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Diffstat (limited to '')
| -rw-r--r-- | builtins/psize.sh | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/builtins/psize.sh b/builtins/psize.sh new file mode 100644 index 0000000..29bc115 --- /dev/null +++ b/builtins/psize.sh @@ -0,0 +1,45 @@ +#! /bin/sh +# +# psize.sh -- determine this system's pipe size, and write a define to +# pipesize.h so ulimit.c can use it. + +: ${TMPDIR:=/tmp} +# try to use mktemp(1) if the system supports it +{ TMPFILE="`mktemp $TMPDIR/pipsize.XXXXXX 2>/dev/null`"; } 2>/dev/null +used_mktemp=true + +if [ -z "$TMPFILE" ]; then + TMPNAME=pipsize.$$ + TMPFILE=$TMPDIR/$TMPNAME + used_mktemp=false +fi + +trap 'rm -f "$TMPFILE" ; exit 1' 1 2 3 6 15 +trap 'rm -f "$TMPFILE"' 0 + +echo "/*" +echo " * pipesize.h" +echo " *" +echo " * This file is automatically generated by psize.sh" +echo " * Do not edit!" +echo " */" +echo "" + +# +# Try to avoid tempfile races. We can't really check for the file's +# existence before we run psize.aux, because `test -e' is not portable, +# `test -h' (test for symlinks) is not portable, and `test -f' only +# checks for regular files. If we used mktemp(1), we're ahead of the +# game. +# +$used_mktemp || rm -f "$TMPFILE" + +./psize.aux 2>"$TMPFILE" | sleep 3 + +if [ -s "$TMPFILE" ]; then + echo "#define PIPESIZE `cat "$TMPFILE"`" +else + echo "#define PIPESIZE 512" +fi + +exit 0 |