Pattern matching and setting the match to a variable

mrbbq has asked for the wisdom of the Perl Monks concerning the following question:

Hello Monks, this question is probably rudimentary but I can not seem to figure it out on my own. I have a file and in it is a bunch of paths like this: "\\my.domain.net\Apps\Sketchup" "\\fs-10\licenses\Sketchups" and so fourth - there are alot of lines in this file. I am trying to write a script that takes standard in like ./script.pl "Apps\Sketchup" and then matches the line in the file and sets the first column to one variable and the second colums to another variable sans the quotes. But I am stuck on the matching at this point. Here is my script so far:

$my_default="\\\\my\.domain\.net\\";
$my_file="info.txt";
my $path = shift @ARGV;


sub usage{
        print STDERR "\nUsage:\n";
        print STDERR "\t$0 \"the\path\"\n";
        print "\n";
}

sub grep_pattern{
       # print "$patten\n";
        foreach (@my_data)
        {print "$_\n" if /$pattern/;
        }
print "\n\n";
}

sub print_array{
        for ($i=0; $i<=$#my_data;$i++)
        {print $my_data[$i], "\n";
        }
print "\n\n";
}

unless ($path){
        &usage;
        exit (-1);
}


open(HANDLE, $my_file) || die("Open the file failed!");
@my_data=<HANDLE>;

print_array;

# Try and find the ARGV
$pattern = $path;
print "Searching for: $pattern\n";
grep_pattern;
[download]

At this point I cant even get a match. Can one of you Monks point me in the right direction. Thanks in advance

Comment on Pattern matching and setting the match to a variable Download Code

Replies are listed 'Best First'.
Re: Pattern matching and setting the match to a variable by kyle (Abbot) on Feb 15, 2008 at 22:10 UTC
Things like `\S` in your "pattern" are being interpreted as regular expressions. You should quotemeta before using the string as a pattern. This is also the same as doing `/\Q$pattern/` for a pattern. If you're just matching literal strings, though, index would be a good way to go.	[reply] [d/l] [select]
Re^2: Pattern matching and setting the match to a variable by mrbbq (Sexton) on Feb 15, 2008 at 22:20 UTC
THat worked perfectly! `{print "$_\n" if /\Q$pattern/;` [download] Thanks to all who replied.	[reply] [d/l]
Re: Pattern matching and setting the match to a variable by starX (Chaplain) on Feb 15, 2008 at 22:09 UTC
Try checking regular expression return values. Given this: `my $line = "I am the very model of a modern major general."; my $good_match = $line =~ m/major/; my $bad_match = $line =~ m/corporal/; print "$line\n" if $good_match == 1; # Prints the line. print "$line\n" if $bad_match == 1; # Doesn't print anything.` [download] A successful regular expression match will return 1, so you can check against that. It prints the line if the match was made, and doesn't if it wasn't. Update: Whoops, missed that you were doing that implicitly. Kyle has the correct answer. --starX www.axisoftime.com	[reply] [d/l]
Re: Pattern matching and setting the match to a variable by ikegami (Patriarch) on Feb 16, 2008 at 19:53 UTC
`for (my $i=0; $i<=$#my_data;$i++)` [download] isn't as clear as (and no more efficient than) `for my $i (0 .. $#my_data)` [download] And more specifically, `for ($i=0; $i<=$#my_data;$i++) {print $my_data[$i], "\n"; }` [download] can simply be written as `for (@my_data) {print $_, "\n"; }` [download]	[reply] [d/l] [select]