How to find files/folders recursively in Perl script? - perl

Question

I have a perl script which I have written to search files present in my windows folders, recursively. I enter the search text as the perl script runtime argument to find a file having this text in it's name. The perl script is as below:
use Cwd;
$file1 = #ARGV[0];
##res1 = glob "*test*";
##res1 = glob "$file1*";
#res1 = map { Cwd::abs_path($_) } glob "$file1*";
foreach (#res1)
{
print "$_\n";
}
But this is not searching all the sub-directories recursively. I know glob doesn't match recursively.
So tried using module File::Find and the function find(\&wanted, #directories);
But I got a error saying find() undefined. From what I read from help, I thought find() function is defined by default in Perl installation, with some basic code to find folders/files. Isn't it correct?
Questions is, in the above perl script, how do I search for files/folders recursively?
Second questions, I found that perldoc <module> help does not have examples about using a certain function in that module, which would make it clear.
Can you point to some good help/document/book for using various perl functions from different perl modules with clear examples of usage of those module functions.

Answer 1

Another excellent module to use is File::Find::Rule which hides some of the complexity of File::Find while exposing the same rich functionality.
use File::Find::Rule;
use Cwd;
my $cwd = getcwd();
my $filelist;
sub buildFileIndex {
open ($filelist, ">", "filelist.txt") || die $!;
# File find rule
my $excludeDirs = File::Find::Rule->directory
->name('demo', 'test', 'sample', '3rdParty') # Provide specific list of directories to *not* scan
->prune # don't go into it
->discard; # don't report it
my $includeFiles = File::Find::Rule->file
->name('*.txt', '*.csv'); # search by file extensions
my #files = File::Find::Rule->or( $excludeDirs, $includeFiles )
->in($cwd);
print $filelist map { "$_\n" } #files;
return \$filelist;
}

Answer 2

These two pages are all you need to study:
File::Find documentation
Beginners guide to File::Find

Answer 3

If you don't mind using cpan module, Path::Class can do the work for you:
use Path::Class;
my #files;
dir('.')->recurse(callback => sub {
my $file = shift;
if($file =~ /some text/) {
push #files, $file->absolute->stringify;
}
});
for my $file (#files) {
# ...
}

Answer 4

An alternative would be to use find2perl to create the start of the script for you. It can turn a find command like,
find . -type f -name "*test*" -print
To an equivalent perl script. You just put find2perl instead of find. It uses File::Find under the hood but gets you going quickly.

Answer 5

use 5.010; # Enable 'say' feature
use strict;
use warnings;
use File::Find; # The module for 'find'
find(\&wanted, #ARGV); # #ARGV is the array of directories to find.
sub wanted {
# Do something...
# Some useful variables:
say $_; # File name in each directory
say $File::Find::dir; # the current directory name
say $File::Find::name; # the complete pathname to the file
}
Example for listing driver modules on Linux (Fedora):
use 5.022;
use strict;
use warnings;
use POSIX qw(uname);
use File::Find;
my $kernel_ver = (uname())[2];
my #dir = (
"/lib/modules/$kernel_ver/kernel/drivers"
);
find(\&wanted, #dir);
sub wanted {
say if /.*\.ko\.xz/;
}