I'm not sure what you mean by "commit", are you doing some database work? The following is a very basic example for (one way of) checking for spaces within strings:

#!/usr/bin/perl

use strict;
use warnings;

my $path;

$path = "/usr/bin";
#$path = "/usr/bin foo"; # uncomment for testing

if ( $path =~ /\s/){
    print "String $path contains a space character.\n";
}else{
    print "String $path does not contain a space character.\n";
}
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See perlrequick.