Pattern Matching

[sadanand]

I have a code which displays the list of files avaialble in a particular folder.

Example:-

I have 123,123_SIM,456_SIM,678_SIM,890 files in the following folder.
C:\perl_practice\Folder

Code:-

use Data::Dumper;
#use strict;
#use warnings;
use File::Find;
use File::Stat;
use Time::Local;
 
my $test_data1='C:\perl_practice\Folder';
 
my @cbr;
 
@cbr = $test_data1;
 
foreach $cbr (@cbr) {
    opendir(DIR,$cbr);
    @files = readdir(DIR);
    closedir(DIR);
    foreach $file (sort @files) {
        print("$file \n");
    }
}
 

When I execute this program.All the files available in the C:\perl_practice\Folder are diplayed.

plat_USb
ICON_SIM
MYCO_SIM
SAME_SIM
TIME_cable
GURU_JA
JVA_TEX
 

But I want display only those files which contain SIM word in the file name.
like

ICON_SIM
MYCO_SIM
SAME_SIM
 

Waiting for ur valuable response

Regards,
Sada

[miller]

Hi Sada,

First off, never comment out "use strict;". It's during development that you need it most, so do yourself a favor and always leave it in.

Cleaning up your code a little bit.

use strict;
 
my $test_data1='C:/perl_practice/Folder';
 
my @cbr = $test_data1;
 
foreach my $cbr (@cbr) {
    opendir(DIR, $cbr) or die "Can't open $some_dir: $!";
    my @files = readdir(DIR);
    closedir(DIR);
 
    foreach my $file (sort @files) {
        print "$file \n" if $file =~ /SIM$/;
    }
}
 

- Miller

[prn]

Another plausible idiom:

use strict;
 
my $pattern = "SIM";
my $test_data1='C:/perl_practice/Folder';
 
my @cbr = $test_data1;
 
foreach my $cbr (@cbr) {
    opendir (DIR, $cbr) or die "Could not open $cbr for read: $! \n";
    @files = grep /$pattern/, readdir(DIR);
    closedir (DIR);
 
    foreach my $file (sort @files) {
        print "$file \n";
    }
}
 

The potential advantage of using grep to limit the array of files is that @files now contains only the files you are interested in and you don't have to limit them again. Whether this is an actual advantage depends on what you want to do.

As usual, there's more than one way to do it. :)

HTH,
Paul

[prn]

OBTW, you (sada) initially said:

I have a code which displays the list of files avaialble in a particular folder.

But the code you gave looks like it is intended to search through a larger number of folders and you just gave one of them. Now this is plausible in a demo, but just in case you actually meant "a particular folder" rather than "a number of folders" you could simplify your code considerably by eliminating @cbr, the array of folders. If you are just simplifying and meant a bunch of folders, then never mind.

Best Regards,
Paul

[KevinADC]

in the spirit of TIMTOWTDI

use strict;
my $pattern = "SIM";
my $test_data1='C:/perl_practice/Folder/';
print "$_\n" for sort <$test_data1*$pattern>;

[prn]

Oh, yeah! Nice one, Kevin!

For Sada: to understand Kevin's version, read about the "Filename Globbing Operator" (pp. 83-85 in the Camel Book 3rd edition).

<runs off to think about the whys and wherefores of readdir vs. filename globbing>

:)

Paul