Grep inside bash script not finding item

Question

I have a script which is checking a key in one file against a key in another to see if it exists in both. However in the script the grep never returns anything has been found but on the command line it does.

#!/bin/bash
# First arg is the csv file of repo keys separated by line and in
# this manner 'customername,REPOKEY'
# Second arg is the log file to search through

log_file=$2
csv_file=$1
while read line;
do 
    customer=`echo "$line" | cut -d ',' -f 1`
    repo_key=`echo "$line" | cut -d ',' -f 2`
    if [ `grep "$repo_key" $log_file` ]; then
        echo "1"
    else
        echo "0"
    fi
done < $csv_file

The CSV file is formatted as follows:

customername,REPOKEY

and the log file is as follows:

REPOKEY

etc

I call the script by doing ./script csvfile.csv logfile.txt

anubhava · Accepted Answer · 2014-10-16 16:08:34Z

2

Rather then checking output of grep command use grep -q to check its return status:

if grep -q "$repo_key" "$log_file"; then
    echo "1"
else
    echo "0"
fi

Also your script can be simplified to:

log_file=$2
csv_file=$1
while IFS=, read -r customer repo_key; do
    if grep -q "$repo_key" "$log_file"; then
        echo "1"
    else
        echo "0"
    fi
done < "$csv_file"

answered Oct 16, 2014 at 16:08

anubhava

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2 Comments

Rob Over a year ago

Hmm, changing this still didn't change my original result, it's like the grep isn't working inside the script?

anubhava Over a year ago

Just before grep insert echo "[$repo_key]" and tell me what value do you get

nu11p01n73R · Accepted Answer · 2014-10-16 16:09:09Z

0

use the exit status of the grep command to print 1 or 0

repo_key=`echo "$line" | cut -d ',' -f 2`

grep -q "$repo_key" $log_file

if [ $? -eq 1  ]; then
        echo "1"
    else
        echo "0"
    fi

-q supresses the output so that no output is printed

$? is the exit status of grep command 1 on successfull match and 0 on unsuccessfull

you can have a much simpler version as

grep -q "$repo_key" $log_file
echo $?

which will produce the same output

answered Oct 16, 2014 at 16:09

nu11p01n73R

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