From: Alan Burlison <aburlison@cix.compulink.co.uk>
Date: Thu, 6 Mar 1997 03:28:00 +0000 (+1300)
Subject: Don't count on 'trap 0' inside () in shell script
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=2626e112ed2a75058c6a5e98cce21f1af08a8ace;p=p5sagit%2Fp5-mst-13.2.git

Don't count on 'trap 0' inside () in shell script

When building 5.003_91, I noticed that Configure leaves a load of files lying
around in /tmp, for example exp21743c, etc.  These appear to contain lists of
symbols.  A bit of digging reveals that the offender is the perl_exp.SH
script.  This contains a bit of code of the form

        (
        trap "rm -f ...." 0
        ...
        )

I guess that when the sub-shell invoked by the ( ... ) construct exits, the
trap 0 should be taken, and the files removed.  Unfortunately, I have noticed
that on at least 2 systems (UnixWare & Unisys SVR4) this doesn't happen.  The
following patch fixes it.

p5p-msgid: memo.147326@cix.compulink.co.uk
---

diff --git a/perl_exp.SH b/perl_exp.SH
index d964bdf..21165e0 100755
--- a/perl_exp.SH
+++ b/perl_exp.SH
@@ -40,11 +40,9 @@ echo "#!" > perl.exp
 
 case "$bincompat3" in
 y*)
-	(
 	  global=/tmp/exp$$g
 	  interp=/tmp/exp$$i
 	  compat3=/tmp/exp$$c
-	  trap 'rm -f $global $interp $compat3' 0
 	  trap 'exit 1' 1 2 3 13 15
 	  grep '^[A-Za-z]' global.sym | sort >$global
 	  grep '^[A-Za-z]' interp.sym | sort >$interp
@@ -53,7 +51,7 @@ y*)
 	  comm -12 $interp $compat3 | sed 's/^/Perl_/' >> perl.exp
 	  comm -12 $global $compat3 >> perl.exp
 	  comm -23 $interp $compat3 >> perl.exp
-	)
+	  rm -f $global $interp $compat3
 	;;
 *)
 	sed -n '/^[A-Za-z]/ s/^/Perl_/p' global.sym interp.sym >> perl.exp