perl function m

In Perl, the m function (short for "match") is used to search a string for a pattern specified by a regular expression. Here's an example that demonstrates how to use m:

#!/usr/bin/perl

use strict;
use warnings;

my $string = "The quick brown fox jumps over the lazy dog.";

if ($string =~ m/quick/) {
    print "Found 'quick' in string.\n";
}

if ($string =~ m/dog/) {
    print "Found 'dog' in string.\n";
}

if ($string =~ m/cat/) {
    print "Found 'cat' in string.\n";
} else {
    print "Did not find 'cat' in string.\n";
}

In this example, we define a string containing the phrase "The quick brown fox jumps over the lazy dog." We then use the m function to search for three different patterns within the string.

The first if statement checks whether the string contains the pattern "quick". Because it does, the statement prints the message "Found 'quick' in string." to the console.

The second if statement checks whether the string contains the pattern "dog". Because it does, the statement prints the message "Found 'dog' in string." to the console.

The third if statement checks whether the string contains the pattern "cat". Because it does not, the statement executes the else block, which prints the message "Did not find 'cat' in string." to the console.

Note that the m function is often used in conjunction with regular expressions, which are a powerful way to search for patterns within strings. The regular expression is specified using forward slashes, as in the examples above.