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scope of the variable - Naga

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Top Forums Shell Programming and Scripting scope of the variable - Naga
# 8  
Old 04-27-2009
nagnatar ,
I am not facing the problem when i execute it on my system.
If you are facing it then it be because of export .

But according to me export should not alter any results.
It justs exports the value to the child processes .
# 9  
Old 04-27-2009
nagnatar ,
I am not facing the problem when i execute it on my system.
If you are facing it then it be because of export .

But according to me export should not alter any results.
It justs exports the value to the child processes .
# 10  
Old 04-27-2009
try changing the shell use ksh/bash and then try ..

Code:
$ cat num
1
2
3
$ 

$ cat a.sh
i=0                         # Look i have not specified any shell here ..
while read j
do
    if [ ! -z "$j" ]        # CHECK IF LINE IS NOT ZERO ( EMPTY ) 
    then
        i=$(( $i + $j ))
    fi
done < num
echo "Total is : [$i]"
$

$ bash a.sh ; ksh a.sh
Total is : [6]
Total is : [6]
$

# 11  
Old 04-27-2009
Yes, Its working on ksh. but not on sh. any idea why its not working in sh?

Thanks!
# 12  
Old 04-27-2009
Pradeep and Zedex

Can you tell me which OS and which shell you are using?

I tested in linux, my script works well.

but found that my script does not give expected output in Sun OS 9 and 10 [sh]
however sun os gives correct output in ksh.. :-(

any idea? Thanks!
# 13  
Old 04-27-2009
for better understanding

# more add.sh
i=0
while read line
do
k=`expr $i + $line`
i=$k
done < num
echo "Final : ${i}"


# sh add.sh
Final : 0 -------------> Here is my question..why sh gives zero as output when bash, and ksh gives correct output

# ksh add.sh
Final : 20

# bash add.sh
Final : 20
# 14  
Old 04-27-2009
Hi.

As we have seen empirically in Solaris sh:
Quote:
If the input or the output of a while or until loop is
redirected, the commands in the loop are run in a sub-shell,
and variables set or changed there have no effect on the
parent process:

lastline=
while read line
do




SunOS 5.10 Last change: 2 May 2008 26






User Commands sh(1)



lastline=$line
done < /etc/passwd
echo "lastline=$lastline" # lastline is empty!

-- excerpt form man sh
I think most of the folks who answer questions here will focus on obtaining alternate solutions to problems, as opposed to digging to find why something does not work ... cheers, drl
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