[perl5.git] / perl.c

/*    perl.c
 *
 *    Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 2003, 2004, 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.
 *
 */

/*
 * "A ship then new they built for him/of mithril and of elven glass" --Bilbo
 */

/* This file contains the top-level functions that are used to create, use
 * and destroy a perl interpreter, plus the functions used by XS code to
 * call back into perl. Note that it does not contain the actual main()
 * function of the interpreter; that can be found in perlmain.c
 */

/* PSz 12 Nov 03
 * 
 * Be proud that perl(1) may proclaim:
 *   Setuid Perl scripts are safer than C programs ...
 * Do not abandon (deprecate) suidperl. Do not advocate C wrappers.
 * 
 * The flow was: perl starts, notices script is suid, execs suidperl with same
 * arguments; suidperl opens script, checks many things, sets itself with
 * right UID, execs perl with similar arguments but with script pre-opened on
 * /dev/fd/xxx; perl checks script is as should be and does work. This was
 * insecure: see perlsec(1) for many problems with this approach.
 * 
 * The "correct" flow should be: perl starts, opens script and notices it is
 * suid, checks many things, execs suidperl with similar arguments but with
 * script on /dev/fd/xxx; suidperl checks script and /dev/fd/xxx object are
 * same, checks arguments match #! line, sets itself with right UID, execs
 * perl with same arguments; perl checks many things and does work.
 * 
 * (Opening the script in perl instead of suidperl, we "lose" scripts that
 * are readable to the target UID but not to the invoker. Where did
 * unreadable scripts work anyway?)
 * 
 * For now, suidperl and perl are pretty much the same large and cumbersome
 * program, so suidperl can check its argument list (see comments elsewhere).
 * 
 * References:
 * Original bug report:
 *   http://bugs.perl.org/index.html?req=bug_id&bug_id=20010322.218
 *   http://rt.perl.org/rt2/Ticket/Display.html?id=6511
 * Comments and discussion with Debian:
 *   http://bugs.debian.org/203426
 *   http://bugs.debian.org/220486
 * Debian Security Advisory DSA 431-1 (does not fully fix problem):
 *   http://www.debian.org/security/2004/dsa-431
 * CVE candidate:
 *   http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0618
 * Previous versions of this patch sent to perl5-porters:
 *   http://www.mail-archive.com/perl5-porters@perl.org/msg71953.html
 *   http://www.mail-archive.com/perl5-porters@perl.org/msg75245.html
 *   http://www.mail-archive.com/perl5-porters@perl.org/msg75563.html
 *   http://www.mail-archive.com/perl5-porters@perl.org/msg75635.html
 * 
Paul Szabo - psz@maths.usyd.edu.au  http://www.maths.usyd.edu.au:8000/u/psz/
School of Mathematics and Statistics  University of Sydney   2006  Australia
 * 
 */
/* PSz 13 Nov 03
 * Use truthful, neat, specific error messages.
 * Cannot always hide the truth; security must not depend on doing so.
 */

/* PSz 18 Feb 04
 * Use global(?), thread-local fdscript for easier checks.
 * (I do not understand how we could possibly get a thread race:
 * do not all threads go through the same initialization? Or in
 * fact, are not threads started only after we get the script and
 * so know what to do? Oh well, make things super-safe...)
 */

#include "EXTERN.h"
#define PERL_IN_PERL_C
#include "perl.h"
#include "patchlevel.h"			/* for local_patches */

#ifdef NETWARE
#include "nwutil.h"	
char *nw_get_sitelib(const char *pl);
#endif

/* XXX If this causes problems, set i_unistd=undef in the hint file.  */
#ifdef I_UNISTD
#include <unistd.h>
#endif

#ifdef __BEOS__
#  define HZ 1000000
#endif

#ifndef HZ
#  ifdef CLK_TCK
#    define HZ CLK_TCK
#  else
#    define HZ 60
#  endif
#endif

#if !defined(STANDARD_C) && !defined(HAS_GETENV_PROTOTYPE) && !defined(PERL_MICRO)
char *getenv (char *); /* Usually in <stdlib.h> */
#endif

static I32 read_e_script(pTHX_ int idx, SV *buf_sv, int maxlen);

#ifdef IAMSUID
#ifndef DOSUID
#define DOSUID
#endif
#endif /* IAMSUID */

#ifdef SETUID_SCRIPTS_ARE_SECURE_NOW
#ifdef DOSUID
#undef DOSUID
#endif
#endif

#if defined(USE_ITHREADS)
#  define INIT_TLS_AND_INTERP \
    STMT_START {				\
	if (!PL_curinterp) {			\
	    PERL_SET_INTERP(my_perl);		\
	    INIT_THREADS;			\
	    ALLOC_THREAD_KEY;			\
	    PERL_SET_THX(my_perl);		\
	    OP_REFCNT_INIT;			\
	    MUTEX_INIT(&PL_dollarzero_mutex);	\
	}					\
	else {					\
	    PERL_SET_THX(my_perl);		\
	}					\
    } STMT_END
#else
#  define INIT_TLS_AND_INTERP \
    STMT_START {				\
	if (!PL_curinterp) {			\
	    PERL_SET_INTERP(my_perl);		\
	}					\
	PERL_SET_THX(my_perl);			\
    } STMT_END
#  endif

#ifdef PERL_IMPLICIT_SYS
PerlInterpreter *
perl_alloc_using(struct IPerlMem* ipM, struct IPerlMem* ipMS,
		 struct IPerlMem* ipMP, struct IPerlEnv* ipE,
		 struct IPerlStdIO* ipStd, struct IPerlLIO* ipLIO,
		 struct IPerlDir* ipD, struct IPerlSock* ipS,
		 struct IPerlProc* ipP)
{
    PerlInterpreter *my_perl;
    /* New() needs interpreter, so call malloc() instead */
    my_perl = (PerlInterpreter*)(*ipM->pMalloc)(ipM, sizeof(PerlInterpreter));
    INIT_TLS_AND_INTERP;
    Zero(my_perl, 1, PerlInterpreter);
    PL_Mem = ipM;
    PL_MemShared = ipMS;
    PL_MemParse = ipMP;
    PL_Env = ipE;
    PL_StdIO = ipStd;
    PL_LIO = ipLIO;
    PL_Dir = ipD;
    PL_Sock = ipS;
    PL_Proc = ipP;

    return my_perl;
}
#else

/*
=head1 Embedding Functions

=for apidoc perl_alloc

Allocates a new Perl interpreter.  See L<perlembed>.

=cut
*/

PerlInterpreter *
perl_alloc(void)
{
    PerlInterpreter *my_perl;
#ifdef USE_5005THREADS
    dTHX;
#endif

    /* New() needs interpreter, so call malloc() instead */
    my_perl = (PerlInterpreter*)PerlMem_malloc(sizeof(PerlInterpreter));

    INIT_TLS_AND_INTERP;
    return ZeroD(my_perl, 1, PerlInterpreter);
}
#endif /* PERL_IMPLICIT_SYS */

/*
=for apidoc perl_construct

Initializes a new Perl interpreter.  See L<perlembed>.

=cut
*/

void
perl_construct(pTHXx)
{
#ifdef MULTIPLICITY
    init_interp();
    PL_perl_destruct_level = 1;
#else
   if (PL_perl_destruct_level > 0)
       init_interp();
#endif
   /* Init the real globals (and main thread)? */
    if (!PL_linestr) {
#ifdef PERL_FLEXIBLE_EXCEPTIONS
	PL_protect = MEMBER_TO_FPTR(Perl_default_protect); /* for exceptions */
#endif

	PL_curcop = &PL_compiling;	/* needed by ckWARN, right away */

	PL_linestr = NEWSV(65,79);
	sv_upgrade(PL_linestr,SVt_PVIV);

	if (!SvREADONLY(&PL_sv_undef)) {
	    /* set read-only and try to insure than we wont see REFCNT==0
	       very often */

	    SvREADONLY_on(&PL_sv_undef);
	    SvREFCNT(&PL_sv_undef) = (~(U32)0)/2;

	    sv_setpv(&PL_sv_no,PL_No);
	    /* value lookup in void context - happens to have the side effect
	       of caching the numeric forms.  */
	    SvIV(&PL_sv_no);
	    SvNV(&PL_sv_no);
	    SvREADONLY_on(&PL_sv_no);
	    SvREFCNT(&PL_sv_no) = (~(U32)0)/2;

	    sv_setpv(&PL_sv_yes,PL_Yes);
	    SvIV(&PL_sv_yes);
	    SvNV(&PL_sv_yes);
	    SvREADONLY_on(&PL_sv_yes);
	    SvREFCNT(&PL_sv_yes) = (~(U32)0)/2;

	    SvREADONLY_on(&PL_sv_placeholder);
	    SvREFCNT(&PL_sv_placeholder) = (~(U32)0)/2;
	}

	PL_sighandlerp = Perl_sighandler;
	PL_pidstatus = newHV();
    }

    PL_rs = newSVpvn("\n", 1);

    init_stacks();

    init_ids();
    PL_lex_state = LEX_NOTPARSING;

    JMPENV_BOOTSTRAP;
    STATUS_ALL_SUCCESS;

    init_i18nl10n(1);
    SET_NUMERIC_STANDARD();

#if defined(LOCAL_PATCH_COUNT)
    PL_localpatches = local_patches;	/* For possible -v */
#endif

#ifdef HAVE_INTERP_INTERN
    sys_intern_init();
#endif

    PerlIO_init(aTHX);			/* Hook to IO system */

    PL_fdpid = newAV();			/* for remembering popen pids by fd */
    PL_modglobal = newHV();		/* pointers to per-interpreter module globals */
    PL_errors = newSVpvn("",0);
    sv_setpvn(PERL_DEBUG_PAD(0), "", 0);	/* For regex debugging. */
    sv_setpvn(PERL_DEBUG_PAD(1), "", 0);	/* ext/re needs these */
    sv_setpvn(PERL_DEBUG_PAD(2), "", 0);	/* even without DEBUGGING. */
#ifdef USE_ITHREADS
    PL_regex_padav = newAV();
    av_push(PL_regex_padav,(SV*)newAV());    /* First entry is an array of empty elements */
    PL_regex_pad = AvARRAY(PL_regex_padav);
#endif
#ifdef USE_REENTRANT_API
    Perl_reentrant_init(aTHX);
#endif

    /* Note that strtab is a rather special HV.  Assumptions are made
       about not iterating on it, and not adding tie magic to it.
       It is properly deallocated in perl_destruct() */
    PL_strtab = newHV();

    HvSHAREKEYS_off(PL_strtab);			/* mandatory */
    hv_ksplit(PL_strtab, 512);

#if defined(__DYNAMIC__) && (defined(NeXT) || defined(__NeXT__))
    _dyld_lookup_and_bind
	("__environ", (unsigned long *) &environ_pointer, NULL);
#endif /* environ */

#ifndef PERL_MICRO
#   ifdef  USE_ENVIRON_ARRAY
    PL_origenviron = environ;
#   endif
#endif

    /* Use sysconf(_SC_CLK_TCK) if available, if not
     * available or if the sysconf() fails, use the HZ. */
#if defined(HAS_SYSCONF) && defined(_SC_CLK_TCK)
    PL_clocktick = sysconf(_SC_CLK_TCK);
    if (PL_clocktick <= 0)
#endif
	 PL_clocktick = HZ;

    PL_stashcache = newHV();

    PL_patchlevel = newSVpv(
	    Perl_form(aTHX_ "%d.%d.%d",
	    (int)PERL_REVISION,
	    (int)PERL_VERSION,
	    (int)PERL_SUBVERSION ), 0
    );

    ENTER;
}

/*
=for apidoc nothreadhook

Stub that provides thread hook for perl_destruct when there are
no threads.

=cut
*/

int
Perl_nothreadhook(pTHX)
{
    return 0;
}

/*
=for apidoc perl_destruct

Shuts down a Perl interpreter.  See L<perlembed>.

=cut
*/

int
perl_destruct(pTHXx)
{
    volatile int destruct_level;  /* 0=none, 1=full, 2=full with checks */
    HV *hv;
#ifdef USE_5005THREADS
    dTHX;
#endif /* USE_5005THREADS */

    /* wait for all pseudo-forked children to finish */
    PERL_WAIT_FOR_CHILDREN;

    destruct_level = PL_perl_destruct_level;
#ifdef DEBUGGING
    {
	char *s;
	if ((s = PerlEnv_getenv("PERL_DESTRUCT_LEVEL"))) {
	    int i = atoi(s);
	    if (destruct_level < i)
		destruct_level = i;
	}
    }
#endif


    if(PL_exit_flags & PERL_EXIT_DESTRUCT_END) {
        dJMPENV;
        int x = 0;

        JMPENV_PUSH(x);
        if (PL_endav && !PL_minus_c)
            call_list(PL_scopestack_ix, PL_endav);
        JMPENV_POP;
    }
    LEAVE;
    FREETMPS;

    /* Need to flush since END blocks can produce output */
    my_fflush_all();

    if (CALL_FPTR(PL_threadhook)(aTHX)) {
        /* Threads hook has vetoed further cleanup */
        return STATUS_NATIVE_EXPORT;
    }

    /* We must account for everything.  */

    /* Destroy the main CV and syntax tree */
    if (PL_main_root) {
	/* ensure comppad/curpad to refer to main's pad */
	if (CvPADLIST(PL_main_cv)) {
	    PAD_SET_CUR_NOSAVE(CvPADLIST(PL_main_cv), 1);
	}
	op_free(PL_main_root);
	PL_main_root = Nullop;
    }
    PL_curcop = &PL_compiling;
    PL_main_start = Nullop;
    SvREFCNT_dec(PL_main_cv);
    PL_main_cv = Nullcv;
    PL_dirty = TRUE;

    /* Tell PerlIO we are about to tear things apart in case
       we have layers which are using resources that should
       be cleaned up now.
     */

    PerlIO_destruct(aTHX);

    if (PL_sv_objcount) {
	/*
	 * Try to destruct global references.  We do this first so that the
	 * destructors and destructees still exist.  Some sv's might remain.
	 * Non-referenced objects are on their own.
	 */
	sv_clean_objs();
	PL_sv_objcount = 0;
    }

    /* unhook hooks which will soon be, or use, destroyed data */
    SvREFCNT_dec(PL_warnhook);
    PL_warnhook = Nullsv;
    SvREFCNT_dec(PL_diehook);
    PL_diehook = Nullsv;

    /* call exit list functions */
    while (PL_exitlistlen-- > 0)
	PL_exitlist[PL_exitlistlen].fn(aTHX_ PL_exitlist[PL_exitlistlen].ptr);

    Safefree(PL_exitlist);

    PL_exitlist = NULL;
    PL_exitlistlen = 0;

    if (destruct_level == 0){

	DEBUG_P(debprofdump());

#if defined(PERLIO_LAYERS)
	/* No more IO - including error messages ! */
	PerlIO_cleanup(aTHX);
#endif

	/* The exit() function will do everything that needs doing. */
        return STATUS_NATIVE_EXPORT;
    }

    /* jettison our possibly duplicated environment */
    /* if PERL_USE_SAFE_PUTENV is defined environ will not have been copied
     * so we certainly shouldn't free it here
     */
#ifndef PERL_MICRO
#if defined(USE_ENVIRON_ARRAY) && !defined(PERL_USE_SAFE_PUTENV)
    if (environ != PL_origenviron && !PL_use_safe_putenv
#ifdef USE_ITHREADS
	/* only main thread can free environ[0] contents */
	&& PL_curinterp == aTHX
#endif
	)
    {
	I32 i;

	for (i = 0; environ[i]; i++)
	    safesysfree(environ[i]);

	/* Must use safesysfree() when working with environ. */
	safesysfree(environ);		

	environ = PL_origenviron;
    }
#endif
#endif /* !PERL_MICRO */

    /* reset so print() ends up where we expect */
    setdefout(Nullgv);

#ifdef USE_ITHREADS
    /* the syntax tree is shared between clones
     * so op_free(PL_main_root) only ReREFCNT_dec's
     * REGEXPs in the parent interpreter
     * we need to manually ReREFCNT_dec for the clones
     */
    {
        I32 i = AvFILLp(PL_regex_padav) + 1;
        SV **ary = AvARRAY(PL_regex_padav);

        while (i) {
            SV *resv = ary[--i];
            REGEXP *re = INT2PTR(REGEXP *,SvIVX(resv));

            if (SvFLAGS(resv) & SVf_BREAK) {
                /* this is PL_reg_curpm, already freed
                 * flag is set in regexec.c:S_regtry
                 */
                SvFLAGS(resv) &= ~SVf_BREAK;
            }
	    else if(SvREPADTMP(resv)) {
	      SvREPADTMP_off(resv);
	    }
            else {
                ReREFCNT_dec(re);
            }
        }
    }
    SvREFCNT_dec(PL_regex_padav);
    PL_regex_padav = Nullav;
    PL_regex_pad = NULL;
#endif

    SvREFCNT_dec((SV*) PL_stashcache);
    PL_stashcache = NULL;

    /* loosen bonds of global variables */

    if(PL_rsfp) {
	(void)PerlIO_close(PL_rsfp);
	PL_rsfp = Nullfp;
    }

    /* Filters for program text */
    SvREFCNT_dec(PL_rsfp_filters);
    PL_rsfp_filters = Nullav;

    /* switches */
    PL_preprocess   = FALSE;
    PL_minus_n      = FALSE;
    PL_minus_p      = FALSE;
    PL_minus_l      = FALSE;
    PL_minus_a      = FALSE;
    PL_minus_F      = FALSE;
    PL_doswitches   = FALSE;
    PL_dowarn       = G_WARN_OFF;
    PL_doextract    = FALSE;
    PL_sawampersand = FALSE;	/* must save all match strings */
    PL_unsafe       = FALSE;

    Safefree(PL_inplace);
    PL_inplace = Nullch;
    SvREFCNT_dec(PL_patchlevel);

    if (PL_e_script) {
	SvREFCNT_dec(PL_e_script);
	PL_e_script = Nullsv;
    }

    PL_perldb = 0;

    /* magical thingies */

    SvREFCNT_dec(PL_ofs_sv);	/* $, */
    PL_ofs_sv = Nullsv;

    SvREFCNT_dec(PL_ors_sv);	/* $\ */
    PL_ors_sv = Nullsv;

    SvREFCNT_dec(PL_rs);	/* $/ */
    PL_rs = Nullsv;

    PL_multiline = 0;		/* $* */
    Safefree(PL_osname);	/* $^O */
    PL_osname = Nullch;

    SvREFCNT_dec(PL_statname);
    PL_statname = Nullsv;
    PL_statgv = Nullgv;

    /* defgv, aka *_ should be taken care of elsewhere */

    /* clean up after study() */
    SvREFCNT_dec(PL_lastscream);
    PL_lastscream = Nullsv;
    Safefree(PL_screamfirst);
    PL_screamfirst = 0;
    Safefree(PL_screamnext);
    PL_screamnext  = 0;

    /* float buffer */
    Safefree(PL_efloatbuf);
    PL_efloatbuf = Nullch;
    PL_efloatsize = 0;

    /* startup and shutdown function lists */
    SvREFCNT_dec(PL_beginav);
    SvREFCNT_dec(PL_beginav_save);
    SvREFCNT_dec(PL_endav);
    SvREFCNT_dec(PL_checkav);
    SvREFCNT_dec(PL_checkav_save);
    SvREFCNT_dec(PL_initav);
    PL_beginav = Nullav;
    PL_beginav_save = Nullav;
    PL_endav = Nullav;
    PL_checkav = Nullav;
    PL_checkav_save = Nullav;
    PL_initav = Nullav;

    /* shortcuts just get cleared */
    PL_envgv = Nullgv;
    PL_incgv = Nullgv;
    PL_hintgv = Nullgv;
    PL_errgv = Nullgv;
    PL_argvgv = Nullgv;
    PL_argvoutgv = Nullgv;
    PL_stdingv = Nullgv;
    PL_stderrgv = Nullgv;
    PL_last_in_gv = Nullgv;
    PL_replgv = Nullgv;
    PL_DBgv = Nullgv;
    PL_DBline = Nullgv;
    PL_DBsub = Nullgv;
    PL_DBsingle = Nullsv;
    PL_DBtrace = Nullsv;
    PL_DBsignal = Nullsv;
    PL_DBassertion = Nullsv;
    PL_DBcv = Nullcv;
    PL_dbargs = Nullav;
    PL_debstash = Nullhv;

    SvREFCNT_dec(PL_argvout_stack);
    PL_argvout_stack = Nullav;

    SvREFCNT_dec(PL_modglobal);
    PL_modglobal = Nullhv;
    SvREFCNT_dec(PL_preambleav);
    PL_preambleav = Nullav;
    SvREFCNT_dec(PL_subname);
    PL_subname = Nullsv;
    SvREFCNT_dec(PL_linestr);
    PL_linestr = Nullsv;
    SvREFCNT_dec(PL_pidstatus);
    PL_pidstatus = Nullhv;
    SvREFCNT_dec(PL_toptarget);
    PL_toptarget = Nullsv;
    SvREFCNT_dec(PL_bodytarget);
    PL_bodytarget = Nullsv;
    PL_formtarget = Nullsv;

    /* free locale stuff */
#ifdef USE_LOCALE_COLLATE
    Safefree(PL_collation_name);
    PL_collation_name = Nullch;
#endif

#ifdef USE_LOCALE_NUMERIC
    Safefree(PL_numeric_name);
    PL_numeric_name = Nullch;
    SvREFCNT_dec(PL_numeric_radix_sv);
    PL_numeric_radix_sv = Nullsv;
#endif

    /* clear utf8 character classes */
    SvREFCNT_dec(PL_utf8_alnum);
    SvREFCNT_dec(PL_utf8_alnumc);
    SvREFCNT_dec(PL_utf8_ascii);
    SvREFCNT_dec(PL_utf8_alpha);
    SvREFCNT_dec(PL_utf8_space);
    SvREFCNT_dec(PL_utf8_cntrl);
    SvREFCNT_dec(PL_utf8_graph);
    SvREFCNT_dec(PL_utf8_digit);
    SvREFCNT_dec(PL_utf8_upper);
    SvREFCNT_dec(PL_utf8_lower);
    SvREFCNT_dec(PL_utf8_print);
    SvREFCNT_dec(PL_utf8_punct);
    SvREFCNT_dec(PL_utf8_xdigit);
    SvREFCNT_dec(PL_utf8_mark);
    SvREFCNT_dec(PL_utf8_toupper);
    SvREFCNT_dec(PL_utf8_totitle);
    SvREFCNT_dec(PL_utf8_tolower);
    SvREFCNT_dec(PL_utf8_tofold);
    SvREFCNT_dec(PL_utf8_idstart);
    SvREFCNT_dec(PL_utf8_idcont);
    PL_utf8_alnum	= Nullsv;
    PL_utf8_alnumc	= Nullsv;
    PL_utf8_ascii	= Nullsv;
    PL_utf8_alpha	= Nullsv;
    PL_utf8_space	= Nullsv;
    PL_utf8_cntrl	= Nullsv;
    PL_utf8_graph	= Nullsv;
    PL_utf8_digit	= Nullsv;
    PL_utf8_upper	= Nullsv;
    PL_utf8_lower	= Nullsv;
    PL_utf8_print	= Nullsv;
    PL_utf8_punct	= Nullsv;
    PL_utf8_xdigit	= Nullsv;
    PL_utf8_mark	= Nullsv;
    PL_utf8_toupper	= Nullsv;
    PL_utf8_totitle	= Nullsv;
    PL_utf8_tolower	= Nullsv;
    PL_utf8_tofold	= Nullsv;
    PL_utf8_idstart	= Nullsv;
    PL_utf8_idcont	= Nullsv;

    if (!specialWARN(PL_compiling.cop_warnings))
	SvREFCNT_dec(PL_compiling.cop_warnings);
    PL_compiling.cop_warnings = Nullsv;
    if (!specialCopIO(PL_compiling.cop_io))
	SvREFCNT_dec(PL_compiling.cop_io);
    PL_compiling.cop_io = Nullsv;
    CopFILE_free(&PL_compiling);
    CopSTASH_free(&PL_compiling);

    /* Prepare to destruct main symbol table.  */

    hv = PL_defstash;
    PL_defstash = 0;
    SvREFCNT_dec(hv);
    SvREFCNT_dec(PL_curstname);
    PL_curstname = Nullsv;

    /* clear queued errors */
    SvREFCNT_dec(PL_errors);
    PL_errors = Nullsv;

    FREETMPS;
    if (destruct_level >= 2 && ckWARN_d(WARN_INTERNAL)) {
	if (PL_scopestack_ix != 0)
	    Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
	         "Unbalanced scopes: %ld more ENTERs than LEAVEs\n",
		 (long)PL_scopestack_ix);
	if (PL_savestack_ix != 0)
	    Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
		 "Unbalanced saves: %ld more saves than restores\n",
		 (long)PL_savestack_ix);
	if (PL_tmps_floor != -1)
	    Perl_warner(aTHX_ packWARN(WARN_INTERNAL),"Unbalanced tmps: %ld more allocs than frees\n",
		 (long)PL_tmps_floor + 1);
	if (cxstack_ix != -1)
	    Perl_warner(aTHX_ packWARN(WARN_INTERNAL),"Unbalanced context: %ld more PUSHes than POPs\n",
		 (long)cxstack_ix + 1);
    }

    /* Now absolutely destruct everything, somehow or other, loops or no. */
    SvFLAGS(PL_fdpid) |= SVTYPEMASK;		/* don't clean out pid table now */
    SvFLAGS(PL_strtab) |= SVTYPEMASK;		/* don't clean out strtab now */

    /* the 2 is for PL_fdpid and PL_strtab */
    while (PL_sv_count > 2 && sv_clean_all())
	;

    SvFLAGS(PL_fdpid) &= ~SVTYPEMASK;
    SvFLAGS(PL_fdpid) |= SVt_PVAV;
    SvFLAGS(PL_strtab) &= ~SVTYPEMASK;
    SvFLAGS(PL_strtab) |= SVt_PVHV;

    AvREAL_off(PL_fdpid);		/* no surviving entries */
    SvREFCNT_dec(PL_fdpid);		/* needed in io_close() */
    PL_fdpid = Nullav;

#ifdef HAVE_INTERP_INTERN
    sys_intern_clear();
#endif

    /* Destruct the global string table. */
    {
	/* Yell and reset the HeVAL() slots that are still holding refcounts,
	 * so that sv_free() won't fail on them.
	 */
	I32 riter;
	I32 max;
	HE *hent;
	HE **array;

	riter = 0;
	max = HvMAX(PL_strtab);
	array = HvARRAY(PL_strtab);
	hent = array[0];
	for (;;) {
	    if (hent && ckWARN_d(WARN_INTERNAL)) {
		Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
		     "Unbalanced string table refcount: (%d) for \"%s\"",
		     HeVAL(hent) - Nullsv, HeKEY(hent));
		HeVAL(hent) = Nullsv;
		hent = HeNEXT(hent);
	    }
	    if (!hent) {
		if (++riter > max)
		    break;
		hent = array[riter];
	    }
	}
    }
    SvREFCNT_dec(PL_strtab);

#ifdef USE_ITHREADS
    /* free the pointer table used for cloning */
    ptr_table_free(PL_ptr_table);
    PL_ptr_table = (PTR_TBL_t*)NULL;
#endif

    /* free special SVs */

    SvREFCNT(&PL_sv_yes) = 0;
    sv_clear(&PL_sv_yes);
    SvANY(&PL_sv_yes) = NULL;
    SvFLAGS(&PL_sv_yes) = 0;

    SvREFCNT(&PL_sv_no) = 0;
    sv_clear(&PL_sv_no);
    SvANY(&PL_sv_no) = NULL;
    SvFLAGS(&PL_sv_no) = 0;

    {
        int i;
        for (i=0; i<=2; i++) {
            SvREFCNT(PERL_DEBUG_PAD(i)) = 0;
            sv_clear(PERL_DEBUG_PAD(i));
            SvANY(PERL_DEBUG_PAD(i)) = NULL;
            SvFLAGS(PERL_DEBUG_PAD(i)) = 0;
        }
    }

    if (PL_sv_count != 0 && ckWARN_d(WARN_INTERNAL))
	Perl_warner(aTHX_ packWARN(WARN_INTERNAL),"Scalars leaked: %ld\n", (long)PL_sv_count);

#ifdef DEBUG_LEAKING_SCALARS
    if (PL_sv_count != 0) {
	SV* sva;
	SV* sv;
	register SV* svend;

	for (sva = PL_sv_arenaroot; sva; sva = (SV*)SvANY(sva)) {
	    svend = &sva[SvREFCNT(sva)];
	    for (sv = sva + 1; sv < svend; ++sv) {
		if (SvTYPE(sv) != SVTYPEMASK) {
		    PerlIO_printf(Perl_debug_log, "leaked: sv=0x%p"
			" flags=0x08%"UVxf
			" refcnt=%"UVuf pTHX__FORMAT "\n",
			sv, sv->sv_flags, sv->sv_refcnt pTHX__VALUE);
		}
	    }
	}
    }
#endif
    PL_sv_count = 0;


#if defined(PERLIO_LAYERS)
    /* No more IO - including error messages ! */
    PerlIO_cleanup(aTHX);
#endif

    /* sv_undef needs to stay immortal until after PerlIO_cleanup
       as currently layers use it rather than Nullsv as a marker
       for no arg - and will try and SvREFCNT_dec it.
     */
    SvREFCNT(&PL_sv_undef) = 0;
    SvREADONLY_off(&PL_sv_undef);

    Safefree(PL_origfilename);
    PL_origfilename = Nullch;
    Safefree(PL_reg_start_tmp);
    PL_reg_start_tmp = (char**)NULL;
    PL_reg_start_tmpl = 0;
    if (PL_reg_curpm)
	Safefree(PL_reg_curpm);
    Safefree(PL_reg_poscache);
    free_tied_hv_pool();
    Safefree(PL_op_mask);
    Safefree(PL_psig_ptr);
    PL_psig_ptr = (SV**)NULL;
    Safefree(PL_psig_name);
    PL_psig_name = (SV**)NULL;
    Safefree(PL_bitcount);
    PL_bitcount = Nullch;
    Safefree(PL_psig_pend);
    PL_psig_pend = (int*)NULL;
    PL_formfeed = Nullsv;
    Safefree(PL_ofmt);
    PL_ofmt = Nullch;
    nuke_stacks();
    PL_tainting = FALSE;
    PL_taint_warn = FALSE;
    PL_hints = 0;		/* Reset hints. Should hints be per-interpreter ? */
    PL_debug = 0;

    DEBUG_P(debprofdump());

#ifdef USE_REENTRANT_API
    Perl_reentrant_free(aTHX);
#endif

    sv_free_arenas();

    /* As the absolutely last thing, free the non-arena SV for mess() */

    if (PL_mess_sv) {
	/* it could have accumulated taint magic */
	if (SvTYPE(PL_mess_sv) >= SVt_PVMG) {
	    MAGIC* mg;
	    MAGIC* moremagic;
	    for (mg = SvMAGIC(PL_mess_sv); mg; mg = moremagic) {
		moremagic = mg->mg_moremagic;
		if (mg->mg_ptr && mg->mg_type != PERL_MAGIC_regex_global
						&& mg->mg_len >= 0)
		    Safefree(mg->mg_ptr);
		Safefree(mg);
	    }
	}
	/* we know that type >= SVt_PV */
	SvOOK_off(PL_mess_sv);
	Safefree(SvPVX(PL_mess_sv));
	Safefree(SvANY(PL_mess_sv));
	Safefree(PL_mess_sv);
	PL_mess_sv = Nullsv;
    }
    return STATUS_NATIVE_EXPORT;
}

/*
=for apidoc perl_free

Releases a Perl interpreter.  See L<perlembed>.

=cut
*/

void
perl_free(pTHXx)
{
#if defined(WIN32) || defined(NETWARE)
#  if defined(PERL_IMPLICIT_SYS)
#    ifdef NETWARE
    void *host = nw_internal_host;
#    else
    void *host = w32_internal_host;
#    endif
    PerlMem_free(aTHXx);
#    ifdef NETWARE
    nw_delete_internal_host(host);
#    else
    win32_delete_internal_host(host);
#    endif
#  else
    PerlMem_free(aTHXx);
#  endif
#else
    PerlMem_free(aTHXx);
#endif
}

void
Perl_call_atexit(pTHX_ ATEXIT_t fn, void *ptr)
{
    Renew(PL_exitlist, PL_exitlistlen+1, PerlExitListEntry);
    PL_exitlist[PL_exitlistlen].fn = fn;
    PL_exitlist[PL_exitlistlen].ptr = ptr;
    ++PL_exitlistlen;
}

/*
=for apidoc perl_parse

Tells a Perl interpreter to parse a Perl script.  See L<perlembed>.

=cut
*/

int
perl_parse(pTHXx_ XSINIT_t xsinit, int argc, char **argv, char **env)
{
    I32 oldscope;
    int ret;
    dJMPENV;
#ifdef USE_5005THREADS
    dTHX;
#endif

#ifdef SETUID_SCRIPTS_ARE_SECURE_NOW
#ifdef IAMSUID
#undef IAMSUID
    Perl_croak(aTHX_ "suidperl is no longer needed since the kernel can now execute\n\
setuid perl scripts securely.\n");
#endif /* IAMSUID */
#endif

#if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
    /* [perl #22371] Algorimic Complexity Attack on Perl 5.6.1, 5.8.0
     * This MUST be done before any hash stores or fetches take place.
     * If you set PL_rehash_seed (and assumedly also PL_rehash_seed_set)
     * yourself, it is your responsibility to provide a good random seed!
     * You can also define PERL_HASH_SEED in compile time, see hv.h. */
    if (!PL_rehash_seed_set)
	 PL_rehash_seed = get_hash_seed();
    {
	 char *s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG");

	 if (s) {
	      int i = atoi(s);

	      if (i == 1)
		   PerlIO_printf(Perl_debug_log, "HASH_SEED = %"UVuf"\n",
				 PL_rehash_seed);
	 }
    }
#endif /* #if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) */

    PL_origargc = argc;
    PL_origargv = argv;

    {
	/* Set PL_origalen be the sum of the contiguous argv[]
	 * elements plus the size of the env in case that it is
	 * contiguous with the argv[].  This is used in mg.c:Perl_magic_set()
	 * as the maximum modifiable length of $0.  In the worst case
	 * the area we are able to modify is limited to the size of
	 * the original argv[0].  (See below for 'contiguous', though.)
	 * --jhi */
	 char *s = NULL;
	 int i;
	 UV mask =
	   ~(UV)(PTRSIZE == 4 ? 3 : PTRSIZE == 8 ? 7 : PTRSIZE == 16 ? 15 : 0);
         /* Do the mask check only if the args seem like aligned. */
	 UV aligned =
	   (mask < ~(UV)0) && ((PTR2UV(argv[0]) & mask) == PTR2UV(argv[0]));

	 /* See if all the arguments are contiguous in memory.  Note
	  * that 'contiguous' is a loose term because some platforms
	  * align the argv[] and the envp[].  If the arguments look
	  * like non-aligned, assume that they are 'strictly' or
	  * 'traditionally' contiguous.  If the arguments look like
	  * aligned, we just check that they are within aligned
	  * PTRSIZE bytes.  As long as no system has something bizarre
	  * like the argv[] interleaved with some other data, we are
	  * fine.  (Did I just evoke Murphy's Law?)  --jhi */
	 if (PL_origargv && PL_origargc >= 1 && (s = PL_origargv[0])) {
	      while (*s) s++;
	      for (i = 1; i < PL_origargc; i++) {
		   if ((PL_origargv[i] == s + 1
#ifdef OS2
			|| PL_origargv[i] == s + 2
#endif 
			    )
		       ||
		       (aligned &&
			(PL_origargv[i] >  s &&
			 PL_origargv[i] <=
			 INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)))
			)
		   {
			s = PL_origargv[i];
			while (*s) s++;
		   }
		   else
			break;
	      }
	 }
	 /* Can we grab env area too to be used as the area for $0? */
	 if (PL_origenviron) {
	      if ((PL_origenviron[0] == s + 1
#ifdef OS2
		   || (PL_origenviron[0] == s + 9 && (s += 8))
#endif 
		  )
		  ||
		  (aligned &&
		   (PL_origenviron[0] >  s &&
		    PL_origenviron[0] <=
		    INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)))
		 )
	      {
#ifndef OS2
		   s = PL_origenviron[0];
		   while (*s) s++;
#endif
		   my_setenv("NoNe  SuCh", Nullch);
		   /* Force copy of environment. */
		   for (i = 1; PL_origenviron[i]; i++) {
			if (PL_origenviron[i] == s + 1
			    ||
			    (aligned &&
			     (PL_origenviron[i] >  s &&
			      PL_origenviron[i] <=
			      INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)))
			   )
			{
			     s = PL_origenviron[i];
			     while (*s) s++;
			}
			else
			     break;
		   }
	      }
	 }
	 PL_origalen = s - PL_origargv[0] + 1;
    }

    if (PL_do_undump) {

	/* Come here if running an undumped a.out. */

	PL_origfilename = savepv(argv[0]);
	PL_do_undump = FALSE;
	cxstack_ix = -1;		/* start label stack again */
	init_ids();
	init_postdump_symbols(argc,argv,env);
	return 0;
    }

    if (PL_main_root) {
	op_free(PL_main_root);
	PL_main_root = Nullop;
    }
    PL_main_start = Nullop;
    SvREFCNT_dec(PL_main_cv);
    PL_main_cv = Nullcv;

    time(&PL_basetime);
    oldscope = PL_scopestack_ix;
    PL_dowarn = G_WARN_OFF;

#ifdef PERL_FLEXIBLE_EXCEPTIONS
    CALLPROTECT(aTHX_ pcur_env, &ret, MEMBER_TO_FPTR(S_vparse_body), env, xsinit);
#else
    JMPENV_PUSH(ret);
#endif
    switch (ret) {
    case 0:
#ifndef PERL_FLEXIBLE_EXCEPTIONS
	parse_body(env,xsinit);
#endif
	if (PL_checkav)
	    call_list(oldscope, PL_checkav);
	ret = 0;
	break;
    case 1:
	STATUS_ALL_FAILURE;
	/* FALL THROUGH */
    case 2:
	/* my_exit() was called */
	while (PL_scopestack_ix > oldscope)
	    LEAVE;
	FREETMPS;
	PL_curstash = PL_defstash;
	if (PL_checkav)
	    call_list(oldscope, PL_checkav);
	ret = STATUS_NATIVE_EXPORT;
	break;
    case 3:
	PerlIO_printf(Perl_error_log, "panic: top_env\n");
	ret = 1;
	break;
    }
    JMPENV_POP;
    return ret;
}

#ifdef PERL_FLEXIBLE_EXCEPTIONS
STATIC void *
S_vparse_body(pTHX_ va_list args)
{
    char **env = va_arg(args, char**);
    XSINIT_t xsinit = va_arg(args, XSINIT_t);

    return parse_body(env, xsinit);
}
#endif

STATIC void *
S_parse_body(pTHX_ char **env, XSINIT_t xsinit)
{
    int argc = PL_origargc;
    char **argv = PL_origargv;
    char *scriptname = NULL;
    VOL bool dosearch = FALSE;
    char *validarg = "";
    register SV *sv;
    register char *s;
    char *cddir = Nullch;

    PL_fdscript = -1;
    PL_suidscript = -1;
    sv_setpvn(PL_linestr,"",0);
    sv = newSVpvn("",0);		/* first used for -I flags */
    SAVEFREESV(sv);
    init_main_stash();

    for (argc--,argv++; argc > 0; argc--,argv++) {
	if (argv[0][0] != '-' || !argv[0][1])
	    break;
#ifdef DOSUID
    if (*validarg)
	validarg = " PHOOEY ";
    else
	validarg = argv[0];
    /*
     * Can we rely on the kernel to start scripts with argv[1] set to
     * contain all #! line switches (the whole line)? (argv[0] is set to
     * the interpreter name, argv[2] to the script name; argv[3] and
     * above may contain other arguments.)
     */
#endif
	s = argv[0]+1;
      reswitch:
	switch (*s) {
	case 'C':
#ifndef PERL_STRICT_CR
	case '\r':
#endif
	case ' ':
	case '0':
	case 'F':
	case 'a':
	case 'c':
	case 'd':
	case 'D':
	case 'h':
	case 'i':
	case 'l':
	case 'M':
	case 'm':
	case 'n':
	case 'p':
	case 's':
	case 'u':
	case 'U':
	case 'v':
	case 'W':
	case 'X':
	case 'w':
	case 'A':
	    if ((s = moreswitches(s)))
		goto reswitch;
	    break;

	case 't':
	    CHECK_MALLOC_TOO_LATE_FOR('t');
	    if( !PL_tainting ) {
	         PL_taint_warn = TRUE;
	         PL_tainting = TRUE;
	    }
	    s++;
	    goto reswitch;
	case 'T':
	    CHECK_MALLOC_TOO_LATE_FOR('T');
	    PL_tainting = TRUE;
	    PL_taint_warn = FALSE;
	    s++;
	    goto reswitch;

	case 'e':
#ifdef MACOS_TRADITIONAL
	    /* ignore -e for Dev:Pseudo argument */
	    if (argv[1] && !strcmp(argv[1], "Dev:Pseudo"))
		break;
#endif
	    forbid_setid("-e");
	    if (!PL_e_script) {
		PL_e_script = newSVpvn("",0);
		filter_add(read_e_script, NULL);
	    }
	    if (*++s)
		sv_catpv(PL_e_script, s);
	    else if (argv[1]) {
		sv_catpv(PL_e_script, argv[1]);
		argc--,argv++;
	    }
	    else
		Perl_croak(aTHX_ "No code specified for -e");
	    sv_catpv(PL_e_script, "\n");
	    break;

	case 'I':	/* -I handled both here and in moreswitches() */
	    forbid_setid("-I");
	    if (!*++s && (s=argv[1]) != Nullch) {
		argc--,argv++;
	    }
	    if (s && *s) {
		char *p;
		STRLEN len = strlen(s);
		p = savepvn(s, len);
		incpush(p, TRUE, TRUE, FALSE);
		sv_catpvn(sv, "-I", 2);
		sv_catpvn(sv, p, len);
		sv_catpvn(sv, " ", 1);
		Safefree(p);
	    }
	    else
		Perl_croak(aTHX_ "No directory specified for -I");
	    break;
	case 'P':
	    forbid_setid("-P");
	    PL_preprocess = TRUE;
	    s++;
	    goto reswitch;
	case 'S':
	    forbid_setid("-S");
	    dosearch = TRUE;
	    s++;
	    goto reswitch;
	case 'V':
	    if (!PL_preambleav)
		PL_preambleav = newAV();
	    av_push(PL_preambleav, newSVpv("use Config qw(myconfig config_vars)",0));
	    if (*++s != ':')  {
		PL_Sv = newSVpv("print myconfig();",0);
#ifdef VMS
		sv_catpv(PL_Sv,"print \"\\nCharacteristics of this PERLSHR image: \\n\",");
#else
		sv_catpv(PL_Sv,"print \"\\nCharacteristics of this binary (from libperl): \\n\",");
#endif
		sv_catpv(PL_Sv,"\"  Compile-time options:");
#  ifdef DEBUGGING
		sv_catpv(PL_Sv," DEBUGGING");
#  endif
#  ifdef MULTIPLICITY
		sv_catpv(PL_Sv," MULTIPLICITY");
#  endif
#  ifdef USE_5005THREADS
		sv_catpv(PL_Sv," USE_5005THREADS");
#  endif
#  ifdef USE_ITHREADS
		sv_catpv(PL_Sv," USE_ITHREADS");
#  endif
#  ifdef USE_64_BIT_INT
		sv_catpv(PL_Sv," USE_64_BIT_INT");
#  endif
#  ifdef USE_64_BIT_ALL
		sv_catpv(PL_Sv," USE_64_BIT_ALL");
#  endif
#  ifdef USE_LONG_DOUBLE
		sv_catpv(PL_Sv," USE_LONG_DOUBLE");
#  endif
#  ifdef USE_LARGE_FILES
		sv_catpv(PL_Sv," USE_LARGE_FILES");
#  endif
#  ifdef USE_SOCKS
		sv_catpv(PL_Sv," USE_SOCKS");
#  endif
#  ifdef PERL_IMPLICIT_CONTEXT
		sv_catpv(PL_Sv," PERL_IMPLICIT_CONTEXT");
#  endif
#  ifdef PERL_IMPLICIT_SYS
		sv_catpv(PL_Sv," PERL_IMPLICIT_SYS");
#  endif
		sv_catpv(PL_Sv,"\\n\",");

#if defined(LOCAL_PATCH_COUNT)
		if (LOCAL_PATCH_COUNT > 0) {
		    int i;
		    sv_catpv(PL_Sv,"\"  Locally applied patches:\\n\",");
		    for (i = 1; i <= LOCAL_PATCH_COUNT; i++) {
			if (PL_localpatches[i])
			    Perl_sv_catpvf(aTHX_ PL_Sv,"q%c\t%s\n%c,",
				    0, PL_localpatches[i], 0);
		    }
		}
#endif
		Perl_sv_catpvf(aTHX_ PL_Sv,"\"  Built under %s\\n\"",OSNAME);
#ifdef __DATE__
#  ifdef __TIME__
		Perl_sv_catpvf(aTHX_ PL_Sv,",\"  Compiled at %s %s\\n\"",__DATE__,__TIME__);
#  else
		Perl_sv_catpvf(aTHX_ PL_Sv,",\"  Compiled on %s\\n\"",__DATE__);
#  endif
#endif
		sv_catpv(PL_Sv, "; \
$\"=\"\\n    \"; \
@env = map { \"$_=\\\"$ENV{$_}\\\"\" } sort grep {/^PERL/} keys %ENV; ");
#ifdef __CYGWIN__
		sv_catpv(PL_Sv,"\
push @env, \"CYGWIN=\\\"$ENV{CYGWIN}\\\"\";");
#endif
		sv_catpv(PL_Sv, "\
print \"  \\%ENV:\\n    @env\\n\" if @env; \
print \"  \\@INC:\\n    @INC\\n\";");
	    }
	    else {
		PL_Sv = newSVpv("config_vars(qw(",0);
		sv_catpv(PL_Sv, ++s);
		sv_catpv(PL_Sv, "))");
		s += strlen(s);
	    }
	    av_push(PL_preambleav, PL_Sv);
	    scriptname = BIT_BUCKET;	/* don't look for script or read stdin */
	    goto reswitch;
	case 'x':
	    PL_doextract = TRUE;
	    s++;
	    if (*s)
		cddir = s;
	    break;
	case 0:
	    break;
	case '-':
	    if (!*++s || isSPACE(*s)) {
		argc--,argv++;
		goto switch_end;
	    }
	    /* catch use of gnu style long options */
	    if (strEQ(s, "version")) {
		s = "v";
		goto reswitch;
	    }
	    if (strEQ(s, "help")) {
		s = "h";
		goto reswitch;
	    }
	    s--;
	    /* FALL THROUGH */
	default:
	    Perl_croak(aTHX_ "Unrecognized switch: -%s  (-h will show valid options)",s);
	}
    }
  switch_end:

    if (
#ifndef SECURE_INTERNAL_GETENV
        !PL_tainting &&
#endif
	(s = PerlEnv_getenv("PERL5OPT")))
    {
    	char *popt = s;
	while (isSPACE(*s))
	    s++;
	if (*s == '-' && *(s+1) == 'T') {
	    CHECK_MALLOC_TOO_LATE_FOR('T');
	    PL_tainting = TRUE;
            PL_taint_warn = FALSE;
	}
	else {
	    char *popt_copy = Nullch;
	    while (s && *s) {
	        char *d;
		while (isSPACE(*s))
		    s++;
		if (*s == '-') {
		    s++;
		    if (isSPACE(*s))
			continue;
		}
		d = s;
		if (!*s)
		    break;
		if (!strchr("DIMUdmtwA", *s))
		    Perl_croak(aTHX_ "Illegal switch in PERL5OPT: -%c", *s);
		while (++s && *s) {
		    if (isSPACE(*s)) {
			if (!popt_copy) {
			    popt_copy = SvPVX(sv_2mortal(newSVpv(popt,0)));
			    s = popt_copy + (s - popt);
			    d = popt_copy + (d - popt);
			}
		        *s++ = '\0';
			break;
		    }
		}
		if (*d == 't') {
		    if( !PL_tainting ) {
		        PL_taint_warn = TRUE;
		        PL_tainting = TRUE;
		    }
		} else {
		    moreswitches(d);
		}
	    }
	}
    }

    if (PL_taint_warn && PL_dowarn != G_WARN_ALL_OFF) {
       PL_compiling.cop_warnings = newSVpvn(WARN_TAINTstring, WARNsize);
    }

    if (!scriptname)
	scriptname = argv[0];
    if (PL_e_script) {
	argc++,argv--;
	scriptname = BIT_BUCKET;	/* don't look for script or read stdin */
    }
    else if (scriptname == Nullch) {
#ifdef MSDOS
	if ( PerlLIO_isatty(PerlIO_fileno(PerlIO_stdin())) )
	    moreswitches("h");
#endif
	scriptname = "-";
    }

    init_perllib();

    open_script(scriptname,dosearch,sv);

    validate_suid(validarg, scriptname);

#ifndef PERL_MICRO
#if defined(SIGCHLD) || defined(SIGCLD)
    {
#ifndef SIGCHLD
#  define SIGCHLD SIGCLD
#endif
	Sighandler_t sigstate = rsignal_state(SIGCHLD);
	if (sigstate == SIG_IGN) {
	    if (ckWARN(WARN_SIGNAL))
		Perl_warner(aTHX_ packWARN(WARN_SIGNAL),
			    "Can't ignore signal CHLD, forcing to default");
	    (void)rsignal(SIGCHLD, (Sighandler_t)SIG_DFL);
	}
    }
#endif
#endif

#ifdef MACOS_TRADITIONAL
    if (PL_doextract || gMacPerl_AlwaysExtract) {
#else
    if (PL_doextract) {
#endif
	find_beginning();
	if (cddir && PerlDir_chdir(cddir) < 0)
	    Perl_croak(aTHX_ "Can't chdir to %s",cddir);

    }

    PL_main_cv = PL_compcv = (CV*)NEWSV(1104,0);
    sv_upgrade((SV *)PL_compcv, SVt_PVCV);
    CvUNIQUE_on(PL_compcv);

    CvPADLIST(PL_compcv) = pad_new(0);
#ifdef USE_5005THREADS
    CvOWNER(PL_compcv) = 0;
    New(666, CvMUTEXP(PL_compcv), 1, perl_mutex);
    MUTEX_INIT(CvMUTEXP(PL_compcv));
#endif /* USE_5005THREADS */

    boot_core_PerlIO();
    boot_core_UNIVERSAL();
    boot_core_xsutils();

    if (xsinit)
	(*xsinit)(aTHX);	/* in case linked C routines want magical variables */
#ifndef PERL_MICRO
#if defined(VMS) || defined(WIN32) || defined(DJGPP) || defined(__CYGWIN__) || defined(EPOC)
    init_os_extras();
#endif
#endif

#ifdef USE_SOCKS
#   ifdef HAS_SOCKS5_INIT
    socks5_init(argv[0]);
#   else
    SOCKSinit(argv[0]);
#   endif
#endif

    init_predump_symbols();
    /* init_postdump_symbols not currently designed to be called */
    /* more than once (ENV isn't cleared first, for example)	 */
    /* But running with -u leaves %ENV & @ARGV undefined!    XXX */
    if (!PL_do_undump)
	init_postdump_symbols(argc,argv,env);

    /* PL_unicode is turned on by -C or by $ENV{PERL_UNICODE}.
     * PL_utf8locale is conditionally turned on by
     * locale.c:Perl_init_i18nl10n() if the environment
     * look like the user wants to use UTF-8. */
    if (PL_unicode) {
	 /* Requires init_predump_symbols(). */
	 if (!(PL_unicode & PERL_UNICODE_LOCALE_FLAG) || PL_utf8locale) {
	      IO* io;
	      PerlIO* fp;
	      SV* sv;

	      /* Turn on UTF-8-ness on STDIN, STDOUT, STDERR
	       * and the default open disciplines. */
	      if ((PL_unicode & PERL_UNICODE_STDIN_FLAG) &&
		  PL_stdingv  && (io = GvIO(PL_stdingv)) &&
		  (fp = IoIFP(io)))
		   PerlIO_binmode(aTHX_ fp, IoTYPE(io), 0, ":utf8");
	      if ((PL_unicode & PERL_UNICODE_STDOUT_FLAG) &&
		  PL_defoutgv && (io = GvIO(PL_defoutgv)) &&
		  (fp = IoOFP(io)))
		   PerlIO_binmode(aTHX_ fp, IoTYPE(io), 0, ":utf8");
	      if ((PL_unicode & PERL_UNICODE_STDERR_FLAG) &&
		  PL_stderrgv && (io = GvIO(PL_stderrgv)) &&
		  (fp = IoOFP(io)))
		   PerlIO_binmode(aTHX_ fp, IoTYPE(io), 0, ":utf8");
	      if ((PL_unicode & PERL_UNICODE_INOUT_FLAG) &&
		  (sv = GvSV(gv_fetchpv("\017PEN", TRUE, SVt_PV)))) {
		   U32 in  = PL_unicode & PERL_UNICODE_IN_FLAG;
		   U32 out = PL_unicode & PERL_UNICODE_OUT_FLAG;
		   if (in) {
			if (out)
			     sv_setpvn(sv, ":utf8\0:utf8", 11);
			else
			     sv_setpvn(sv, ":utf8\0", 6);
		   }
		   else if (out)
			sv_setpvn(sv, "\0:utf8", 6);
		   SvSETMAGIC(sv);
	      }
	 }
    }

    if ((s = PerlEnv_getenv("PERL_SIGNALS"))) {
	 if (strEQ(s, "unsafe"))
	      PL_signals |=  PERL_SIGNALS_UNSAFE_FLAG;
	 else if (strEQ(s, "safe"))
	      PL_signals &= ~PERL_SIGNALS_UNSAFE_FLAG;
	 else
	      Perl_croak(aTHX_ "PERL_SIGNALS illegal: \"%s\"", s);
    }

    init_lexer();

    /* now parse the script */

    SETERRNO(0,SS_NORMAL);
    PL_error_count = 0;
#ifdef MACOS_TRADITIONAL
    if (gMacPerl_SyntaxError = (yyparse() || PL_error_count)) {
	if (PL_minus_c)
	    Perl_croak(aTHX_ "%s had compilation errors.\n", MacPerl_MPWFileName(PL_origfilename));
	else {
	    Perl_croak(aTHX_ "Execution of %s aborted due to compilation errors.\n",
		       MacPerl_MPWFileName(PL_origfilename));
	}
    }
#else
    if (yyparse() || PL_error_count) {
	if (PL_minus_c)
	    Perl_croak(aTHX_ "%s had compilation errors.\n", PL_origfilename);
	else {
	    Perl_croak(aTHX_ "Execution of %s aborted due to compilation errors.\n",
		       PL_origfilename);
	}
    }
#endif
    CopLINE_set(PL_curcop, 0);
    PL_curstash = PL_defstash;
    PL_preprocess = FALSE;
    if (PL_e_script) {
	SvREFCNT_dec(PL_e_script);
	PL_e_script = Nullsv;
    }

    if (PL_do_undump)
	my_unexec();

    if (isWARN_ONCE) {
	SAVECOPFILE(PL_curcop);
	SAVECOPLINE(PL_curcop);
	gv_check(PL_defstash);
    }

    LEAVE;
    FREETMPS;

#ifdef MYMALLOC
    if ((s=PerlEnv_getenv("PERL_DEBUG_MSTATS")) && atoi(s) >= 2)
	dump_mstats("after compilation:");
#endif

    ENTER;
    PL_restartop = 0;
    return NULL;
}

/*
=for apidoc perl_run

Tells a Perl interpreter to run.  See L<perlembed>.

=cut
*/

int
perl_run(pTHXx)
{
    I32 oldscope;
    int ret = 0;
    dJMPENV;
#ifdef USE_5005THREADS
    dTHX;
#endif

    oldscope = PL_scopestack_ix;
#ifdef VMS
    VMSISH_HUSHED = 0;
#endif

#ifdef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
    CALLPROTECT(aTHX_ pcur_env, &ret, MEMBER_TO_FPTR(S_vrun_body), oldscope);
#else
    JMPENV_PUSH(ret);
#endif
    switch (ret) {
    case 1:
	cxstack_ix = -1;		/* start context stack again */
	goto redo_body;
    case 0:				/* normal completion */
#ifndef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
	run_body(oldscope);
#endif
	/* FALL THROUGH */
    case 2:				/* my_exit() */
	while (PL_scopestack_ix > oldscope)
	    LEAVE;
	FREETMPS;
	PL_curstash = PL_defstash;
	if (!(PL_exit_flags & PERL_EXIT_DESTRUCT_END) &&
	    PL_endav && !PL_minus_c)
	    call_list(oldscope, PL_endav);
#ifdef MYMALLOC
	if (PerlEnv_getenv("PERL_DEBUG_MSTATS"))
	    dump_mstats("after execution:  ");
#endif
	ret = STATUS_NATIVE_EXPORT;
	break;
    case 3:
	if (PL_restartop) {
	    POPSTACK_TO(PL_mainstack);
	    goto redo_body;
	}
	PerlIO_printf(Perl_error_log, "panic: restartop\n");
	FREETMPS;
	ret = 1;
	break;
    }

    JMPENV_POP;
    return ret;
}

#ifdef PERL_FLEXIBLE_EXCEPTIONS
STATIC void *
S_vrun_body(pTHX_ va_list args)
{
    I32 oldscope = va_arg(args, I32);

    return run_body(oldscope);
}
#endif


STATIC void *
S_run_body(pTHX_ I32 oldscope)
{
    DEBUG_r(PerlIO_printf(Perl_debug_log, "%s $` $& $' support.\n",
                    PL_sawampersand ? "Enabling" : "Omitting"));

    if (!PL_restartop) {
	DEBUG_x(dump_all());
	if (!DEBUG_q_TEST)
	  PERL_DEBUG(PerlIO_printf(Perl_debug_log, "\nEXECUTING...\n\n"));
	DEBUG_S(PerlIO_printf(Perl_debug_log, "main thread is 0x%"UVxf"\n",
			      PTR2UV(thr)));

	if (PL_minus_c) {
#ifdef MACOS_TRADITIONAL
	    PerlIO_printf(Perl_error_log, "%s%s syntax OK\n",
		(gMacPerl_ErrorFormat ? "# " : ""),
		MacPerl_MPWFileName(PL_origfilename));
#else
	    PerlIO_printf(Perl_error_log, "%s syntax OK\n", PL_origfilename);
#endif
	    my_exit(0);
	}
	if (PERLDB_SINGLE && PL_DBsingle)
	    sv_setiv(PL_DBsingle, 1);
	if (PL_initav)
	    call_list(oldscope, PL_initav);
    }

    /* do it */

    if (PL_restartop) {
	PL_op = PL_restartop;
	PL_restartop = 0;
	CALLRUNOPS(aTHX);
    }
    else if (PL_main_start) {
	CvDEPTH(PL_main_cv) = 1;
	PL_op = PL_main_start;
	CALLRUNOPS(aTHX);
    }

    my_exit(0);
    /* NOTREACHED */
    return NULL;
}

/*
=head1 SV Manipulation Functions

=for apidoc p||get_sv

Returns the SV of the specified Perl scalar.  If C<create> is set and the
Perl variable does not exist then it will be created.  If C<create> is not
set and the variable does not exist then NULL is returned.

=cut
*/

SV*
Perl_get_sv(pTHX_ const char *name, I32 create)
{
    GV *gv;
#ifdef USE_5005THREADS
    if (name[1] == '\0' && !isALPHA(name[0])) {
	PADOFFSET tmp = find_threadsv(name);
    	if (tmp != NOT_IN_PAD)
	    return THREADSV(tmp);
    }
#endif /* USE_5005THREADS */
    gv = gv_fetchpv(name, create, SVt_PV);
    if (gv)
	return GvSV(gv);
    return Nullsv;
}

/*
=head1 Array Manipulation Functions

=for apidoc p||get_av

Returns the AV of the specified Perl array.  If C<create> is set and the
Perl variable does not exist then it will be created.  If C<create> is not
set and the variable does not exist then NULL is returned.

=cut
*/

AV*
Perl_get_av(pTHX_ const char *name, I32 create)
{
    GV* gv = gv_fetchpv(name, create, SVt_PVAV);
    if (create)
    	return GvAVn(gv);
    if (gv)
	return GvAV(gv);
    return Nullav;
}

/*
=head1 Hash Manipulation Functions

=for apidoc p||get_hv

Returns the HV of the specified Perl hash.  If C<create> is set and the
Perl variable does not exist then it will be created.  If C<create> is not
set and the variable does not exist then NULL is returned.

=cut
*/

HV*
Perl_get_hv(pTHX_ const char *name, I32 create)
{
    GV* gv = gv_fetchpv(name, create, SVt_PVHV);
    if (create)
    	return GvHVn(gv);
    if (gv)
	return GvHV(gv);
    return Nullhv;
}

/*
=head1 CV Manipulation Functions

=for apidoc p||get_cv

Returns the CV of the specified Perl subroutine.  If C<create> is set and
the Perl subroutine does not exist then it will be declared (which has the
same effect as saying C<sub name;>).  If C<create> is not set and the
subroutine does not exist then NULL is returned.

=cut
*/

CV*
Perl_get_cv(pTHX_ const char *name, I32 create)
{
    GV* gv = gv_fetchpv(name, create, SVt_PVCV);
    /* XXX unsafe for threads if eval_owner isn't held */
    /* XXX this is probably not what they think they're getting.
     * It has the same effect as "sub name;", i.e. just a forward
     * declaration! */
    if (create && !GvCVu(gv))
    	return newSUB(start_subparse(FALSE, 0),
		      newSVOP(OP_CONST, 0, newSVpv(name,0)),
		      Nullop,
		      Nullop);
    if (gv)
	return GvCVu(gv);
    return Nullcv;
}

/* Be sure to refetch the stack pointer after calling these routines. */

/*

=head1 Callback Functions

=for apidoc p||call_argv

Performs a callback to the specified Perl sub.  See L<perlcall>.

=cut
*/

I32
Perl_call_argv(pTHX_ const char *sub_name, I32 flags, register char **argv)

          		/* See G_* flags in cop.h */
                     	/* null terminated arg list */
{
    dSP;

    PUSHMARK(SP);
    if (argv) {
	while (*argv) {
	    XPUSHs(sv_2mortal(newSVpv(*argv,0)));
	    argv++;
	}
	PUTBACK;
    }
    return call_pv(sub_name, flags);
}

/*
=for apidoc p||call_pv

Performs a callback to the specified Perl sub.  See L<perlcall>.

=cut
*/

I32
Perl_call_pv(pTHX_ const char *sub_name, I32 flags)
              		/* name of the subroutine */
          		/* See G_* flags in cop.h */
{
    return call_sv((SV*)get_cv(sub_name, TRUE), flags);
}

/*
=for apidoc p||call_method

Performs a callback to the specified Perl method.  The blessed object must
be on the stack.  See L<perlcall>.

=cut
*/

I32
Perl_call_method(pTHX_ const char *methname, I32 flags)
               		/* name of the subroutine */
          		/* See G_* flags in cop.h */
{
    return call_sv(sv_2mortal(newSVpv(methname,0)), flags | G_METHOD);
}

/* May be called with any of a CV, a GV, or an SV containing the name. */
/*
=for apidoc p||call_sv

Performs a callback to the Perl sub whose name is in the SV.  See
L<perlcall>.

=cut
*/

I32
Perl_call_sv(pTHX_ SV *sv, I32 flags)
          		/* See G_* flags in cop.h */
{
    dSP;
    LOGOP myop;		/* fake syntax tree node */
    UNOP method_op;
    I32 oldmark;
    volatile I32 retval = 0;
    I32 oldscope;
    bool oldcatch = CATCH_GET;
    int ret;
    OP* oldop = PL_op;
    dJMPENV;

    if (flags & G_DISCARD) {
	ENTER;
	SAVETMPS;
    }

    Zero(&myop, 1, LOGOP);
    myop.op_next = Nullop;
    if (!(flags & G_NOARGS))
	myop.op_flags |= OPf_STACKED;
    myop.op_flags |= ((flags & G_VOID) ? OPf_WANT_VOID :
		      (flags & G_ARRAY) ? OPf_WANT_LIST :
		      OPf_WANT_SCALAR);
    SAVEOP();
    PL_op = (OP*)&myop;

    EXTEND(PL_stack_sp, 1);
    *++PL_stack_sp = sv;
    oldmark = TOPMARK;
    oldscope = PL_scopestack_ix;

    if (PERLDB_SUB && PL_curstash != PL_debstash
	   /* Handle first BEGIN of -d. */
	  && (PL_DBcv || (PL_DBcv = GvCV(PL_DBsub)))
	   /* Try harder, since this may have been a sighandler, thus
	    * curstash may be meaningless. */
	  && (SvTYPE(sv) != SVt_PVCV || CvSTASH((CV*)sv) != PL_debstash)
	  && !(flags & G_NODEBUG))
	PL_op->op_private |= OPpENTERSUB_DB;

    if (flags & G_METHOD) {
	Zero(&method_op, 1, UNOP);
	method_op.op_next = PL_op;
	method_op.op_ppaddr = PL_ppaddr[OP_METHOD];
	myop.op_ppaddr = PL_ppaddr[OP_ENTERSUB];
	PL_op = (OP*)&method_op;
    }

    if (!(flags & G_EVAL)) {
	CATCH_SET(TRUE);
	call_body((OP*)&myop, FALSE);
	retval = PL_stack_sp - (PL_stack_base + oldmark);
	CATCH_SET(oldcatch);
    }
    else {
	myop.op_other = (OP*)&myop;
	PL_markstack_ptr--;
	/* we're trying to emulate pp_entertry() here */
	{
	    register PERL_CONTEXT *cx;
	    I32 gimme = GIMME_V;
	
	    ENTER;
	    SAVETMPS;
	
	    PUSHBLOCK(cx, (CXt_EVAL|CXp_TRYBLOCK), PL_stack_sp);
	    PUSHEVAL(cx, 0, 0);
	    PL_eval_root = PL_op;             /* Only needed so that goto works right. */
	
	    PL_in_eval = EVAL_INEVAL;
	    if (flags & G_KEEPERR)
		PL_in_eval |= EVAL_KEEPERR;
	    else
		sv_setpv(ERRSV,"");
	}
	PL_markstack_ptr++;

#ifdef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
	CALLPROTECT(aTHX_ pcur_env, &ret, MEMBER_TO_FPTR(S_vcall_body),
		    (OP*)&myop, FALSE);
#else
	JMPENV_PUSH(ret);
#endif
	switch (ret) {
	case 0:
#ifndef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
	    call_body((OP*)&myop, FALSE);
#endif
	    retval = PL_stack_sp - (PL_stack_base + oldmark);
	    if (!(flags & G_KEEPERR))
		sv_setpv(ERRSV,"");
	    break;
	case 1:
	    STATUS_ALL_FAILURE;
	    /* FALL THROUGH */
	case 2:
	    /* my_exit() was called */
	    PL_curstash = PL_defstash;
	    FREETMPS;
	    JMPENV_POP;
	    if (PL_statusvalue && !(PL_exit_flags & PERL_EXIT_EXPECTED))
		Perl_croak(aTHX_ "Callback called exit");
	    my_exit_jump();
	    /* NOTREACHED */
	case 3:
	    if (PL_restartop) {
		PL_op = PL_restartop;
		PL_restartop = 0;
		goto redo_body;
	    }
	    PL_stack_sp = PL_stack_base + oldmark;
	    if (flags & G_ARRAY)
		retval = 0;
	    else {
		retval = 1;
		*++PL_stack_sp = &PL_sv_undef;
	    }
	    break;
	}

	if (PL_scopestack_ix > oldscope) {
	    SV **newsp;
	    PMOP *newpm;
	    I32 gimme;
	    register PERL_CONTEXT *cx;
	    I32 optype;

	    POPBLOCK(cx,newpm);
	    POPEVAL(cx);
	    PL_curpm = newpm;
	    LEAVE;
	}
	JMPENV_POP;
    }

    if (flags & G_DISCARD) {
	PL_stack_sp = PL_stack_base + oldmark;
	retval = 0;
	FREETMPS;
	LEAVE;
    }
    PL_op = oldop;
    return retval;
}

#ifdef PERL_FLEXIBLE_EXCEPTIONS
STATIC void *
S_vcall_body(pTHX_ va_list args)
{
    OP *myop = va_arg(args, OP*);
    int is_eval = va_arg(args, int);

    call_body(myop, is_eval);
    return NULL;
}
#endif

STATIC void
S_call_body(pTHX_ OP *myop, int is_eval)
{
    if (PL_op == myop) {
	if (is_eval)
	    PL_op = Perl_pp_entereval(aTHX);	/* this doesn't do a POPMARK */
	else
	    PL_op = Perl_pp_entersub(aTHX);	/* this does */
    }
    if (PL_op)
	CALLRUNOPS(aTHX);
}

/* Eval a string. The G_EVAL flag is always assumed. */

/*
=for apidoc p||eval_sv

Tells Perl to C<eval> the string in the SV.

=cut
*/

I32
Perl_eval_sv(pTHX_ SV *sv, I32 flags)

          		/* See G_* flags in cop.h */
{
    dSP;
    UNOP myop;		/* fake syntax tree node */
    volatile I32 oldmark = SP - PL_stack_base;
    volatile I32 retval = 0;
    I32 oldscope;
    int ret;
    OP* oldop = PL_op;
    dJMPENV;

    if (flags & G_DISCARD) {
	ENTER;
	SAVETMPS;
    }

    SAVEOP();
    PL_op = (OP*)&myop;
    Zero(PL_op, 1, UNOP);
    EXTEND(PL_stack_sp, 1);
    *++PL_stack_sp = sv;
    oldscope = PL_scopestack_ix;

    if (!(flags & G_NOARGS))
	myop.op_flags = OPf_STACKED;
    myop.op_next = Nullop;
    myop.op_type = OP_ENTEREVAL;
    myop.op_flags |= ((flags & G_VOID) ? OPf_WANT_VOID :
		      (flags & G_ARRAY) ? OPf_WANT_LIST :
		      OPf_WANT_SCALAR);
    if (flags & G_KEEPERR)
	myop.op_flags |= OPf_SPECIAL;

#ifdef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
    CALLPROTECT(aTHX_ pcur_env, &ret, MEMBER_TO_FPTR(S_vcall_body),
		(OP*)&myop, TRUE);
#else
    /* fail now; otherwise we could fail after the JMPENV_PUSH but
     * before a PUSHEVAL, which corrupts the stack after a croak */
    TAINT_PROPER("eval_sv()");

    JMPENV_PUSH(ret);
#endif
    switch (ret) {
    case 0:
#ifndef PERL_FLEXIBLE_EXCEPTIONS
 redo_body:
	call_body((OP*)&myop,TRUE);
#endif
	retval = PL_stack_sp - (PL_stack_base + oldmark);
	if (!(flags & G_KEEPERR))
	    sv_setpv(ERRSV,"");
	break;
    case 1:
	STATUS_ALL_FAILURE;
	/* FALL THROUGH */
    case 2:
	/* my_exit() was called */
	PL_curstash = PL_defstash;
	FREETMPS;
	JMPENV_POP;
	if (PL_statusvalue && !(PL_exit_flags & PERL_EXIT_EXPECTED))
	    Perl_croak(aTHX_ "Callback called exit");
	my_exit_jump();
	/* NOTREACHED */
    case 3:
	if (PL_restartop) {
	    PL_op = PL_restartop;
	    PL_restartop = 0;
	    goto redo_body;
	}
	PL_stack_sp = PL_stack_base + oldmark;
	if (flags & G_ARRAY)
	    retval = 0;
	else {
	    retval = 1;
	    *++PL_stack_sp = &PL_sv_undef;
	}
	break;
    }

    JMPENV_POP;
    if (flags & G_DISCARD) {
	PL_stack_sp = PL_stack_base + oldmark;
	retval = 0;
	FREETMPS;
	LEAVE;
    }
    PL_op = oldop;
    return retval;
}

/*
=for apidoc p||eval_pv

Tells Perl to C<eval> the given string and return an SV* result.

=cut
*/

SV*
Perl_eval_pv(pTHX_ const char *p, I32 croak_on_error)
{
    dSP;
    SV* sv = newSVpv(p, 0);

    eval_sv(sv, G_SCALAR);
    SvREFCNT_dec(sv);

    SPAGAIN;
    sv = POPs;
    PUTBACK;

    if (croak_on_error && SvTRUE(ERRSV)) {
	STRLEN n_a;
	Perl_croak(aTHX_ SvPVx(ERRSV, n_a));
    }

    return sv;
}

/* Require a module. */

/*
=head1 Embedding Functions

=for apidoc p||require_pv

Tells Perl to C<require> the file named by the string argument.  It is
analogous to the Perl code C<eval "require '$file'">.  It's even
implemented that way; consider using load_module instead.

=cut */

void
Perl_require_pv(pTHX_ const char *pv)
{
    SV* sv;
    dSP;
    PUSHSTACKi(PERLSI_REQUIRE);
    PUTBACK;
    sv = sv_newmortal();
    sv_setpv(sv, "require '");
    sv_catpv(sv, pv);
    sv_catpv(sv, "'");
    eval_sv(sv, G_DISCARD);
    SPAGAIN;
    POPSTACK;
}

void
Perl_magicname(pTHX_ char *sym, char *name, I32 namlen)
{
    register GV *gv;

    if ((gv = gv_fetchpv(sym,TRUE, SVt_PV)))
	sv_magic(GvSV(gv), (SV*)gv, PERL_MAGIC_sv, name, namlen);
}

STATIC void
S_usage(pTHX_ char *name)		/* XXX move this out into a module ? */
{
    /* This message really ought to be max 23 lines.
     * Removed -h because the user already knows that option. Others? */

    static char *usage_msg[] = {
"-0[octal]       specify record separator (\\0, if no argument)",
"-a              autosplit mode with -n or -p (splits $_ into @F)",
"-C[number/list] enables the listed Unicode features",
"-c              check syntax only (runs BEGIN and CHECK blocks)",
"-d[:debugger]   run program under debugger",
"-D[number/list] set debugging flags (argument is a bit mask or alphabets)",
"-e program      one line of program (several -e's allowed, omit programfile)",
"-F/pattern/     split() pattern for -a switch (//'s are optional)",
"-i[extension]   edit <> files in place (makes backup if extension supplied)",
"-Idirectory     specify @INC/#include directory (several -I's allowed)",
"-l[octal]       enable line ending processing, specifies line terminator",
"-[mM][-]module  execute `use/no module...' before executing program",
"-n              assume 'while (<>) { ... }' loop around program",
"-p              assume loop like -n but print line also, like sed",
"-P              run program through C preprocessor before compilation",
"-s              enable rudimentary parsing for switches after programfile",
"-S              look for programfile using PATH environment variable",
"-t              enable tainting warnings",
"-T              enable tainting checks",
"-u              dump core after parsing program",
"-U              allow unsafe operations",
"-v              print version, subversion (includes VERY IMPORTANT perl info)",
"-V[:variable]   print configuration summary (or a single Config.pm variable)",
"-w              enable many useful warnings (RECOMMENDED)",
"-W              enable all warnings",
"-x[directory]   strip off text before #!perl line and perhaps cd to directory",
"-X              disable all warnings",
"\n",
NULL
};
    char **p = usage_msg;

    PerlIO_printf(PerlIO_stdout(),
		  "\nUsage: %s [switches] [--] [programfile] [arguments]",
		  name);
    while (*p)
	PerlIO_printf(PerlIO_stdout(), "\n  %s", *p++);
}

/* convert a string of -D options (or digits) into an int.
 * sets *s to point to the char after the options */

#ifdef DEBUGGING
int
Perl_get_debug_opts(pTHX_ char **s, bool givehelp)
{
    static char *usage_msgd[] = {
      " Debugging flag values: (see also -d)",
      "  p  Tokenizing and parsing (with v, displays parse stack)",
      "  s  Stack snapshots (with v, displays all stacks)",
      "  l  Context (loop) stack processing",
      "  t  Trace execution",
      "  o  Method and overloading resolution",
      "  c  String/numeric conversions",
      "  P  Print profiling info, preprocessor command for -P, source file input state",
      "  m  Memory allocation",
      "  f  Format processing",
      "  r  Regular expression parsing and execution",
      "  x  Syntax tree dump",
      "  u  Tainting checks",
      "  H  Hash dump -- usurps values()",
      "  X  Scratchpad allocation",
      "  D  Cleaning up",
      "  S  Thread synchronization",
      "  T  Tokenising",
      "  R  Include reference counts of dumped variables (eg when using -Ds)",
      "  J  Do not s,t,P-debug (Jump over) opcodes within package DB",
      "  v  Verbose: use in conjunction with other flags",
      "  C  Copy On Write",
      "  A  Consistency checks on internal structures",
      "  q  quiet - currently only suppresses the 'EXECUTING' message",
      NULL
    };
    int i = 0;
    if (isALPHA(**s)) {
	/* if adding extra options, remember to update DEBUG_MASK */
	static char debopts[] = "psltocPmfrxu HXDSTRJvCAq";

	for (; isALNUM(**s); (*s)++) {
	    char *d = strchr(debopts,**s);
	    if (d)
		i |= 1 << (d - debopts);
	    else if (ckWARN_d(WARN_DEBUGGING))
	        Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
		    "invalid option -D%c, use -D'' to see choices\n", **s);
	}
    }
    else if (isDIGIT(**s)) {
	i = atoi(*s);
	for (; isALNUM(**s); (*s)++) ;
    }
    else if (givehelp) {
      char **p = usage_msgd;
      while (*p) PerlIO_printf(PerlIO_stdout(), "%s\n", *p++);
    }
#  ifdef EBCDIC
    if ((i & DEBUG_p_FLAG) && ckWARN_d(WARN_DEBUGGING))
	Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
		"-Dp not implemented on this platform\n");
#  endif
    return i;
}
#endif

/* This routine handles any switches that can be given during run */

char *
Perl_moreswitches(pTHX_ char *s)
{
    STRLEN numlen;
    UV rschar;

    switch (*s) {
    case '0':
    {
	 I32 flags = 0;

	 SvREFCNT_dec(PL_rs);
	 if (s[1] == 'x' && s[2]) {
	      char *e;
	      U8 *tmps;

	      for (s += 2, e = s; *e; e++);
	      numlen = e - s;
	      flags = PERL_SCAN_SILENT_ILLDIGIT;
	      rschar = (U32)grok_hex(s, &numlen, &flags, NULL);
	      if (s + numlen < e) {
		   rschar = 0; /* Grandfather -0xFOO as -0 -xFOO. */
		   numlen = 0;
		   s--;
	      }
	      PL_rs = newSVpvn("", 0);
	      SvGROW(PL_rs, (STRLEN)(UNISKIP(rschar) + 1));
	      tmps = (U8*)SvPVX(PL_rs);
	      uvchr_to_utf8(tmps, rschar);
	      SvCUR_set(PL_rs, UNISKIP(rschar));
	      SvUTF8_on(PL_rs);
	 }
	 else {
	      numlen = 4;
	      rschar = (U32)grok_oct(s, &numlen, &flags, NULL);
	      if (rschar & ~((U8)~0))
		   PL_rs = &PL_sv_undef;
	      else if (!rschar && numlen >= 2)
		   PL_rs = newSVpvn("", 0);
	      else {
		   char ch = (char)rschar;
		   PL_rs = newSVpvn(&ch, 1);
	      }
	 }
	 sv_setsv(get_sv("/", TRUE), PL_rs);
	 return s + numlen;
    }
    case 'C':
        s++;
        PL_unicode = parse_unicode_opts(&s);
	return s;
    case 'F':
	PL_minus_F = TRUE;
	PL_splitstr = ++s;
	while (*s && !isSPACE(*s)) ++s;
	*s = '\0';
	PL_splitstr = savepv(PL_splitstr);
	return s;
    case 'a':
	PL_minus_a = TRUE;
	s++;
	return s;
    case 'c':
	PL_minus_c = TRUE;
	s++;
	return s;
    case 'd':
	forbid_setid("-d");
	s++;

        /* -dt indicates to the debugger that threads will be used */
	if (*s == 't' && !isALNUM(s[1])) {
	    ++s;
	    my_setenv("PERL5DB_THREADED", "1");
	}

	/* The following permits -d:Mod to accepts arguments following an =
	   in the fashion that -MSome::Mod does. */
	if (*s == ':' || *s == '=') {
	    char *start;
	    SV *sv;
	    sv = newSVpv("use Devel::", 0);
	    start = ++s;
	    /* We now allow -d:Module=Foo,Bar */
	    while(isALNUM(*s) || *s==':') ++s;
	    if (*s != '=')
		sv_catpv(sv, start);
	    else {
		sv_catpvn(sv, start, s-start);
		sv_catpv(sv, " split(/,/,q{");
		sv_catpv(sv, ++s);
		sv_catpv(sv, "})");
	    }
	    s += strlen(s);
	    my_setenv("PERL5DB", SvPV(sv, PL_na));
	}
	if (!PL_perldb) {
	    PL_perldb = PERLDB_ALL;
	    init_debugger();
	}
	return s;
    case 'D':
    {	
#ifdef DEBUGGING
	forbid_setid("-D");
	s++;
	PL_debug = get_debug_opts(&s, 1) | DEBUG_TOP_FLAG;
#else /* !DEBUGGING */
	if (ckWARN_d(WARN_DEBUGGING))
	    Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
	           "Recompile perl with -DDEBUGGING to use -D switch (did you mean -d ?)\n");
	for (s++; isALNUM(*s); s++) ;
#endif
	/*SUPPRESS 530*/
	return s;
    }	
    case 'h':
	usage(PL_origargv[0]);
	my_exit(0);
    case 'i':
	if (PL_inplace)
	    Safefree(PL_inplace);
#if defined(__CYGWIN__) /* do backup extension automagically */
	if (*(s+1) == '\0') {
	PL_inplace = savepv(".bak");
	return s+1;
	}
#endif /* __CYGWIN__ */
	PL_inplace = savepv(s+1);
	/*SUPPRESS 530*/
	for (s = PL_inplace; *s && !isSPACE(*s); s++) ;
	if (*s) {
	    *s++ = '\0';
	    if (*s == '-')	/* Additional switches on #! line. */
	        s++;
	}
	return s;
    case 'I':	/* -I handled both here and in parse_body() */
	forbid_setid("-I");
	++s;
	while (*s && isSPACE(*s))
	    ++s;
	if (*s) {
	    char *e, *p;
	    p = s;
	    /* ignore trailing spaces (possibly followed by other switches) */
	    do {
		for (e = p; *e && !isSPACE(*e); e++) ;
		p = e;
		while (isSPACE(*p))
		    p++;
	    } while (*p && *p != '-');
	    e = savepvn(s, e-s);
	    incpush(e, TRUE, TRUE, FALSE);
	    Safefree(e);
	    s = p;
	    if (*s == '-')
		s++;
	}
	else
	    Perl_croak(aTHX_ "No directory specified for -I");
	return s;
    case 'l':
	PL_minus_l = TRUE;
	s++;
	if (PL_ors_sv) {
	    SvREFCNT_dec(PL_ors_sv);
	    PL_ors_sv = Nullsv;
	}
	if (isDIGIT(*s)) {
            I32 flags = 0;
	    PL_ors_sv = newSVpvn("\n",1);
	    numlen = 3 + (*s == '0');
	    *SvPVX(PL_ors_sv) = (char)grok_oct(s, &numlen, &flags, NULL);
	    s += numlen;
	}
	else {
	    if (RsPARA(PL_rs)) {
		PL_ors_sv = newSVpvn("\n\n",2);
	    }
	    else {
		PL_ors_sv = newSVsv(PL_rs);
	    }
	}
	return s;
    case 'A':
	forbid_setid("-A");
	if (!PL_preambleav)
	    PL_preambleav = newAV();
	if (*++s) {
	    SV *sv = newSVpv("use assertions::activate split(/,/,q", 0);
	    sv_catpvn(sv, "\0", 1);     /* Use NUL as q//-delimiter. */
	    sv_catpv(sv,s);
	    sv_catpvn(sv, "\0)", 2);
	    s+=strlen(s);
	    av_push(PL_preambleav, sv);
	}
	else
	    av_push(PL_preambleav, newSVpvn("use assertions::activate",24));
	return s;
    case 'M':
	forbid_setid("-M");	/* XXX ? */
	/* FALL THROUGH */
    case 'm':
	forbid_setid("-m");	/* XXX ? */
	if (*++s) {
	    char *start;
	    SV *sv;
	    char *use = "use ";
	    /* -M-foo == 'no foo'	*/
	    if (*s == '-') { use = "no "; ++s; }
	    sv = newSVpv(use,0);
	    start = s;
	    /* We allow -M'Module qw(Foo Bar)'	*/
	    while(isALNUM(*s) || *s==':') ++s;
	    if (*s != '=') {
		sv_catpv(sv, start);
		if (*(start-1) == 'm') {
		    if (*s != '\0')
			Perl_croak(aTHX_ "Can't use '%c' after -mname", *s);
		    sv_catpv( sv, " ()");
		}
	    } else {
                if (s == start)
                    Perl_croak(aTHX_ "Module name required with -%c option",
			       s[-1]);
		sv_catpvn(sv, start, s-start);
		sv_catpv(sv, " split(/,/,q");
		sv_catpvn(sv, "\0)", 1);        /* Use NUL as q//-delimiter. */
		sv_catpv(sv, ++s);
		sv_catpvn(sv,  "\0)", 2);
	    }
	    s += strlen(s);
	    if (!PL_preambleav)
		PL_preambleav = newAV();
	    av_push(PL_preambleav, sv);
	}
	else
	    Perl_croak(aTHX_ "Missing argument to -%c", *(s-1));
	return s;
    case 'n':
	PL_minus_n = TRUE;
	s++;
	return s;
    case 'p':
	PL_minus_p = TRUE;
	s++;
	return s;
    case 's':
	forbid_setid("-s");
	PL_doswitches = TRUE;
	s++;
	return s;
    case 't':
        if (!PL_tainting)
	    TOO_LATE_FOR('t');
        s++;
        return s;
    case 'T':
	if (!PL_tainting)
	    TOO_LATE_FOR('T');
	s++;
	return s;
    case 'u':
#ifdef MACOS_TRADITIONAL
	Perl_croak(aTHX_ "Believe me, you don't want to use \"-u\" on a Macintosh");
#endif
	PL_do_undump = TRUE;
	s++;
	return s;
    case 'U':
	PL_unsafe = TRUE;
	s++;
	return s;
    case 'v':
	if (!sv_derived_from(PL_patchlevel, "version"))
		(void *)upg_version(PL_patchlevel);
#if !defined(DGUX)
	PerlIO_printf(PerlIO_stdout(),
		Perl_form(aTHX_ "\nThis is perl, v%_ built for %s",
		    vstringify(PL_patchlevel),
		    ARCHNAME));
#else /* DGUX */
/* Adjust verbose output as in the perl that ships with the DG/UX OS from EMC */
	PerlIO_printf(PerlIO_stdout(),
		Perl_form(aTHX_ "\nThis is perl, v%_\n",
		    vstringify(PL_patchlevel)));
	PerlIO_printf(PerlIO_stdout(),
			Perl_form(aTHX_ "        built under %s at %s %s\n",
					OSNAME, __DATE__, __TIME__));
	PerlIO_printf(PerlIO_stdout(),
			Perl_form(aTHX_ "        OS Specific Release: %s\n",
					OSVERS));
#endif /* !DGUX */

#if defined(LOCAL_PATCH_COUNT)
	if (LOCAL_PATCH_COUNT > 0)
	    PerlIO_printf(PerlIO_stdout(),
			  "\n(with %d registered patch%s, "
			  "see perl -V for more detail)",
			  (int)LOCAL_PATCH_COUNT,
			  (LOCAL_PATCH_COUNT!=1) ? "es" : "");
#endif

	PerlIO_printf(PerlIO_stdout(),
		      "\n\nCopyright 1987-2004, Larry Wall\n");
#ifdef MACOS_TRADITIONAL
	PerlIO_printf(PerlIO_stdout(),
		      "\nMac OS port Copyright 1991-2002, Matthias Neeracher;\n"
		      "maintained by Chris Nandor\n");
#endif
#ifdef MSDOS
	PerlIO_printf(PerlIO_stdout(),
		      "\nMS-DOS port Copyright (c) 1989, 1990, Diomidis Spinellis\n");
#endif
#ifdef DJGPP
	PerlIO_printf(PerlIO_stdout(),
		      "djgpp v2 port (jpl5003c) by Hirofumi Watanabe, 1996\n"
		      "djgpp v2 port (perl5004+) by Laszlo Molnar, 1997-1999\n");
#endif
#ifdef OS2
	PerlIO_printf(PerlIO_stdout(),
		      "\n\nOS/2 port Copyright (c) 1990, 1991, Raymond Chen, Kai Uwe Rommel\n"
		      "Version 5 port Copyright (c) 1994-2002, Andreas Kaiser, Ilya Zakharevich\n");
#endif
#ifdef atarist
	PerlIO_printf(PerlIO_stdout(),
		      "atariST series port, ++jrb  bammi@cadence.com\n");
#endif
#ifdef __BEOS__
	PerlIO_printf(PerlIO_stdout(),
		      "BeOS port Copyright Tom Spindler, 1997-1999\n");
#endif
#ifdef MPE
	PerlIO_printf(PerlIO_stdout(),
		      "MPE/iX port Copyright by Mark Klein and Mark Bixby, 1996-2003\n");
#endif
#ifdef OEMVS
	PerlIO_printf(PerlIO_stdout(),
		      "MVS (OS390) port by Mortice Kern Systems, 1997-1999\n");
#endif
#ifdef __VOS__
	PerlIO_printf(PerlIO_stdout(),
		      "Stratus VOS port by Paul.Green@stratus.com, 1997-2002\n");
#endif
#ifdef __OPEN_VM
	PerlIO_printf(PerlIO_stdout(),
		      "VM/ESA port by Neale Ferguson, 1998-1999\n");
#endif
#ifdef POSIX_BC
	PerlIO_printf(PerlIO_stdout(),
		      "BS2000 (POSIX) port by Start Amadeus GmbH, 1998-1999\n");
#endif
#ifdef __MINT__
	PerlIO_printf(PerlIO_stdout(),
		      "MiNT port by Guido Flohr, 1997-1999\n");
#endif
#ifdef EPOC
	PerlIO_printf(PerlIO_stdout(),
		      "EPOC port by Olaf Flebbe, 1999-2002\n");
#endif
#ifdef UNDER_CE
	PerlIO_printf(PerlIO_stdout(),"WINCE port by Rainer Keuchel, 2001-2002\n");
	PerlIO_printf(PerlIO_stdout(),"Built on " __DATE__ " " __TIME__ "\n\n");
	wce_hitreturn();
#endif
#ifdef BINARY_BUILD_NOTICE
	BINARY_BUILD_NOTICE;
#endif
	PerlIO_printf(PerlIO_stdout(),
		      "\n\
Perl may be copied only under the terms of either the Artistic License or the\n\
GNU General Public License, which may be found in the Perl 5 source kit.\n\n\
Complete documentation for Perl, including FAQ lists, should be found on\n\
this system using `man perl' or `perldoc perl'.  If you have access to the\n\
Internet, point your browser at http://www.perl.org/, the Perl Home Page.\n\n");
	my_exit(0);
    case 'w':
	if (! (PL_dowarn & G_WARN_ALL_MASK))
	    PL_dowarn |= G_WARN_ON;
	s++;
	return s;
    case 'W':
	PL_dowarn = G_WARN_ALL_ON|G_WARN_ON;
        if (!specialWARN(PL_compiling.cop_warnings))
            SvREFCNT_dec(PL_compiling.cop_warnings);
	PL_compiling.cop_warnings = pWARN_ALL ;
	s++;
	return s;
    case 'X':
	PL_dowarn = G_WARN_ALL_OFF;
        if (!specialWARN(PL_compiling.cop_warnings))
            SvREFCNT_dec(PL_compiling.cop_warnings);
	PL_compiling.cop_warnings = pWARN_NONE ;
	s++;
	return s;
    case '*':
    case ' ':
	if (s[1] == '-')	/* Additional switches on #! line. */
	    return s+2;
	break;
    case '-':
    case 0:
#if defined(WIN32) || !defined(PERL_STRICT_CR)
    case '\r':
#endif
    case '\n':
    case '\t':
	break;
#ifdef ALTERNATE_SHEBANG
    case 'S':			/* OS/2 needs -S on "extproc" line. */
	break;
#endif
    case 'P':
	if (PL_preprocess)
	    return s+1;
	/* FALL THROUGH */
    default:
	Perl_croak(aTHX_ "Can't emulate -%.1s on #! line",s);
    }
    return Nullch;
}

/* compliments of Tom Christiansen */

/* unexec() can be found in the Gnu emacs distribution */
/* Known to work with -DUNEXEC and using unexelf.c from GNU emacs-20.2 */

void
Perl_my_unexec(pTHX)
{
#ifdef UNEXEC
    SV*    prog;
    SV*    file;
    int    status = 1;
    extern int etext;

    prog = newSVpv(BIN_EXP, 0);
    sv_catpv(prog, "/perl");
    file = newSVpv(PL_origfilename, 0);
    sv_catpv(file, ".perldump");

    unexec(SvPVX(file), SvPVX(prog), &etext, sbrk(0), 0);
    /* unexec prints msg to stderr in case of failure */
    PerlProc_exit(status);
#else
#  ifdef VMS
#    include <lib$routines.h>
     lib$signal(SS$_DEBUG);  /* ssdef.h #included from vmsish.h */
#  else
    ABORT();		/* for use with undump */
#  endif
#endif
}

/* initialize curinterp */
STATIC void
S_init_interp(pTHX)
{

#ifdef MULTIPLICITY
#  define PERLVAR(var,type)
#  define PERLVARA(var,n,type)
#  if defined(PERL_IMPLICIT_CONTEXT)
#    if defined(USE_5005THREADS)
#      define PERLVARI(var,type,init)		PERL_GET_INTERP->var = init;
#      define PERLVARIC(var,type,init)	PERL_GET_INTERP->var = init;
#    else /* !USE_5005THREADS */
#      define PERLVARI(var,type,init)		aTHX->var = init;
#      define PERLVARIC(var,type,init)	aTHX->var = init;
#    endif /* USE_5005THREADS */
#  else
#    define PERLVARI(var,type,init)	PERL_GET_INTERP->var = init;
#    define PERLVARIC(var,type,init)	PERL_GET_INTERP->var = init;
#  endif
#  include "intrpvar.h"
#  ifndef USE_5005THREADS
#    include "thrdvar.h"
#  endif
#  undef PERLVAR
#  undef PERLVARA
#  undef PERLVARI
#  undef PERLVARIC
#else
#  define PERLVAR(var,type)
#  define PERLVARA(var,n,type)
#  define PERLVARI(var,type,init)	PL_##var = init;
#  define PERLVARIC(var,type,init)	PL_##var = init;
#  include "intrpvar.h"
#  ifndef USE_5005THREADS
#    include "thrdvar.h"
#  endif
#  undef PERLVAR
#  undef PERLVARA
#  undef PERLVARI
#  undef PERLVARIC
#endif

}

STATIC void
S_init_main_stash(pTHX)
{
    GV *gv;

    PL_curstash = PL_defstash = newHV();
    PL_curstname = newSVpvn("main",4);
    gv = gv_fetchpv("main::",TRUE, SVt_PVHV);
    SvREFCNT_dec(GvHV(gv));
    GvHV(gv) = (HV*)SvREFCNT_inc(PL_defstash);
    SvREADONLY_on(gv);
    HvNAME(PL_defstash) = savepv("main");
    PL_incgv = gv_HVadd(gv_AVadd(gv_fetchpv("INC",TRUE, SVt_PVAV)));
    GvMULTI_on(PL_incgv);
    PL_hintgv = gv_fetchpv("\010",TRUE, SVt_PV); /* ^H */
    GvMULTI_on(PL_hintgv);
    PL_defgv = gv_fetchpv("_",TRUE, SVt_PVAV);
    PL_errgv = gv_HVadd(gv_fetchpv("@", TRUE, SVt_PV));
    GvMULTI_on(PL_errgv);
    PL_replgv = gv_fetchpv("\022", TRUE, SVt_PV); /* ^R */
    GvMULTI_on(PL_replgv);
    (void)Perl_form(aTHX_ "%240s","");	/* Preallocate temp - for immediate signals. */
    sv_grow(ERRSV, 240);	/* Preallocate - for immediate signals. */
    sv_setpvn(ERRSV, "", 0);
    PL_curstash = PL_defstash;
    CopSTASH_set(&PL_compiling, PL_defstash);
    PL_debstash = GvHV(gv_fetchpv("DB::", GV_ADDMULTI, SVt_PVHV));
    PL_globalstash = GvHV(gv_fetchpv("CORE::GLOBAL::", GV_ADDMULTI, SVt_PVHV));
    /* We must init $/ before switches are processed. */
    sv_setpvn(get_sv("/", TRUE), "\n", 1);
}

/* PSz 18 Nov 03  fdscript now global but do not change prototype */
STATIC void
S_open_script(pTHX_ char *scriptname, bool dosearch, SV *sv)
{
#ifndef IAMSUID
    char *quote;
    char *code;
    char *cpp_discard_flag;
    char *perl;
#endif

    PL_fdscript = -1;
    PL_suidscript = -1;

    if (PL_e_script) {
	PL_origfilename = savepv("-e");
    }
    else {
	/* if find_script() returns, it returns a malloc()-ed value */
	PL_origfilename = scriptname = find_script(scriptname, dosearch, NULL, 1);

	if (strnEQ(scriptname, "/dev/fd/", 8) && isDIGIT(scriptname[8]) ) {
	    char *s = scriptname + 8;
	    PL_fdscript = atoi(s);
	    while (isDIGIT(*s))
		s++;
	    if (*s) {
		/* PSz 18 Feb 04
		 * Tell apart "normal" usage of fdscript, e.g.
		 * with bash on FreeBSD:
		 *   perl <( echo '#!perl -DA'; echo 'print "$0\n"')
		 * from usage in suidperl.
		 * Does any "normal" usage leave garbage after the number???
		 * Is it a mistake to use a similar /dev/fd/ construct for
		 * suidperl?
		 */
		PL_suidscript = 1;
		/* PSz 20 Feb 04  
		 * Be supersafe and do some sanity-checks.
		 * Still, can we be sure we got the right thing?
		 */
		if (*s != '/') {
		    Perl_croak(aTHX_ "Wrong syntax (suid) fd script name \"%s\"\n", s);
		}
		if (! *(s+1)) {
		    Perl_croak(aTHX_ "Missing (suid) fd script name\n");
		}
		scriptname = savepv(s + 1);
		Safefree(PL_origfilename);
		PL_origfilename = scriptname;
	    }
	}
    }

    CopFILE_free(PL_curcop);
    CopFILE_set(PL_curcop, PL_origfilename);
    if (strEQ(PL_origfilename,"-"))
	scriptname = "";
    if (PL_fdscript >= 0) {
	PL_rsfp = PerlIO_fdopen(PL_fdscript,PERL_SCRIPT_MODE);
#       if defined(HAS_FCNTL) && defined(F_SETFD)
	    if (PL_rsfp)
                /* ensure close-on-exec */
	        fcntl(PerlIO_fileno(PL_rsfp),F_SETFD,1);
#       endif
    }
#ifdef IAMSUID
    else {
	Perl_croak(aTHX_ "sperl needs fd script\n"
		   "You should not call sperl directly; do you need to "
		   "change a #! line\nfrom sperl to perl?\n");

/* PSz 11 Nov 03
 * Do not open (or do other fancy stuff) while setuid.
 * Perl does the open, and hands script to suidperl on a fd;
 * suidperl only does some checks, sets up UIDs and re-execs
 * perl with that fd as it has always done.
 */
    }
    if (PL_suidscript != 1) {
	Perl_croak(aTHX_ "suidperl needs (suid) fd script\n");
    }
#else /* IAMSUID */
    else if (PL_preprocess) {
	char *cpp_cfg = CPPSTDIN;
	SV *cpp = newSVpvn("",0);
	SV *cmd = NEWSV(0,0);

	if (cpp_cfg[0] == 0) /* PERL_MICRO? */
	     Perl_croak(aTHX_ "Can't run with cpp -P with CPPSTDIN undefined");
	if (strEQ(cpp_cfg, "cppstdin"))
	    Perl_sv_catpvf(aTHX_ cpp, "%s/", BIN_EXP);
	sv_catpv(cpp, cpp_cfg);

#       ifndef VMS
	    sv_catpvn(sv, "-I", 2);
	    sv_catpv(sv,PRIVLIB_EXP);
#       endif

	DEBUG_P(PerlIO_printf(Perl_debug_log,
			      "PL_preprocess: scriptname=\"%s\", cpp=\"%s\", sv=\"%s\", CPPMINUS=\"%s\"\n",
			      scriptname, SvPVX (cpp), SvPVX (sv), CPPMINUS));

#       if defined(MSDOS) || defined(WIN32) || defined(VMS)
            quote = "\"";
#       else
            quote = "'";
#       endif

#       ifdef VMS
            cpp_discard_flag = "";
#       else
            cpp_discard_flag = "-C";
#       endif

#       ifdef OS2
            perl = os2_execname(aTHX);
#       else
            perl = PL_origargv[0];
#       endif


        /* This strips off Perl comments which might interfere with
           the C pre-processor, including #!.  #line directives are
           deliberately stripped to avoid confusion with Perl's version
           of #line.  FWP played some golf with it so it will fit
           into VMS's 255 character buffer.
        */
        if( PL_doextract )
            code = "(1../^#!.*perl/i)|/^\\s*#(?!\\s*((ifn?|un)def|(el|end)?if|define|include|else|error|pragma)\\b)/||!($|=1)||print";
        else
            code = "/^\\s*#(?!\\s*((ifn?|un)def|(el|end)?if|define|include|else|error|pragma)\\b)/||!($|=1)||print";

        Perl_sv_setpvf(aTHX_ cmd, "\
%s -ne%s%s%s %s | %"SVf" %s %"SVf" %s",
                       perl, quote, code, quote, scriptname, cpp,
                       cpp_discard_flag, sv, CPPMINUS);

	PL_doextract = FALSE;

        DEBUG_P(PerlIO_printf(Perl_debug_log,
                              "PL_preprocess: cmd=\"%s\"\n",
                              SvPVX(cmd)));

	PL_rsfp = PerlProc_popen(SvPVX(cmd), "r");
	SvREFCNT_dec(cmd);
	SvREFCNT_dec(cpp);
    }
    else if (!*scriptname) {
	forbid_setid("program input from stdin");
	PL_rsfp = PerlIO_stdin();
    }
    else {
	PL_rsfp = PerlIO_open(scriptname,PERL_SCRIPT_MODE);
#       if defined(HAS_FCNTL) && defined(F_SETFD)
	    if (PL_rsfp)
                /* ensure close-on-exec */
	        fcntl(PerlIO_fileno(PL_rsfp),F_SETFD,1);
#       endif
    }
#endif /* IAMSUID */
    if (!PL_rsfp) {
	/* PSz 16 Sep 03  Keep neat error message */
	Perl_croak(aTHX_ "Can't open perl script \"%s\": %s\n",
		CopFILE(PL_curcop), Strerror(errno));
    }
}

/* Mention
 * I_SYSSTATVFS	HAS_FSTATVFS
 * I_SYSMOUNT
 * I_STATFS	HAS_FSTATFS	HAS_GETFSSTAT
 * I_MNTENT	HAS_GETMNTENT	HAS_HASMNTOPT
 * here so that metaconfig picks them up. */

#ifdef IAMSUID
STATIC int
S_fd_on_nosuid_fs(pTHX_ int fd)
{
/* PSz 27 Feb 04
 * We used to do this as "plain" user (after swapping UIDs with setreuid);
 * but is needed also on machines without setreuid.
 * Seems safe enough to run as root.
 */
    int check_okay = 0; /* able to do all the required sys/libcalls */
    int on_nosuid  = 0; /* the fd is on a nosuid fs */
    /* PSz 12 Nov 03
     * Need to check noexec also: nosuid might not be set, the average
     * sysadmin would say that nosuid is irrelevant once he sets noexec.
     */
    int on_noexec  = 0; /* the fd is on a noexec fs */

/*
 * Preferred order: fstatvfs(), fstatfs(), ustat()+getmnt(), getmntent().
 * fstatvfs() is UNIX98.
 * fstatfs() is 4.3 BSD.
 * ustat()+getmnt() is pre-4.3 BSD.
 * getmntent() is O(number-of-mounted-filesystems) and can hang on
 * an irrelevant filesystem while trying to reach the right one.
 */

#undef FD_ON_NOSUID_CHECK_OKAY  /* found the syscalls to do the check? */

#   if !defined(FD_ON_NOSUID_CHECK_OKAY) && \
        defined(HAS_FSTATVFS)
#   define FD_ON_NOSUID_CHECK_OKAY
    struct statvfs stfs;

    check_okay = fstatvfs(fd, &stfs) == 0;
    on_nosuid  = check_okay && (stfs.f_flag  & ST_NOSUID);
#ifdef ST_NOEXEC
    /* ST_NOEXEC certainly absent on AIX 5.1, and doesn't seem to be documented
       on platforms where it is present.  */
    on_noexec  = check_okay && (stfs.f_flag  & ST_NOEXEC);
#endif
#   endif /* fstatvfs */

#   if !defined(FD_ON_NOSUID_CHECK_OKAY) && \
        defined(PERL_MOUNT_NOSUID)	&& \
        defined(PERL_MOUNT_NOEXEC)	&& \
        defined(HAS_FSTATFS) 		&& \
        defined(HAS_STRUCT_STATFS)	&& \
        defined(HAS_STRUCT_STATFS_F_FLAGS)
#   define FD_ON_NOSUID_CHECK_OKAY
    struct statfs  stfs;

    check_okay = fstatfs(fd, &stfs)  == 0;
    on_nosuid  = check_okay && (stfs.f_flags & PERL_MOUNT_NOSUID);
    on_noexec  = check_okay && (stfs.f_flags & PERL_MOUNT_NOEXEC);
#   endif /* fstatfs */

#   if !defined(FD_ON_NOSUID_CHECK_OKAY) && \
        defined(PERL_MOUNT_NOSUID)	&& \
        defined(PERL_MOUNT_NOEXEC)	&& \
        defined(HAS_FSTAT)		&& \
        defined(HAS_USTAT)		&& \
        defined(HAS_GETMNT)		&& \
        defined(HAS_STRUCT_FS_DATA)	&& \
        defined(NOSTAT_ONE)
#   define FD_ON_NOSUID_CHECK_OKAY
    Stat_t fdst;

    if (fstat(fd, &fdst) == 0) {
        struct ustat us;
        if (ustat(fdst.st_dev, &us) == 0) {
            struct fs_data fsd;
            /* NOSTAT_ONE here because we're not examining fields which
             * vary between that case and STAT_ONE. */
            if (getmnt((int*)0, &fsd, (int)0, NOSTAT_ONE, us.f_fname) == 0) {
                size_t cmplen = sizeof(us.f_fname);
                if (sizeof(fsd.fd_req.path) < cmplen)
                    cmplen = sizeof(fsd.fd_req.path);
                if (strnEQ(fsd.fd_req.path, us.f_fname, cmplen) &&
                    fdst.st_dev == fsd.fd_req.dev) {
                        check_okay = 1;
                        on_nosuid = fsd.fd_req.flags & PERL_MOUNT_NOSUID;
                        on_noexec = fsd.fd_req.flags & PERL_MOUNT_NOEXEC;
                    }
                }
            }
        }
    }
#   endif /* fstat+ustat+getmnt */

#   if !defined(FD_ON_NOSUID_CHECK_OKAY) && \
        defined(HAS_GETMNTENT)		&& \
        defined(HAS_HASMNTOPT)		&& \
        defined(MNTOPT_NOSUID)		&& \
        defined(MNTOPT_NOEXEC)
#   define FD_ON_NOSUID_CHECK_OKAY
    FILE                *mtab = fopen("/etc/mtab", "r");
    struct mntent       *entry;
    Stat_t              stb, fsb;

    if (mtab && (fstat(fd, &stb) == 0)) {
        while (entry = getmntent(mtab)) {
            if (stat(entry->mnt_dir, &fsb) == 0
                && fsb.st_dev == stb.st_dev)
            {
                /* found the filesystem */
                check_okay = 1;
                if (hasmntopt(entry, MNTOPT_NOSUID))
                    on_nosuid = 1;
                if (hasmntopt(entry, MNTOPT_NOEXEC))
                    on_noexec = 1;
                break;
            } /* A single fs may well fail its stat(). */
        }
    }
    if (mtab)
        fclose(mtab);
#   endif /* getmntent+hasmntopt */

    if (!check_okay)
	Perl_croak(aTHX_ "Can't check filesystem of script \"%s\" for nosuid/noexec", PL_origfilename);
    if (on_nosuid)
	Perl_croak(aTHX_ "Setuid script \"%s\" on nosuid filesystem", PL_origfilename);
    if (on_noexec)
	Perl_croak(aTHX_ "Setuid script \"%s\" on noexec filesystem", PL_origfilename);
    return ((!check_okay) || on_nosuid || on_noexec);
}
#endif /* IAMSUID */

STATIC void
S_validate_suid(pTHX_ char *validarg, char *scriptname)
{
#ifdef IAMSUID
    /* int which; */
#endif /* IAMSUID */

    /* do we need to emulate setuid on scripts? */

    /* This code is for those BSD systems that have setuid #! scripts disabled
     * in the kernel because of a security problem.  Merely defining DOSUID
     * in perl will not fix that problem, but if you have disabled setuid
     * scripts in the kernel, this will attempt to emulate setuid and setgid
     * on scripts that have those now-otherwise-useless bits set.  The setuid
     * root version must be called suidperl or sperlN.NNN.  If regular perl
     * discovers that it has opened a setuid script, it calls suidperl with
     * the same argv that it had.  If suidperl finds that the script it has
     * just opened is NOT setuid root, it sets the effective uid back to the
     * uid.  We don't just make perl setuid root because that loses the
     * effective uid we had before invoking perl, if it was different from the
     * uid.
     * PSz 27 Feb 04
     * Description/comments above do not match current workings:
     *   suidperl must be hardlinked to sperlN.NNN (that is what we exec);
     *   suidperl called with script open and name changed to /dev/fd/N/X;
     *   suidperl croaks if script is not setuid;
     *   making perl setuid would be a huge security risk (and yes, that
     *     would lose any euid we might have had).
     *
     * DOSUID must be defined in both perl and suidperl, and IAMSUID must
     * be defined in suidperl only.  suidperl must be setuid root.  The
     * Configure script will set this up for you if you want it.
     */

#ifdef DOSUID
    char *s, *s2;

    if (PerlLIO_fstat(PerlIO_fileno(PL_rsfp),&PL_statbuf) < 0)	/* normal stat is insecure */
	Perl_croak(aTHX_ "Can't stat script \"%s\"",PL_origfilename);
    if (PL_statbuf.st_mode & (S_ISUID|S_ISGID)) {
	I32 len;
	STRLEN n_a;

#ifdef IAMSUID
	if (PL_fdscript < 0 || PL_suidscript != 1)
	    Perl_croak(aTHX_ "Need (suid) fdscript in suidperl\n");	/* We already checked this */
	/* PSz 11 Nov 03
	 * Since the script is opened by perl, not suidperl, some of these
	 * checks are superfluous. Leaving them in probably does not lower
	 * security(?!).
	 */
	/* PSz 27 Feb 04
	 * Do checks even for systems with no HAS_SETREUID.
	 * We used to swap, then re-swap UIDs with
#ifdef HAS_SETREUID
	    if (setreuid(PL_euid,PL_uid) < 0
		|| PerlProc_getuid() != PL_euid || PerlProc_geteuid() != PL_uid)
		Perl_croak(aTHX_ "Can't swap uid and euid");
#endif
#ifdef HAS_SETREUID
	    if (setreuid(PL_uid,PL_euid) < 0
		|| PerlProc_getuid() != PL_uid || PerlProc_geteuid() != PL_euid)
		Perl_croak(aTHX_ "Can't reswap uid and euid");
#endif
	 */

	/* On this access check to make sure the directories are readable,
	 * there is actually a small window that the user could use to make
	 * filename point to an accessible directory.  So there is a faint
	 * chance that someone could execute a setuid script down in a
	 * non-accessible directory.  I don't know what to do about that.
	 * But I don't think it's too important.  The manual lies when
	 * it says access() is useful in setuid programs.
	 * 
	 * So, access() is pretty useless... but not harmful... do anyway.
	 */
	if (PerlLIO_access(CopFILE(PL_curcop),1)) { /*double check*/
	    Perl_croak(aTHX_ "Can't access() script\n");
	}

	/* If we can swap euid and uid, then we can determine access rights
	 * with a simple stat of the file, and then compare device and
	 * inode to make sure we did stat() on the same file we opened.
	 * Then we just have to make sure he or she can execute it.
	 * 
	 * PSz 24 Feb 04
	 * As the script is opened by perl, not suidperl, we do not need to
	 * care much about access rights.
	 * 
	 * The 'script changed' check is needed, or we can get lied to
	 * about $0 with e.g.
	 *  suidperl /dev/fd/4//bin/x 4<setuidscript
	 * Without HAS_SETREUID, is it safe to stat() as root?
	 * 
	 * Are there any operating systems that pass /dev/fd/xxx for setuid
	 * scripts, as suggested/described in perlsec(1)? Surely they do not
	 * pass the script name as we do, so the "script changed" test would
	 * fail for them... but we never get here with
	 * SETUID_SCRIPTS_ARE_SECURE_NOW defined.
	 * 
	 * This is one place where we must "lie" about return status: not
	 * say if the stat() failed. We are doing this as root, and could
	 * be tricked into reporting existence or not of files that the
	 * "plain" user cannot even see.
	 */
	{
	    Stat_t tmpstatbuf;
	    if (PerlLIO_stat(CopFILE(PL_curcop),&tmpstatbuf) < 0 ||
		tmpstatbuf.st_dev != PL_statbuf.st_dev ||
		tmpstatbuf.st_ino != PL_statbuf.st_ino) {
		Perl_croak(aTHX_ "Setuid script changed\n");
	    }

	}
	if (!cando(S_IXUSR,FALSE,&PL_statbuf))		/* can real uid exec? */
	    Perl_croak(aTHX_ "Real UID cannot exec script\n");

	/* PSz 27 Feb 04
	 * We used to do this check as the "plain" user (after swapping
	 * UIDs). But the check for nosuid and noexec filesystem is needed,
	 * and should be done even without HAS_SETREUID. (Maybe those
	 * operating systems do not have such mount options anyway...)
	 * Seems safe enough to do as root.
	 */
#if !defined(NO_NOSUID_CHECK)
	if (fd_on_nosuid_fs(PerlIO_fileno(PL_rsfp))) {
	    Perl_croak(aTHX_ "Setuid script on nosuid or noexec filesystem\n");
	}
#endif
#endif /* IAMSUID */

	if (!S_ISREG(PL_statbuf.st_mode)) {
	    Perl_croak(aTHX_ "Setuid script not plain file\n");
	}
	if (PL_statbuf.st_mode & S_IWOTH)
	    Perl_croak(aTHX_ "Setuid/gid script is writable by world");
	PL_doswitches = FALSE;		/* -s is insecure in suid */
	/* PSz 13 Nov 03  But -s was caught elsewhere ... so unsetting it here is useless(?!) */
	CopLINE_inc(PL_curcop);
	if (sv_gets(PL_linestr, PL_rsfp, 0) == Nullch ||
	  strnNE(SvPV(PL_linestr,n_a),"#!",2) )	/* required even on Sys V */
	    Perl_croak(aTHX_ "No #! line");
	s = SvPV(PL_linestr,n_a)+2;
	/* PSz 27 Feb 04 */
	/* Sanity check on line length */
	if (strlen(s) < 1 || strlen(s) > 4000)
	    Perl_croak(aTHX_ "Very long #! line");
	/* Allow more than a single space after #! */
	while (isSPACE(*s)) s++;
	/* Sanity check on buffer end */
	while ((*s) && !isSPACE(*s)) s++;
	for (s2 = s;  (s2 > SvPV(PL_linestr,n_a)+2 &&
		       (isDIGIT(s2[-1]) || strchr("._-", s2[-1])));  s2--) ;
	/* Sanity check on buffer start */
	if ( (s2-4 < SvPV(PL_linestr,n_a)+2 || strnNE(s2-4,"perl",4)) &&
	      (s-9 < SvPV(PL_linestr,n_a)+2 || strnNE(s-9,"perl",4)) )
	    Perl_croak(aTHX_ "Not a perl script");
	while (*s == ' ' || *s == '\t') s++;
	/*
	 * #! arg must be what we saw above.  They can invoke it by
	 * mentioning suidperl explicitly, but they may not add any strange
	 * arguments beyond what #! says if they do invoke suidperl that way.
	 */
	/*
	 * The way validarg was set up, we rely on the kernel to start
	 * scripts with argv[1] set to contain all #! line switches (the
	 * whole line).
	 */
	/*
	 * Check that we got all the arguments listed in the #! line (not
	 * just that there are no extraneous arguments). Might not matter
	 * much, as switches from #! line seem to be acted upon (also), and
	 * so may be checked and trapped in perl. But, security checks must
	 * be done in suidperl and not deferred to perl. Note that suidperl
	 * does not get around to parsing (and checking) the switches on
	 * the #! line (but execs perl sooner).
	 * Allow (require) a trailing newline (which may be of two
	 * characters on some architectures?) (but no other trailing
	 * whitespace).
	 */
	len = strlen(validarg);
	if (strEQ(validarg," PHOOEY ") ||
	    strnNE(s,validarg,len) || !isSPACE(s[len]) ||
	    !(strlen(s) == len+1 || (strlen(s) == len+2 && isSPACE(s[len+1]))))
	    Perl_croak(aTHX_ "Args must match #! line");

#ifndef IAMSUID
	if (PL_fdscript < 0 &&
	    PL_euid != PL_uid && (PL_statbuf.st_mode & S_ISUID) &&
	    PL_euid == PL_statbuf.st_uid)
	    if (!PL_do_undump)
		Perl_croak(aTHX_ "YOU HAVEN'T DISABLED SET-ID SCRIPTS IN THE KERNEL YET!\n\
FIX YOUR KERNEL, OR PUT A C WRAPPER AROUND THIS SCRIPT!\n");
#endif /* IAMSUID */

	if (PL_fdscript < 0 &&
	    PL_euid) {	/* oops, we're not the setuid root perl */
	    /* PSz 18 Feb 04
	     * When root runs a setuid script, we do not go through the same
	     * steps of execing sperl and then perl with fd scripts, but
	     * simply set up UIDs within the same perl invocation; so do
	     * not have the same checks (on options, whatever) that we have
	     * for plain users. No problem really: would have to be a script
	     * that does not actually work for plain users; and if root is
	     * foolish and can be persuaded to run such an unsafe script, he
	     * might run also non-setuid ones, and deserves what he gets.
	     * 
	     * Or, we might drop the PL_euid check above (and rely just on
	     * PL_fdscript to avoid loops), and do the execs
	     * even for root.
	     */
#ifndef IAMSUID
	    int which;
	    /* PSz 11 Nov 03
	     * Pass fd script to suidperl.
	     * Exec suidperl, substituting fd script for scriptname.
	     * Pass script name as "subdir" of fd, which perl will grok;
	     * in fact will use that to distinguish this from "normal"
	     * usage, see comments above.
	     */
	    PerlIO_rewind(PL_rsfp);
	    PerlLIO_lseek(PerlIO_fileno(PL_rsfp),(Off_t)0,0);  /* just in case rewind didn't */
	    /* PSz 27 Feb 04  Sanity checks on scriptname */
	    if ((!scriptname) || (!*scriptname) ) {
		Perl_croak(aTHX_ "No setuid script name\n");
	    }
	    if (*scriptname == '-') {
		Perl_croak(aTHX_ "Setuid script name may not begin with dash\n");
		/* Or we might confuse it with an option when replacing
		 * name in argument list, below (though we do pointer, not
		 * string, comparisons).
		 */
	    }
	    for (which = 1; PL_origargv[which] && PL_origargv[which] != scriptname; which++) ;
	    if (!PL_origargv[which]) {
		Perl_croak(aTHX_ "Can't change argv to have fd script\n");
	    }
	    PL_origargv[which] = savepv(Perl_form(aTHX_ "/dev/fd/%d/%s",
					  PerlIO_fileno(PL_rsfp), PL_origargv[which]));
#if defined(HAS_FCNTL) && defined(F_SETFD)
	    fcntl(PerlIO_fileno(PL_rsfp),F_SETFD,0);	/* ensure no close-on-exec */
#endif
	    PERL_FPU_PRE_EXEC
	    PerlProc_execv(Perl_form(aTHX_ "%s/sperl"PERL_FS_VER_FMT, BIN_EXP,
				     (int)PERL_REVISION, (int)PERL_VERSION,
				     (int)PERL_SUBVERSION), PL_origargv);
	    PERL_FPU_POST_EXEC
#endif /* IAMSUID */
	    Perl_croak(aTHX_ "Can't do setuid (cannot exec sperl)\n");
	}

	if (PL_statbuf.st_mode & S_ISGID && PL_statbuf.st_gid != PL_egid) {
/* PSz 26 Feb 04
 * This seems back to front: we try HAS_SETEGID first; if not available
 * then try HAS_SETREGID; as a last chance we try HAS_SETRESGID. May be OK
 * in the sense that we only want to set EGID; but are there any machines
 * with either of the latter, but not the former? Same with UID, later.
 */
#ifdef HAS_SETEGID
	    (void)setegid(PL_statbuf.st_gid);
#else
#ifdef HAS_SETREGID
           (void)setregid((Gid_t)-1,PL_statbuf.st_gid);
#else
#ifdef HAS_SETRESGID
           (void)setresgid((Gid_t)-1,PL_statbuf.st_gid,(Gid_t)-1);
#else
	    PerlProc_setgid(PL_statbuf.st_gid);
#endif
#endif
#endif
	    if (PerlProc_getegid() != PL_statbuf.st_gid)
		Perl_croak(aTHX_ "Can't do setegid!\n");
	}
	if (PL_statbuf.st_mode & S_ISUID) {
	    if (PL_statbuf.st_uid != PL_euid)
#ifdef HAS_SETEUID
		(void)seteuid(PL_statbuf.st_uid);	/* all that for this */
#else
#ifdef HAS_SETREUID