[Solved]Using global variables

bharani · 2009-08-22 08:44:36

I am writing a simple bash script to read a file line by line and add all the last words in the file.

tt=0
pline(){  
    shift $(($# - 1)) 
    tt=$(($tt+$1))    
        }
cat cc.list | while read line; do
pline $line
done 
echo $tt

The cc.list file is

pen 10
pencil 50
rubber 5

I want the echo to print 65 as the result. But it is always printing 0.
Please help me.

Last edited by bharani (2009-08-22 10:09:35)

majiq · 2009-08-22 09:05:59

I was beating myself over the head trying to figure this out...

tl;dr: You're doing it fine, but the pipe makes a subshell in which the tt that is used is destroyed by the time the loop is finished.

Edit:

I should've thought to suggest ways around this. Try

#!/bin/bash
tt=0
pline(){
    shift $(( $# - 1 )) 
    tt=$(($tt+$1))
        }
while read line; do
pline $line
done < cc.list
echo $tt

Last edited by majiq (2009-08-22 09:13:44)

bharani · 2009-08-22 10:09:07

Thank you.
I used this script after reading your post( before you edited it)

tt=0
pline(){  
    shift $(($# - 1)) 
    tt=$(($tt+$1))    
        }
 exec<$1
while read line
do
pline $line
done 
echo "Total is " $tt

Last edited by bharani (2009-08-22 10:10:34)

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