How do I count the number of occurrences of a string in an entire file?

Question

Is there an inbuilt command to do this or has anyone had any luck with a script that does it?

I am looking to count the number of times a certain string (not word) a

Answer 1

This loops over the lines of the file, and on each line finds all occurrences of the string "(*)". Each time that string is found, $c is incremented. When there are no more lines to loop over, the value of $c is printed.

perl -ne'$c++ while /\(\*\)/g;END{print"$c\n"}' filename.txt

Update: Regarding your comment asking that this be converted into a solution that accepts a regex as an argument, you might do it like this:

perl -ne'BEGIN{$re=shift;}$c++ while /\Q$re/g;END{print"$c\n"}' 'regex' filename.txt

That ought to do the trick. If I felt inclined to skim through perlrun again I might see a more elegant solution, but this should work.

You could also eliminate the explicit inner while loop in favor of an implicit one by providing list context to the regexp:

perl -ne'BEGIN{$re=shift}$c+=()=/\Q$re/g;END{print"$c\n"}' 'regex' filename.txt

Answer 2

Using perl's "Eskimo kiss" operator with the -n switch to print a total at the end. Use \Q...\E to ignore any meta characters.

perl -lnwe '$a+=()=/\Q(*)/g; }{ print $a;' file.txt

Script:

use strict;
use warnings;

my $count;
my $text = shift;

while (<>) {
    $count += () = /\Q$text/g;
}

print "$count\n";

Usage:

perl script.pl "(*)" file.txt 

Answer 3

text="(\*)"
grep -o $text file | wc -l

You can make it into a script which accepts arguments like this:

script count:

#!/bin/bash
text="$1"
file="$2"
grep -o "$text" "$file" | wc -l

Usage:

./count "(\*)" file_path

Answer 4

You can use basic grep command:

Example: If you want to find the no of occurrence of "hello" word in a file

grep -c "hello" filename

If you want to find the no of occurrence of a pattern then

grep -c -P "Your Pattern"

Pattern example : hell.w, \d+ etc

Answer 5

You can use basic tools such as grep and wc:

grep -o '(\*)' input.txt | wc -l

Answer 6

I have used below command to find particular string count in a file

grep search_String fileName|wc -l