How can I list files under a directory with a specific name pattern using Perl? - perl

Question

I have a directory /var/spool and inside that, directories named
a b c d e f g h i j k l m n o p q r s t u v x y z
And inside each "letter directory", a directory called "user" and inside this, many directories called auser1 auser2 auser3 auser4 auser5 ...
Every user directory contains mail messages and the file names have the following format: 2. 3. 4. 5. etc.
How can I list the email files for every user in every directory in the following way:
/var/spool/a/user/auser1/11.
/var/spool/a/user/auser1/9.
/var/spool/a/user/auser1/8.
/var/spool/a/user/auser1/10.
/var/spool/a/user/auser1/2.
/var/spool/a/user/auser1/4.
/var/spool/a/user/auser1/12.
/var/spool/b/user/buser1/12.
/var/spool/b/user/buser1/134.
/var/spool/b/user/buser1/144.
etc.
I need that files and then open every single file for modify the header and body. This part I already have, but I need the first part.
I am trying this:
dir = "/var/spool";
opendir ( DIR, $dir ) || die "No pude abrir el directorio $dirname\n";
while( ($filename = readdir(DIR))){
#directorios1 = `ls -l "$dir/$filename"`;
print("#directorios1\n");
}
closedir(DIR);
But does not work the way I need it.

Answer 1

You can use File::Find.

Answer 2

As others have noted, use File::Find:
#!/usr/bin/perl
use strict;
use warnings;
use File::Find;
find(\&find_emails => '/var/spool');
sub find_emails {
return unless /\A[0-9]+[.]\z/;
return unless -f $File::Find::name;
process_an_email($File::Find::name);
return;
}
sub process_an_email {
my ($file) = #_;
print "Processing '$file'\n";
}

Answer 3

Use File::Find to traverse a directory tree.

Answer 4

For a fixed level of directories, sometimes it's easier to use glob than File::Find:
while (my $file = </var/spool/[a-z]/user/*/*>) {
print "Processing $file\n";
}

Answer 5

People keep recommending File::Find, but the other piece that makes it easy is my File::Find::Closures, which provides the convenience functions for you:
use File::Find;
use File::Find::Closures qw( find_by_regex );
my( $wanted, $reporter ) = find_by_regex( qr/^\d+\.\z/ );
find( $wanted, #directories_to_search );
my #files = $reporter->();
You don't even need to use File::Find::Closures. I wrote the module so that you could lift out the subroutine you wanted and paste it into your own code, perhaps tweaking it to get what you needed.

Answer 6

Try this:
sub browse($);
sub browse($)
{
my $path = $_[0];
#append a / if missing
if($path !~ /\/$/)
{
$path .= '/';
}
#loop through the files contained in the directory
for my $eachFile (glob($path.'*'))
{
#if the file is a directory
if(-d $eachFile)
{
#browse directory recursively
browse($eachFile);
}
else
{
# your file processing here
}
}
}#browse