while do done has problems with global variables

[Joern . Rink]

Configuration Information [Automatically generated, do not change]:
Machine: s390
OS: linux
Compiler: gcc -I/usr/src/packages/BUILD/bash-2.05b
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='s390'
-DCONF_OSTYPE='linux' -DCONF_MACHTYPE='s390-ibm-linux' -DCONF_VENDOR='ibm'
-DSHELL -DHAVE_CONFIG_H  -I.  -I. -I./include -I./lib  -O2 -fsigned-char
-D_GNU_SOURCE -Wall -pipe -g
uname output: Linux LXPTIV01 2.4.21-292-default #1 SMP Wed May 25 13:26:41
UTC 2005 s390 unknown
Machine Type: s390-ibm-linux

Bash Version: 2.05b
Patch Level: 0
Release Status: release

Description:
        [#!/bin/bash
I=5

function F_Muster
{
   ls -1  | while read f; do
      let I=I+1
      export I
      echo "I is $I"
   done
   echo "I after loop: $I"
   ((I=I+10))
   return 0
}

F_Muster
echo "========: $I"
exit 0


produces:
[xgadrin@mobile bash]$ ./bash_p.sh
I is 6
I after loop: 5
========: 15

That means, in the loop we can work with the global Variable I, but not
after the loop, I is reset to 5.

We have tested this on bash on fedora, aix linux-s390.
On ksh the script works as expected.

]

Repeat-By:
        [Describe the sequence of events that causes the problem
        to occur.]

Fix:
        [Description of how to fix the problem.  If you don't know a
        fix for the problem, don't include this section.]

Mit freundlichen Grüßen

Jörn Rink
Produktion / Basis und Infrastruktur
Tel.: 0251 7133 - 1410  -  Fax.:  0251 7133 - 91410
eMail:  Joern.Rink@gad.de

GAD eG
Weseler Straße 500 - 48163 Münster
http://www.gad.de