# $Id: Head.U,v 3.0.1.9 1997/02/28 15:02:09 ram Exp $
#
-# Generated on Fri Mar 10 03:07:09 EET 2000 [metaconfig 3.0 PL70]
+# Generated on Sun Mar 12 19:42:40 EET 2000 [metaconfig 3.0 PL70]
# (with additional metaconfig patches by perlbug@perl.com)
cat >/tmp/c1$$ <<EOF
$rm -f core try.core core.try.*
case "$fflushNULL" in
x) $cat >&4 <<EOM
-Your fflush(NULL) works okay.
+Your fflush(NULL) works okay for output streams.
+Let's see if it clobbers input pipes...
EOM
- fflushNULL="$define"
+# 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
+ $cat tryp.c | ./tryp$exe_ext 2>/dev/null > tryp.out
+ 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.*
;;
'') $cat >&4 <<EOM
Your fflush(NULL) isn't working (contrary to ANSI C).
fflushNULL="$undef"
;;
esac
-: check explicit looping only if NULL did not work
+: 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")
- : check for fflush all 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 also this may fail.)
+ $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
+ $cat tryp.c | ./tryp$exe_ext 2>/dev/null > tryp.out
+ 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
- $rm -f try.out
- ./try$exe_ext 2>/dev/null
- if $test -s try.out -a "X$?" = X42; then
- fflushall="`$cat try.out`"
- fi
- fi
- $rm -f core try.core core.try.*
+ : now check for fflushall behaviour
case "$fflushall" in
- x) $cat >&4 <<EOM
+ '') 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
+ $rm -f try.out
+ ./try$exe_ext 2>/dev/null
+ if $test -s try.out -a "X$?" = X42; then
+ fflushall="`$cat try.out`"
+ fi
+ fi
+ $rm -f core try.core core.try.*
+ case "$fflushall" in
+ x) $cat >&4 <<EOM
Whew. Flushing explicitly all the stdio streams works.
EOM
- fflushall="$define"
- ;;
- '') $cat >&4 <<EOM
+ fflushall="$define"
+ ;;
+ '') $cat >&4 <<EOM
Sigh. Flushing explicitly all the stdio streams doesn't work.
EOM
- fflushall="$undef"
- ;;
- *) $cat >&4 <<EOM
+ fflushall="$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="$undef"
;;
esac
- ;;
- "$define"|true|[yY]*)
- fflushall="$define"
- ;;
- *)
+ else
+ $cat >&4 <<EOM
+All is futile. Even fflush(stdin) clobbers input pipes!
+EOM
fflushall="$undef"
- ;;
- esac
+ fi
+ else
+ fflushall="$undef"
+ fi
+ $rm -f core tryp.c tryp.core core.tryp.*
;;
-*) fflushall="$undef"
+*) fflushall="$undef"
;;
esac
+
case "$fflushNULL$fflushall" in
undefundef)
$cat <<EOM
-I cannot figure out how to flush pending stdio output.
+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
projects / p5sagit/p5-mst-13.2.git / blobdiff