else
#           ifdef PWAGE
	mPUSHs(newSVpv(pwent->pw_age, 0));
#	    else
	/* I think that you can never get this compiled, but just in case.  */
	PUSHs(sv_mortalcopy(&PL_sv_no));
#           endif
#       endif
#   endif

	/* pw_class and pw_comment are mutually exclusive--.
	 * see the above note for pw_change, pw_quota, and pw_age. */
#   ifdef PWCLASS
	mPUSHs(newSVpv(pwent->pw_class, 0));
#   else
#       ifdef PWCOMMENT
	mPUSHs(newSVpv(pwent->pw_comment, 0));
#	else
	/* I think that you can never get this compiled, but just in case.  */
	PUSHs(sv_mortalcopy(&PL_sv_no));
#       endif
#   endif

#   ifdef PWGECOS
	PUSHs(sv = sv_2mortal(newSVpv(pwent->pw_gecos, 0)));
#   else
	PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   endif
#   ifndef INCOMPLETE_TAINTS
	/* pw_gecos is tainted because user himself can diddle with it. */
	SvTAINTED_on(sv);
#   endif

	mPUSHs(newSVpv(pwent->pw_dir, 0));

	PUSHs(sv = sv_2mortal(newSVpv(pwent->pw_shell, 0)));
#   ifndef INCOMPLETE_TAINTS
	/* pw_shell is tainted because user himself can diddle with it. */
	SvTAINTED_on(sv);
#   endif

#   ifdef PWEXPIRE
	mPUSHi(pwent->pw_expire);
#   endif
    }
    RETURN;
#else
    DIE(aTHX_ PL_no_func, PL_op_desc[PL_op->op_type]);
#endif
}

PP(pp_spwent)
{
#if defined(HAS_PASSWD) && defined(HAS_SETPWENT)
    dVAR; dSP;
    setpwent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "setpwent");
#endif
}

PP(pp_epwent)
{
#if defined(HAS_PASSWD) && defined(HAS_ENDPWENT)
    dVAR; dSP;
    endpwent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "endpwent");
#endif
}

PP(pp_ggrent)
{
#ifdef HAS_GROUP
    dVAR; dSP;
    const I32 which = PL_op->op_type;
    const struct group *grent;

    if (which == OP_GGRNAM) {
	const char* const name = POPpbytex;
	grent = (const struct group *)getgrnam(name);
    }
    else if (which == OP_GGRGID) {
	const Gid_t gid = POPi;
	grent = (const struct group *)getgrgid(gid);
    }
    else
#ifdef HAS_GETGRENT
	grent = (struct group *)getgrent();
#else
        DIE(aTHX_ PL_no_func, "getgrent");
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
	SV * const sv = sv_newmortal();

	PUSHs(sv);
	if (grent) {
	    if (which == OP_GGRNAM)
#if Gid_t_sign <= 0
		sv_setiv(sv, (IV)grent->gr_gid);
#else
		sv_setuv(sv, (UV)grent->gr_gid);
#endif
	    else
		sv_setpv(sv, grent->gr_name);
	}
	RETURN;
    }

    if (grent) {
	mPUSHs(newSVpv(grent->gr_name, 0));

#ifdef GRPASSWD
	mPUSHs(newSVpv(grent->gr_passwd, 0));
#else
	PUSHs(sv_mortalcopy(&PL_sv_no));
#endif

#if Gid_t_sign <= 0
	mPUSHi(grent->gr_gid);
#else
	mPUSHu(grent->gr_gid);
#endif

#if !(defined(_CRAYMPP) && defined(USE_REENTRANT_API))
	/* In UNICOS/mk (_CRAYMPP) the multithreading
	 * versions (getgrnam_r, getgrgid_r)
	 * seem to return an illegal pointer
	 * as the group members list, gr_mem.
	 * getgrent() doesn't even have a _r version
	 * but the gr_mem is poisonous anyway.
	 * So yes, you cannot get the list of group
	 * members if building multithreaded in UNICOS/mk. */
	PUSHs(space_join_names_mortal(grent->gr_mem));
#endif
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_func, PL_op_desc[PL_op->op_type]);
#endif
}

PP(pp_sgrent)
{
#if defined(HAS_GROUP) && defined(HAS_SETGRENT)
    dVAR; dSP;
    setgrent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "setgrent");
#endif
}

PP(pp_egrent)
{
#if defined(HAS_GROUP) && defined(HAS_ENDGRENT)
    dVAR; dSP;
    endgrent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "endgrent");
#endif
}

PP(pp_getlogin)
{
#ifdef HAS_GETLOGIN
    dVAR; dSP; dTARGET;
    char *tmps;
    EXTEND(SP, 1);
    if (!(tmps = PerlProc_getlogin()))
	RETPUSHUNDEF;
    PUSHp(tmps, strlen(tmps));
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getlogin");
#endif
}

/* Miscellaneous. */

PP(pp_syscall)
{
#ifdef HAS_SYSCALL
    dVAR; dSP; dMARK; dORIGMARK; dTARGET;
    register I32 items = SP - MARK;
    unsigned long a[20];
    register I32 i = 0;
    I32 retval = -1;

    if (PL_tainting) {
	while (++MARK <= SP) {
	    if (SvTAINTED(*MARK)) {
		TAINT;
		break;
	    }
	}
	MARK = ORIGMARK;
	TAINT_PROPER("syscall");
    }

    /* This probably won't work on machines where sizeof(long) != sizeof(int)
     * or where sizeof(long) != sizeof(char*).  But such machines will
     * not likely have syscall implemented either, so who cares?
     */
    while (++MARK <= SP) {
	if (SvNIOK(*MARK) || !i)
	    a[i++] = SvIV(*MARK);
	else if (*MARK == &PL_sv_undef)
	    a[i++] = 0;
	else
	    a[i++] = (unsigned long)SvPV_force_nolen(*MARK);
	if (i > 15)
	    break;
    }
    switch (items) {
    default:
	DIE(aTHX_ "Too many args to syscall");
    case 0:
	DIE(aTHX_ "Too few args to syscall");
    case 1:
	retval = syscall(a[0]);
	break;
    case 2:
	retval = syscall(a[0],a[1]);
	break;
    case 3:
	retval = syscall(a[0],a[1],a[2]);
	break;
    case 4:
	retval = syscall(a[0],a[1],a[2],a[3]);
	break;
    case 5:
	retval = syscall(a[0],a[1],a[2],a[3],a[4]);
	break;
    case 6:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5]);
	break;
    case 7:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6]);
	break;
    case 8:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7]);
	break;
#ifdef atarist
    case 9:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8]);
	break;
    case 10:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9]);
	break;
    case 11:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
	  a[10]);
	break;
    case 12:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
	  a[10],a[11]);
	break;
    case 13:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
	  a[10],a[11],a[12]);
	break;
    case 14:
	retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
	  a[10],a[11],a[12],a[13]);
	break;
#endif /* atarist */
    }
    SP = ORIGMARK;
    PUSHi(retval);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "syscall");
#endif
}

#ifdef FCNTL_EMULATE_FLOCK

/*  XXX Emulate flock() with fcntl().
    What's really needed is a good file locking module.
*/

static int
fcntl_emulate_flock(int fd, int operation)
{
    int res;
    struct flock flock;

    switch (operation & ~LOCK_NB) {
    case LOCK_SH:
	flock.l_type = F_RDLCK;
	break;
    case LOCK_EX:
	flock.l_type = F_WRLCK;
	break;
    case LOCK_UN:
	flock.l_type = F_UNLCK;
	break;
    default:
	errno = EINVAL;
	return -1;
    }
    flock.l_whence = SEEK_SET;
    flock.l_start = flock.l_len = (Off_t)0;

    res = fcntl(fd, (operation & LOCK_NB) ? F_SETLK : F_SETLKW, &flock);
    if (res == -1 && ((errno == EAGAIN) || (errno == EACCES)))
	errno = EWOULDBLOCK;
    return res;
}

#endif /* FCNTL_EMULATE_FLOCK */

#ifdef LOCKF_EMULATE_FLOCK

/*  XXX Emulate flock() with lockf().  This is just to increase
    portability of scripts.  The calls are not completely
    interchangeable.  What's really needed is a good file
    locking module.
*/

/*  The lockf() constants might have been defined in <unistd.h>.
    Unfortunately, <unistd.h> causes troubles on some mixed
    (BSD/POSIX) systems, such as SunOS 4.1.3.

   Further, the lockf() constants aren't POSIX, so they might not be
   visible if we're compiling with _POSIX_SOURCE defined.  Thus, we'll
   just stick in the SVID values and be done with it.  Sigh.
*/

# ifndef F_ULOCK
#  define F_ULOCK	0	/* Unlock a previously locked region */
# endif
# ifndef F_LOCK
#  define F_LOCK	1	/* Lock a region for exclusive use */
# endif
# ifndef F_TLOCK
#  define F_TLOCK	2	/* Test and lock a region for exclusive use */
# endif
# ifndef F_TEST
#  define F_TEST	3	/* Test a region for other processes locks */
# endif

static int
lockf_emulate_flock(int fd, int operation)
{
    int i;
    Off_t pos;
    dSAVE_ERRNO;

    /* flock locks entire file so for lockf we need to do the same	*/
    pos = PerlLIO_lseek(fd, (Off_t)0, SEEK_CUR);    /* get pos to restore later */
    if (pos > 0)	/* is seekable and needs to be repositioned	*/
	if (PerlLIO_lseek(fd, (Off_t)0, SEEK_SET) < 0)
	    pos = -1;	/* seek failed, so don't seek back afterwards	*/
    RESTORE_ERRNO;

    switch (operation) {

	/* LOCK_SH - get a shared lock */
	case LOCK_SH:
	/* LOCK_EX - get an exclusive lock */
	case LOCK_EX:
	    i = lockf (fd, F_LOCK, 0);
	    break;

	/* LOCK_SH|LOCK_NB - get a non-blocking shared lock */
	case LOCK_SH|LOCK_NB:
	/* LOCK_EX|LOCK_NB - get a non-blocking exclusive lock */
	case LOCK_EX|LOCK_NB:
	    i = lockf (fd, F_TLOCK, 0);
	    if (i == -1)
		if ((errno == EAGAIN) || (errno == EACCES))
		    errno = EWOULDBLOCK;
	    break;

	/* LOCK_UN - unlock (non-blocking is a no-op) */
	case LOCK_UN:
	case LOCK_UN|LOCK_NB:
	    i = lockf (fd, F_ULOCK, 0);
	    break;

	/* Default - can't decipher operation */
	default:
	    i = -1;
	    errno = EINVAL;
	    break;
    }

    if (pos > 0)      /* need to restore position of the handle	*/
	PerlLIO_lseek(fd, pos, SEEK_SET);	/* ignore error here	*/

    return (i);
}

#endif /* LOCKF_EMULATE_FLOCK */

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 *
 * ex: set ts=8 sts=4 sw=4 noet:
 */