Get names of all the directories with similar naming pattern in Perl - perl

Question

I have a directory "logs" which contains sub-directories as "A1", "A2", "A3", "B1", "B2", "B3".
I want to write a perl code that search all the sub directories with name pattern as "A", i.e. all the directories names starting from character A.
Please help me.

Answer 1

Use the Perl core module File::Find:
use strict;
use warnings;
use File::Find;
#Find in 'logs' directory, assume the script is executed at this folder level
find(\&wanted, 'logs');
sub wanted {
#Subroutine called for every file / folder founded ($_ has the name of the current)
if(-d and /^A/ ) {
print $_, "\n";
}
}
Update:
If you want to parametrize the prefix, you can do this:
use strict;
use warnings;
use File::Find;
my $prefix = 'B';
find(\&wanted, 'logs');
sub wanted {
if(-d and /^$prefix/ ) {
print $_, "\n";
}
}

Answer 2

File::Find is overkill for simply searching a directory. opendir/readdir still has a purpose!
This program does a chdir to the specified directory so that there is no need to build the full path from the names generated by readdir.
The directory to search and the required prefix can be passed as command-line parameters and will default to logs and A if they are not supplied.
use strict;
use warnings;
use autodie;
my ($dir, $prefix) = #ARGV ? #ARGV : qw/ logs A /;
chdir $dir;
my #wanted = do {
opendir(my $dh, '.');
grep { -d and /^\Q$prefix/ } readdir $dh;
};
print "$_\n" for #wanted;