Bug 20564

Summary: read builtin corrupts parameter assignment in loop
Product: [Retired] Red Hat Linux Reporter: b.g.m.kusters
Component: bashAssignee: Bernhard Rosenkraenzer <bero>
Status: CLOSED DUPLICATE QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: 6.2CC: dr
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Hardware: i386   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2000-11-10 09:42:20 UTC Type: ---
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Description b.g.m.kusters 2000-11-09 09:05:52 UTC
Tested in bash and bash2

Parameter assignment in loop is not exported out of the loop if read is used see script.
Same error occures if read is used in combinatie with pipe eg. 
tail -n 1 x2 | read p1 p2.
No assignment to parameters read take place.


#!/bin/bash2
echo "1" > x2
echo "2" >> x2
echo "Error parameter not exported"
d=""
cat x2|while read p1
do
 echo "d1 = $d"
 d="${d}${p1}"
 echo "d2 = $d"
done
echo "d3 = $d"

echo ""
echo "No Error parameter is exported"
d=""
set $(cat x2)
while [ $# -ne 0 ]
do
 p1=$1
 shift 1
 echo "d1 = $d"
 d="${d}${p1}"
 echo "d2 = $d"
done
echo "d3 = $d"

Comment 1 b.g.m.kusters 2000-11-09 09:10:42 UTC
TESTED with RedHat 6.2 not 4.2

Comment 2 Bernhard Rosenkraenzer 2000-11-10 09:46:27 UTC
This is another effect of the modifications to make bash compliant to the Single UNIX Specification (See bug #19747).


*** This bug has been marked as a duplicate of 19747 ***