[SOLVED] Break command in Linux

nishanthp82 · 04-25-2012, 02:21 PM

Hi

cat $DATAFILE | while read LINE
do
REC_ID=`echo $LINE | awk -F: '{print $1}'`
echo "rec_id value is:$REC_ID"
if [ $REC_ID = $1 ]
then
echo "iam in step1"
RUNCNTL=$REC_ID
echo "runcntl is $RUNCNTL"
break
fi
echo "runcntl is $RUNCNTL"

after the break command,the value for RUNCNTL gets lost!!
do you know why? or any other command can i use in place of break command,so value does not lost?

Thanks for reply

Kustom42 · 04-25-2012, 02:25 PM

With for and while loops the variables inside of the them are local to the loop only and are not global. You can export the variable and make it global. Do some searching on exporting variables.
Also please use the '[CODE]' tags for your code.

whizje · 04-25-2012, 02:29 PM

Add at the beginning of your script

Code:

RUNCNTL=""
export RUNCNTL

Kustom42 · 04-25-2012, 02:30 PM

You need to export the variable inside of the loop not before it.

whizje · 04-25-2012, 02:57 PM

Why?

Code:

#!/bin/bash
RUNCNTL=""
export RUNCNTL
for ((i=1; i<=100; i++))
do
 RUNCNTL=$i
 if (( i == 50 ))
 then 
   break
 fi
done 
echo $RUNCNTL

Code:

bash-4.1$ ./s.sh
50

nishanthp82 · 04-25-2012, 04:07 PM

Still not working

#!/bin/sh
RUNCNTL=""
export RUNCNTL
cat $DATAFILE | while read LINE
do
REC_ID=`echo $LINE | awk -F: '{print $1}'`
echo "rec_id value is:$REC_ID"
RUNCNTL=$REC_ID
#echo $RUNCNTL

if (( $REC_ID == $1 ))
#if [ $REC_ID = $1 ]
then
break
fi
done
echo $RUNCNTL
output:
./nishanth1.sh aa_distributed
rec_id value is:aa_distributed

Kustom42 · 04-25-2012, 04:26 PM

Try:

Code:

#!/bin/sh
RUNCNTL=""

cat $DATAFILE | while read LINE
do
REC_ID=`echo $LINE | awk -F: '{print $1}'`
echo "rec_id value is:$REC_ID"
RUNCNTL=$REC_ID
export RUNCNTL
#echo $RUNCNTL

if (( $REC_ID == $1 ))
#if [ $REC_ID = $1 ]
then
break
fi
done
echo $RUNCNTL

catkin · 04-25-2012, 08:49 PM

Quote:

Originally Posted by Kustom42

With for and while loops the variables inside of the them are local to the loop only and are not global

That is not correct:

Code:

c@CW8:/tmp$ foo=
c@CW8:/tmp$ for ((i=0; i<5; i++)); do foo=bar; break; done
c@CW8:/tmp$ echo $foo
bar

catkin · 04-25-2012, 08:57 PM

In pipelines the individual commands are run in subshells so any changes made to variables while executing the pipeline are not available to the calling shell:

Code:

c@CW8:/tmp$ foo=
echo 'a
b' | while read line; do echo $line; foo=bar; echo $foo; break; done
a
bar
c@CW8:/tmp$ echo $foo
[no output]

A workaround is to use input redirection into the loop:

Code:

c@CW8:/tmp$ foo=
c@CW8:/tmp$ while read line; do echo $line; foo=bar; echo $foo; break; done < input.txt 
a
bar
c@CW8:/tmp$ echo $foo
bar

nishanthp82 · 04-25-2012, 10:20 PM

still not working guys!

catkin · 04-25-2012, 10:47 PM

Then it would be helpful to see your latest script, the input file, the command you used to run the script and the output.

nishanthp82 · 04-25-2012, 11:11 PM

#!/bin/sh
RUNCNTL=""
export RUNCNTL
BASEDIR=/psoft/batch/fsdev
DATAFILE=$BASEDIR/scripts/alloc_runctl_groups.dat
cat $DATAFILE | while read LINE
REC_ID=`echo $LINE | awk -F: '{print $1}'`
do
RUNCNTL=$REC_ID
if (( $1 == $REC_ID ))
then
break
fi
done
echo $RUNCNTL
----------------------------------------
output:
$ ./nishanth1.sh ca_distributed_allocs(Output is blank)
----------------------------------------------

Input file:
cat alloc_runctl_groups.dat
ca_distributed_allocs:CAEMP/EMaaaEE/RENT/
ca_canada:CACAJJKKLLNADA/CANbbbxxxmmmADA
ca_ou_fte:CAOUFTE/FTEzzaa
ca_ou_alloc_stip:CAOUOOKKJJHSTIP/OU ALIKLAYLOCATIONS STIP-ICP#CDOPPYYGGHHUSTIP/OU AKKLLHBYLLOCATIONS

catkin · 04-26-2012, 01:53 AM

Of course it does not work like that. All you had to do was change to the solution given in post 9:

Code:

#!/bin/bash
RUNCNTL=""
export RUNCNTL
BASEDIR=/psoft/batch/fsdev
DATAFILE=$BASEDIR/scripts/alloc_runctl_groups.dat
#cat $DATAFILE | while read LINE
while read LINE
REC_ID=`echo $LINE | awk -F: '{print $1}'`
do
    RUNCNTL=$REC_ID
    if (( $1 == $REC_ID )); then
        break
    fi
#done < $DATAFILE
done < $DATAFILE
echo $RUNCNTL

pan64 · 04-26-2012, 02:04 AM

Quote:

Originally Posted by Kustom42

You need to export the variable inside of the loop not before it.

if you use that RUNCNTL only inside the script you do not need to export it.

nishanthp82 · 04-26-2012, 09:04 AM

you guys rock!!! its working!!!..Thanks