CODEWITHSUNDEEP
linuxscriptingawk
Ste Prescott
Ste Prescott

Reputation: 1817

Awk Search file for string

I have implimented a function that searches a column in a file for a string and it works well. What I would like to know how do I modify it to search all the columns fr a string?

awk -v s=$1 -v c=$2 '$c ~ s { print $0 }' $3

Thanks

Upvotes: 0

Views: 5813

Answers (3)

SHAILESH PATEL
SHAILESH PATEL

Reputation: 71

awk -v pat="$string" '$0 ~ pat' infile

Upvotes: 0

Dennis Williamson
Dennis Williamson

Reputation: 359905

Here is an example of one way to modify your current script to search for two different strings in two different columns. You can extend it to work for as many as you wish, however for more than a few it would be more efficient to do it another way.

awk -v s1="$1" -v c1="$2" -v s2="$3" -v c2="$4"  '$c1 ~ s1 || $c2 ~ s2 { print $0 }' "$5"

As you can see, this technique won't scale well.

Another technique treats the column numbers and strings as a file and should scale better:

awk 'FNR == NR {strings[++c] = $1; columns[c] = $2; next}
     {
         for (i = 1; i <= c; i++) {
             if ($columns[i] ~ strings[i]) {
                 print
             }
         }
     }' < <(printf '%s %d\n' "${searches[@]}") inputfile

The array ${searches[@]} should contain strings and column numbers alternating.

There are several ways to populate ${searches[@]}. Here's one:

#!/bin/bash
# (this is bash and should precede the AWK above in the script file)
unset searches
for arg in "${@:1:$#-1}"
do
    searches+=("$arg")
    shift
done
inputfile=$1   # the last remaining argument
# now the AWK stuff goes here

To run the script, you'd do this:

$ ./scriptname foo 3 bar 7 baz 1 filename

Upvotes: 0

Adam Liss
Adam Liss

Reputation: 48280

If "all the columns" means "the entire file" then:

grep $string $file

Upvotes: 3

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