in reply to Checking number in file name

Whilst (\w+) will match on digits also, you're probably better using ^(\d+); you're also better putting the start marker outside the brackets. Note also that "\w" also accepts "_" characters, so if you know a filename is going to be a certain pattern you are best tying it down as tightly as possible.

Note that also you probably need to look at greedy and non-greedy matching - that initial (\w+) may be getting all the characters

I admit regexs still manage to beat me occasionally and one way of building up patterns is to start at the simplest and incrementally make it more complex. 

1) $filename =~ /^(\d+)_/
2) $filename =~ /^(\d+)_(\d+)/
3) $filename =~ /^(\d+)_(\d+)_(\w+)/
....

[download]

You can also use glob to find all files that match a certain pattern.

If you spot any bugs in my solutions, it's because I've deliberately left them in as an exercise for the reader! :-)

Replies are listed 'Best First'.
Re^2: Checking number in file name
by Anonymous Monk on May 19, 2013 at 15:38 UTC
    The file name could start with some letters as well, here is what I am thinking that could work, since I know that a true file name needs to be at least 7 chars long: 
    #!/usr/bin/perl

use strict;
use warnings;

my @files = qw( 000231263444_01_XY_20130110_061717.txt 17034513_01_WQ_
+20130511_053551.txt 12345670_01_XY_20130110_061717.txt BOA034513_01_W
+Q_20130511_053551.txt);

foreach my $file(@files) {
  
  $file =~/(^\w+)_(\w{1,2})_(\w{1,2})_(\w+)_(\w+)\.txt$/i;
  #my $accountnumber = $1;
  # test
  my $accountnumber = "BOA034513";
 
  if( ($file=~/$accountnumber/gi) && ($accountnumber=~/\w{7,}/g) ) {

    print "\n Found - *$accountnumber* - *$file*\n";

  }else{

    print "\n Not Found - *$accountnumber* - *$file*\n";

   }
   
 }

    [download]
    Any example of how the same process could be done using "GLOB"?
    Thanks!
[reply]
[d/l]

In Section Seekers of Perl Wisdom