[metaconfig.git] / U / perl / fflushall.U

?RCS: $Id$
?RCS:
?RCS: Copyright (c) 1999, Jarkko Hietaniemi
?RCS:
?RCS: You may redistribute only under the terms of the Artistic License,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic License; a copy of which may be found at the root
?RCS: of the source tree for dist 3.0.
?RCS:
?MAKE:fflushNULL fflushall: Compile cat rm rm_try test osname run to from \
	Oldconfig Myread Setvar echo targethost \
	d_sysconf i_unistd d_stdio_stream_array stdio_stream_array i_stdlib
?MAKE:	-pick add $@ %<
?S:fflushNULL:
?S:	This symbol, if defined, tells that fflush(NULL) correctly
?S:	flushes all pending stdio output without side effects. In
?S:	particular, on some platforms calling fflush(NULL) *still*
?S:	corrupts STDIN if it is a pipe.
?S:.
?S:fflushall:
?S:	This symbol, if defined, tells that to flush
?S:	all pending stdio output one must loop through all
?S:	the stdio file handles stored in an array and fflush them.
?S:	Note that if fflushNULL is defined, fflushall will not
?S:	even be probed for and will be left undefined.
?S:.
?C:FFLUSH_NULL:
?C:	This symbol, if defined, tells that fflush(NULL) correctly
?C:	flushes all pending stdio output without side effects. In
?C:	particular, on some platforms calling fflush(NULL) *still*
?C:	corrupts STDIN if it is a pipe.
?C:.
?C:FFLUSH_ALL:
?C:	This symbol, if defined, tells that to flush
?C:	all pending stdio output one must loop through all
?C:	the stdio file handles stored in an array and fflush them.
?C:	Note that if fflushNULL is defined, fflushall will not
?C:	even be probed for and will be left undefined.
?C:.
?H:#$fflushNULL	FFLUSH_NULL 		/**/
?H:#$fflushall	FFLUSH_ALL 		/**/
?H:.
?T:output code
?F:!try.out !try !tryp
: Check how to flush
echo " "
$cat >&4 <<EOM
Checking how to flush all pending stdio output...
EOM
# I only know how to find the first 32 possibly open files on SunOS.
# See also hints/sunos_4_1.sh and util.c  --AD
case "$osname" in
sunos) $echo '#define PERL_FFLUSH_ALL_FOPEN_MAX 32' > try.c ;;
esac
$cat >>try.c <<EOCP
#include <stdio.h>
#$i_stdlib I_STDLIB
#ifdef I_STDLIB
#include <stdlib.h>
#endif
#$i_unistd I_UNISTD
#ifdef I_UNISTD
# include <unistd.h>
#endif
#$d_sysconf HAS_SYSCONF
#$d_stdio_stream_array HAS_STDIO_STREAM_ARRAY
#ifdef HAS_STDIO_STREAM_ARRAY
# define STDIO_STREAM_ARRAY $stdio_stream_array
#endif
int main() {
  FILE* p;
  unlink("try.out");
  p = fopen("try.out", "w");
#ifdef TRY_FPUTC
  fputc('x', p);
#else
# ifdef TRY_FPRINTF
  fprintf(p, "x");
# endif
#endif
#ifdef TRY_FFLUSH_NULL
  fflush(NULL);
#endif
#ifdef TRY_FFLUSH_ALL
  {
    long open_max = -1;
# ifdef PERL_FFLUSH_ALL_FOPEN_MAX
    open_max = PERL_FFLUSH_ALL_FOPEN_MAX;
# else
#  if defined(HAS_SYSCONF) && defined(_SC_OPEN_MAX)
    open_max = sysconf(_SC_OPEN_MAX);
#  else
#   ifdef FOPEN_MAX
    open_max = FOPEN_MAX;
#   else
#    ifdef OPEN_MAX
    open_max = OPEN_MAX;
#    else
#     ifdef _NFILE
    open_max = _NFILE;
#     endif
#    endif
#   endif
#  endif
# endif
# ifdef HAS_STDIO_STREAM_ARRAY
    if (open_max > 0) {
      long i;
      for (i = 0; i < open_max; i++)
	    if (STDIO_STREAM_ARRAY[i]._file >= 0 &&
		STDIO_STREAM_ARRAY[i]._file < open_max &&
		STDIO_STREAM_ARRAY[i]._flag)
		fflush(&STDIO_STREAM_ARRAY[i]);
    }
  }
# endif
#endif
  _exit(42);
}
EOCP
: first we have to find out how _not_ to flush
$to try.c
if $test "X$fflushNULL" = X -o "X$fflushall" = X; then
    output=''
    set try -DTRY_FPUTC
    if eval $compile; then
	    $run ./try 2>/dev/null
	    code="$?"
	    $from try.out
	    if $test ! -s try.out -a "X$code" = X42; then
		output=-DTRY_FPUTC
	    fi
    fi
    case "$output" in
    '')
	    set try -DTRY_FPRINTF
	    if eval $compile; then
		    $run ./try 2>/dev/null
		    code="$?"
		    $from try.out
		    if $test ! -s try.out -a "X$code" = X42; then
			output=-DTRY_FPRINTF
		    fi
	    fi
	;;
    esac
fi
: check for fflush NULL behavior
case "$fflushNULL" in
'') 	set try -DTRY_FFLUSH_NULL $output
	if eval $compile; then
		$run ./try 2>/dev/null
		code="$?"
		$from try.out
		if $test -s try.out -a "X$code" = X42; then
			fflushNULL="`$cat try.out`"
		else
			if $test "X$code" != X42; then
				$cat >&4 <<EOM
(If this test failed, don't worry, we'll try another method shortly.)
EOM
			fi
		fi
	fi
	$rm -f core try.core core.try.*
	case "$fflushNULL" in
	x)	$cat >&4 <<EOM
Your fflush(NULL) works okay for output streams.
Let's see if it clobbers input pipes...
EOM
# As of mid-March 2000 all versions of Solaris appear to have a stdio
# bug that improperly flushes the input end of pipes.  So we avoid the
# autoflush on fork/system/exec support for now. :-(
$cat >tryp.c <<EOCP
#include <stdio.h>
int
main(int argc, char **argv)
{
    char buf[1024];
    int i;
    char *bp = buf;
    while (1) {
	while ((i = getc(stdin)) != -1
	       && (*bp++ = i) != '\n'
	       && bp < &buf[1024])
	/* DO NOTHING */ ;
	*bp = '\0';
	fprintf(stdout, "%s", buf);
	fflush(NULL);
	if (i == -1)
	    return 0;
	bp = buf;
    }
}
EOCP
		fflushNULL="$define"
		set tryp
		if eval $compile; then
		    $rm -f tryp.out
		    # Copy the .c file to the remote host ($to is an ssh-alike if targethost is set)
		    if $test "X$targethost" != X; then
			$to tryp.c
			$to tryp
			$run "cat tryp.c | ./tryp " 2>/dev/null > tryp.out
		    else
			$cat tryp.c | $run ./tryp   2>/dev/null > tryp.out
		    fi
		    if cmp tryp.c tryp.out >/dev/null 2>&1; then
		       $cat >&4 <<EOM
fflush(NULL) seems to behave okay with input streams.
EOM
			fflushNULL="$define"
		    else
			$cat >&4 <<EOM
Ouch, fflush(NULL) clobbers input pipes!  We will not use it.
EOM
			fflushNULL="$undef"
		    fi
		fi
		$rm -f core tryp.c tryp.core core.tryp.*
		;;
	'')	$cat >&4 <<EOM
Your fflush(NULL) isn't working (contrary to ANSI C).
EOM
		fflushNULL="$undef"
		;;
	*)	$cat >&4 <<EOM
Cannot figure out whether your fflush(NULL) works or not.
I'm assuming it doesn't (contrary to ANSI C).
EOM
		fflushNULL="$undef"
		;;
	esac
	;;
$define|true|[yY]*)
	fflushNULL="$define"
	;;
*)
	fflushNULL="$undef"
	;;
esac
: check explicit looping only if NULL did not work, and if the pipe
: bug does not show up on an explicit flush too
case "$fflushNULL" in
"$undef")
	$cat >tryp.c <<EOCP
#include <stdio.h>
int
main(int argc, char **argv)
{
    char buf[1024];
    int i;
    char *bp = buf;
    while (1) {
	while ((i = getc(stdin)) != -1
	       && (*bp++ = i) != '\n'
	       && bp < &buf[1024])
	/* DO NOTHING */ ;
	*bp = '\0';
	fprintf(stdout, "%s", buf);
	fflush(stdin);
	if (i == -1)
	    return 0;
	bp = buf;
    }
}
EOCP
	set tryp
	if eval $compile; then
	    $rm -f tryp.out
	    if $test "X$targethost" != X; then
		$to tryp.c
		$to tryp
		$run "cat tryp.c | ./tryp " 2>/dev/null > tryp.out
	    else
		$cat tryp.c | $run ./tryp   2>/dev/null > tryp.out
	    fi
	    if cmp tryp.c tryp.out >/dev/null 2>&1; then
	       $cat >&4 <<EOM
Good, at least fflush(stdin) seems to behave okay when stdin is a pipe.
EOM
		: now check for fflushall behaviour
		case "$fflushall" in
		'') 	set try -DTRY_FFLUSH_ALL $output
			if eval $compile; then
				$cat >&4 <<EOM
(Now testing the other method--but note that this also may fail.)
EOM
				$run ./try 2>/dev/null
				code=$?
				$from try.out
				if $test -s try.out -a "X$code" = X42; then
					fflushall="`$cat try.out`"
				fi
			fi
			$rm_try
			case "$fflushall" in
			x)	$cat >&4 <<EOM
Whew. Flushing explicitly all the stdio streams works.
EOM
				fflushall="$define"
				;;
			'')	$cat >&4 <<EOM
Sigh. Flushing explicitly all the stdio streams doesn't work.
EOM
				fflushall="$undef"
				;;
			*)	$cat >&4 <<EOM
Cannot figure out whether flushing stdio streams explicitly works or not.
I'm assuming it doesn't.
EOM
				fflushall="$undef"
				;;
			esac
			;;
		"$define"|true|[yY]*)
			fflushall="$define"
			;;
		*)
			fflushall="$undef"
			;;
		esac
	    else
		$cat >&4 <<EOM
All is futile.  Even fflush(stdin) clobbers input pipes!
EOM
		fflushall="$undef"
	    fi
	else
	    fflushall="$undef"
	fi
	$rm -f core tryp.c tryp.core core.tryp.*
	;;
*)	fflushall="$undef"
	;;
esac

case "$fflushNULL$fflushall" in
undefundef)
	$cat <<EOM
OK, I give up.  I cannot figure out how to flush pending stdio output.
We won't be flushing handles at all before fork/exec/popen.
EOM
	;;
esac
$rm_try tryp
Commit	Line	Data
959f3c4c JH	1	?RCS: $Id$
	2	?RCS:
	3	?RCS: Copyright (c) 1999, Jarkko Hietaniemi
0065f4af	4	?RCS:
65a32477	5	?RCS: You may redistribute only under the terms of the Artistic License,
959f3c4c JH	6	?RCS: as specified in the README file that comes with the distribution.
959f3c4c JH	7	?RCS: You may reuse parts of this distribution only within the terms of
65a32477	8	?RCS: that same Artistic License; a copy of which may be found at the root
959f3c4c JH	9	?RCS: of the source tree for dist 3.0.
959f3c4c JH	10	?RCS:
2cb64bf6	11	?MAKE:fflushNULL fflushall: Compile cat rm rm_try test osname run to from \
9c11722e	12	Oldconfig Myread Setvar echo targethost \
1273bb5e	13	d_sysconf i_unistd d_stdio_stream_array stdio_stream_array i_stdlib
959f3c4c JH	14	?MAKE: -pick add $@ %<
959f3c4c JH	15	?S:fflushNULL:
1c13d0ab MBT	16	?S: This symbol, if defined, tells that fflush(NULL) correctly
	17	?S: flushes all pending stdio output without side effects. In
	18	?S: particular, on some platforms calling fflush(NULL) still
	19	?S: corrupts STDIN if it is a pipe.
959f3c4c JH	20	?S:.
	21	?S:fflushall:
	22	?S: This symbol, if defined, tells that to flush
	23	?S: all pending stdio output one must loop through all
	24	?S: the stdio file handles stored in an array and fflush them.
	25	?S: Note that if fflushNULL is defined, fflushall will not
	26	?S: even be probed for and will be left undefined.
	27	?S:.
	28	?C:FFLUSH_NULL:
1c13d0ab MBT	29	?C: This symbol, if defined, tells that fflush(NULL) correctly
	30	?C: flushes all pending stdio output without side effects. In
	31	?C: particular, on some platforms calling fflush(NULL) still
	32	?C: corrupts STDIN if it is a pipe.
959f3c4c JH	33	?C:.
	34	?C:FFLUSH_ALL:
	35	?C: This symbol, if defined, tells that to flush
	36	?C: all pending stdio output one must loop through all
	37	?C: the stdio file handles stored in an array and fflush them.
	38	?C: Note that if fflushNULL is defined, fflushall will not
	39	?C: even be probed for and will be left undefined.
	40	?C:.
	41	?H:#$fflushNULL FFLUSH_NULL /**/
	42	?H:#$fflushall FFLUSH_ALL /**/
	43	?H:.
	44	?T:output code
41322e17	45	?F:!try.out !try !tryp
0065f4af	46	: Check how to flush
959f3c4c JH	47	echo " "
	48	$cat >&4 <<EOM
	49	Checking how to flush all pending stdio output...
	50	EOM
	51	# I only know how to find the first 32 possibly open files on SunOS.
	52	# See also hints/sunos_4_1.sh and util.c --AD
	53	case "$osname" in
	54	sunos) $echo '#define PERL_FFLUSH_ALL_FOPEN_MAX 32' > try.c ;;
	55	esac
	56	$cat >>try.c <<EOCP
	57	#include <stdio.h>
1273bb5e JH	58	#$i_stdlib I_STDLIB
	59	#ifdef I_STDLIB
	60	#include <stdlib.h>
	61	#endif
959f3c4c JH	62	#$i_unistd I_UNISTD
	63	#ifdef I_UNISTD
	64	# include <unistd.h>
	65	#endif
	66	#$d_sysconf HAS_SYSCONF
	67	#$d_stdio_stream_array HAS_STDIO_STREAM_ARRAY
	68	#ifdef HAS_STDIO_STREAM_ARRAY
	69	# define STDIO_STREAM_ARRAY $stdio_stream_array
	70	#endif
	71	int main() {
0f00356b JH	72	FILE* p;
	73	unlink("try.out");
	74	p = fopen("try.out", "w");
959f3c4c JH	75	#ifdef TRY_FPUTC
	76	fputc('x', p);
	77	#else
	78	# ifdef TRY_FPRINTF
	79	fprintf(p, "x");
	80	# endif
	81	#endif
	82	#ifdef TRY_FFLUSH_NULL
	83	fflush(NULL);
	84	#endif
	85	#ifdef TRY_FFLUSH_ALL
	86	{
	87	long open_max = -1;
	88	# ifdef PERL_FFLUSH_ALL_FOPEN_MAX
	89	open_max = PERL_FFLUSH_ALL_FOPEN_MAX;
	90	# else
	91	# if defined(HAS_SYSCONF) && defined(_SC_OPEN_MAX)
	92	open_max = sysconf(_SC_OPEN_MAX);
	93	# else
	94	# ifdef FOPEN_MAX
	95	open_max = FOPEN_MAX;
	96	# else
	97	# ifdef OPEN_MAX
	98	open_max = OPEN_MAX;
	99	# else
	100	# ifdef _NFILE
	101	open_max = _NFILE;
	102	# endif
	103	# endif
	104	# endif
	105	# endif
2cb64bf6	106	# endif
959f3c4c JH	107	# ifdef HAS_STDIO_STREAM_ARRAY
	108	if (open_max > 0) {
	109	long i;
	110	for (i = 0; i < open_max; i++)
	111	if (STDIO_STREAM_ARRAY[i]._file >= 0 &&
	112	STDIO_STREAM_ARRAY[i]._file < open_max &&
	113	STDIO_STREAM_ARRAY[i]._flag)
	114	fflush(&STDIO_STREAM_ARRAY[i]);
2cb64bf6	115	}
959f3c4c JH	116	}
	117	# endif
	118	#endif
	119	_exit(42);
	120	}
	121	EOCP
	122	: first we have to find out how _not_ to flush
0f00356b	123	$to try.c
959f3c4c JH	124	if $test "X$fflushNULL" = X -o "X$fflushall" = X; then
	125	output=''
	126	set try -DTRY_FPUTC
	127	if eval $compile; then
9c11722e	128	$run ./try 2>/dev/null
f5a7caaa	129	code="$?"
0f00356b	130	$from try.out
f5a7caaa	131	if $test ! -s try.out -a "X$code" = X42; then
959f3c4c JH	132	output=-DTRY_FPUTC
	133	fi
	134	fi
	135	case "$output" in
	136	'')
	137	set try -DTRY_FPRINTF
959f3c4c	138	if eval $compile; then
9c11722e	139	$run ./try 2>/dev/null
f5a7caaa	140	code="$?"
0f00356b	141	$from try.out
f5a7caaa	142	if $test ! -s try.out -a "X$code" = X42; then
959f3c4c JH	143	output=-DTRY_FPRINTF
	144	fi
	145	fi
	146	;;
	147	esac
	148	fi
65a32477	149	: check for fflush NULL behavior
959f3c4c JH	150	case "$fflushNULL" in
	151	'') set try -DTRY_FFLUSH_NULL $output
	152	if eval $compile; then
9c11722e	153	$run ./try 2>/dev/null
959f3c4c	154	code="$?"
0f00356b	155	$from try.out
959f3c4c JH	156	if $test -s try.out -a "X$code" = X42; then
	157	fflushNULL="`$cat try.out`"
	158	else
	159	if $test "X$code" != X42; then
	160	$cat >&4 <<EOM
	161	(If this test failed, don't worry, we'll try another method shortly.)
	162	EOM
	163	fi
	164	fi
	165	fi
a45723d1	166	$rm -f core try.core core.try.*
959f3c4c JH	167	case "$fflushNULL" in
959f3c4c JH	168	x) $cat >&4 <<EOM
5ef94ee9 JH	169	Your fflush(NULL) works okay for output streams.
5ef94ee9 JH	170	Let's see if it clobbers input pipes...
959f3c4c	171	EOM
5ef94ee9 JH	172	# As of mid-March 2000 all versions of Solaris appear to have a stdio
	173	# bug that improperly flushes the input end of pipes. So we avoid the
	174	# autoflush on fork/system/exec support for now. :-(
	175	$cat >tryp.c <<EOCP
	176	#include <stdio.h>
	177	int
	178	main(int argc, char **argv)
	179	{
	180	char buf[1024];
	181	int i;
	182	char *bp = buf;
	183	while (1) {
9c11722e MB	184	while ((i = getc(stdin)) != -1
	185	&& (*bp++ = i) != '\n'
	186	&& bp < &buf[1024])
	187	/* DO NOTHING */ ;
	188	*bp = '\0';
	189	fprintf(stdout, "%s", buf);
	190	fflush(NULL);
	191	if (i == -1)
1b13c38f	192	return 0;
9c11722e	193	bp = buf;
5ef94ee9 JH	194	}
	195	}
	196	EOCP
9c11722e MB	197	fflushNULL="$define"
	198	set tryp
	199	if eval $compile; then
	200	$rm -f tryp.out
	201	# Copy the .c file to the remote host ($to is an ssh-alike if targethost is set)
	202	if $test "X$targethost" != X; then
	203	$to tryp.c
76d1bd01	204	$to tryp
5f6c99a5	205	$run "cat tryp.c \| ./tryp " 2>/dev/null > tryp.out
9c11722e	206	else
5f6c99a5	207	$cat tryp.c \| $run ./tryp 2>/dev/null > tryp.out
9c11722e MB	208	fi
	209	if cmp tryp.c tryp.out >/dev/null 2>&1; then
	210	$cat >&4 <<EOM
5ef94ee9 JH	211	fflush(NULL) seems to behave okay with input streams.
	212	EOM
	213	fflushNULL="$define"
9c11722e	214	else
5ef94ee9 JH	215	$cat >&4 <<EOM
	216	Ouch, fflush(NULL) clobbers input pipes! We will not use it.
	217	EOM
9c11722e MB	218	fflushNULL="$undef"
	219	fi
	220	fi
	221	$rm -f core tryp.c tryp.core core.tryp.*
959f3c4c JH	222	;;
	223	'') $cat >&4 <<EOM
	224	Your fflush(NULL) isn't working (contrary to ANSI C).
	225	EOM
	226	fflushNULL="$undef"
	227	;;
	228	*) $cat >&4 <<EOM
	229	Cannot figure out whether your fflush(NULL) works or not.
	230	I'm assuming it doesn't (contrary to ANSI C).
	231	EOM
	232	fflushNULL="$undef"
	233	;;
	234	esac
	235	;;
	236	$define\|true\|[yY]*)
	237	fflushNULL="$define"
	238	;;
	239	*)
	240	fflushNULL="$undef"
	241	;;
	242	esac
1b13c38f JH	243	: check explicit looping only if NULL did not work, and if the pipe
1b13c38f JH	244	: bug does not show up on an explicit flush too
959f3c4c JH	245	case "$fflushNULL" in
959f3c4c JH	246	"$undef")
1b13c38f JH	247	$cat >tryp.c <<EOCP
	248	#include <stdio.h>
	249	int
	250	main(int argc, char **argv)
	251	{
	252	char buf[1024];
	253	int i;
	254	char *bp = buf;
	255	while (1) {
	256	while ((i = getc(stdin)) != -1
	257	&& (*bp++ = i) != '\n'
	258	&& bp < &buf[1024])
	259	/* DO NOTHING */ ;
	260	*bp = '\0';
	261	fprintf(stdout, "%s", buf);
	262	fflush(stdin);
	263	if (i == -1)
	264	return 0;
	265	bp = buf;
	266	}
	267	}
	268	EOCP
	269	set tryp
	270	if eval $compile; then
	271	$rm -f tryp.out
9c11722e MB	272	if $test "X$targethost" != X; then
9c11722e MB	273	$to tryp.c
76d1bd01	274	$to tryp
5f6c99a5	275	$run "cat tryp.c \| ./tryp " 2>/dev/null > tryp.out
9c11722e	276	else
5f6c99a5	277	$cat tryp.c \| $run ./tryp 2>/dev/null > tryp.out
9c11722e	278	fi
1b13c38f JH	279	if cmp tryp.c tryp.out >/dev/null 2>&1; then
	280	$cat >&4 <<EOM
	281	Good, at least fflush(stdin) seems to behave okay when stdin is a pipe.
959f3c4c	282	EOM
1b13c38f	283	: now check for fflushall behaviour
959f3c4c	284	case "$fflushall" in
1b13c38f JH	285	'') set try -DTRY_FFLUSH_ALL $output
	286	if eval $compile; then
	287	$cat >&4 <<EOM
	288	(Now testing the other method--but note that this also may fail.)
	289	EOM
0f00356b	290	$run ./try 2>/dev/null
f5a7caaa JH	291	code=$?
	292	$from try.out
	293	if $test -s try.out -a "X$code" = X42; then
1b13c38f JH	294	fflushall="`$cat try.out`"
	295	fi
	296	fi
2cb64bf6	297	$rm_try
1b13c38f JH	298	case "$fflushall" in
1b13c38f JH	299	x) $cat >&4 <<EOM
959f3c4c JH	300	Whew. Flushing explicitly all the stdio streams works.
959f3c4c JH	301	EOM
1b13c38f JH	302	fflushall="$define"
	303	;;
	304	'') $cat >&4 <<EOM
959f3c4c JH	305	Sigh. Flushing explicitly all the stdio streams doesn't work.
959f3c4c JH	306	EOM
1b13c38f JH	307	fflushall="$undef"
	308	;;
	309	*) $cat >&4 <<EOM
959f3c4c JH	310	Cannot figure out whether flushing stdio streams explicitly works or not.
	311	I'm assuming it doesn't.
	312	EOM
1b13c38f JH	313	fflushall="$undef"
	314	;;
	315	esac
	316	;;
	317	"$define"\|true\|[yY]*)
	318	fflushall="$define"
	319	;;
	320	*)
959f3c4c JH	321	fflushall="$undef"
	322	;;
	323	esac
1b13c38f JH	324	else
	325	$cat >&4 <<EOM
	326	All is futile. Even fflush(stdin) clobbers input pipes!
	327	EOM
959f3c4c	328	fflushall="$undef"
1b13c38f JH	329	fi
	330	else
	331	fflushall="$undef"
	332	fi
	333	$rm -f core tryp.c tryp.core core.tryp.*
959f3c4c	334	;;
1b13c38f	335	*) fflushall="$undef"
959f3c4c JH	336	;;
959f3c4c JH	337	esac
1b13c38f	338
959f3c4c JH	339	case "$fflushNULL$fflushall" in
	340	undefundef)
	341	$cat <<EOM
1b13c38f JH	342	OK, I give up. I cannot figure out how to flush pending stdio output.
1b13c38f JH	343	We won't be flushing handles at all before fork/exec/popen.
959f3c4c JH	344	EOM
	345	;;
	346	esac
41322e17	347	$rm_try tryp
959f3c4c	348