匹配模式：正则表达式 - perl

Question

If I want to find in this file all instances of the words USER and PASS and then put the number of times they appear into the two variables respectively, how would I go about that? Thanks!

open MYFILE, '<', 'source_file.txt' or die $!;
open OUTFILE, '>', 'Header.txt' or die $!;

$user = 0;
$pass = 0;

while (<MYFILE>) { 
    chomp;

    my @header = split (' ',$_);
    print OUTFILE "$linenum: @header\n\n";

    if (/USER/ig) {
        $user++;
    }

    if (/PASS/ig) {
        $pass++;
    }
}

Above is the new code and it works. I set my variables equal to 0 and used the ++ incrementor on the variables. But I am still open to suggestions perhaps on expanding my regex's capabilities? (if that makes sense)

Answer 1

You could simply do.

my $user = 0;
my $pass = 0;

while (<MYFILE>) { 
     chomp;
     my @header = split ' ', $_;
     print OUTFILE "$linenum: @header\n\n";

     $user++ if /user/ig;
     $pass++ if /pass/ig;
}