CODEWITHSUNDEEP
bash
Todoroff
Todoroff

Reputation: 15

How to search for several strings in log file with bash scripting

I have an issue optimising my bash script. I have few patterns i need to look for in the log file. If one of the patters is listed in the log file then do SOMETHING. So far i have this , but can and how can i optimize it without so many variables:

search_trace() {
    TYPE=$1
    for i in `find ${LOGTRC}/* -prune -type f -name "${USER}${TYPE}*" `
    do
            res1=0 
            res1=`grep -c "String1" $i`                
            res2=0 
            res2=`grep -c "String2" $i`                
            res3=0 
            res3=`grep -c "String3" $i`                
            res4=0 
            res4=`grep -c "String4" $i`
            if [ $res1 -gt 0 ] || [ $res2 -gt 0 ] || [ $res3 -gt 0 ] || [ $res4 -gt 0 ]; then
                    write_log W "Something is done ,because of connection reset in ${i}"
                    sleep 5
            fi
    done

Upvotes: 1

Views: 72

Answers (2)

Eugene Yarmash
Eugene Yarmash

Reputation: 149806

You could simply use alternation syntax in the regular expression you pass to grep, e.g.

if grep -q -E '(String1|String2|String3|String4) filename'; then
    # do something
fi

The -E option makes grep use extended regular expressions (including the alternation (|) operator).

Upvotes: 1

glenn jackman
glenn jackman

Reputation: 246827

search_trace() {
    find "$LOGTRC"/* -prune -type f -name "$USER${1}*" |
    while IFS= read -r filename; do
        if grep -q -e String1 -e String2 -e String3 -e String4 "$filename"; then
            write_log W "Something is done ,because of connection reset in $filename"
            sleep 5
        fi
    done
}

grep's -q option is good for use in an if-condition: it is efficient since it will exit successfully when it finds the first match -- it doesn't have to read the rest of the file.

Upvotes: 0

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