Re^3: file modifications using file::find

"Ken, I like your code!"

Thanks. I appreciate the compliment.

'You snuck in the tests like "-z _".'

Unfortunately, the OP gave very little information about Perl experience or, indeed, File::Find usage requirements. As this was a first post, I didn't make a big deal about it; although, I did provide a link "for information on how you can help us to help you".

My main aim was to provide the requested "help or a tutorial". I did consider including an explanation for the special filehandle, '_'; however, as I didn't know if these tests would be used, I chose to add a link to that information. I did use the link text "file tests", in case "-X" was too cryptic. :-)

"About cwd"

The last paragraph of my post did include a warning about specifying directories; an explanation that I'd only used Cwd for my example code; and, suggested a number of better alternatives. Furthermore, I only used the getcwd() function to generate the required @directories_to_search for find(); there was no explicit changing of directories in my script.

Of course, there is the implicit changing of directories as part of File::Find's default behaviour. You can change that: see "File::Find - %options - no_chdir".

Your comments regarding using an array are sound. You may actually want to use the list more than once. I assume you know how to do this, but for the OP or anybody else, here's a very basic (partial) code example:

...
find(\&wanted, @dirs);
do_something_with(get_found_files());
check_something_done_with(get_found_files());
...
{
    my @found_files;

    sub get_found_files { return @found_files }

    sub wanted {
        ...
        push @found_files, $File::Find::name;
        ...
    }
}
[download]

Note that the anonymous block makes @found_files (lexically) private: only get_found_files() and wanted() have access to it. You can, of course, modify the list returned, but the original will stay intact. For anyone unfamiliar with this concept, see "perlsub: Private Variables via my()" for a more in-depth discussion of this topic.

— Ken

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Re^4: file modifications using file::find by Marshall (Canon) on Jul 26, 2021 at 01:21 UTC
Hi kcott! Yes, my reply to your post was meant to be a compliment. I have no idea of what the OP is trying to accomplish. There is a huge amount that is left unsaid. As a very simple example, I present this code (create found, populate found, do something with found): #!/usr/bin/perl use strict; use warnings; use File::Find; # lists all "normal files" which are both readable and # writeable underneath "C:/test" my @found; find( { wanted => \&get_files }, "C:/test" ); print "$_\n" for @found; sub get_files { return unless ( -f $File::Find::name and -r _ and -w _); push @found, $File::Find::name; } __END__ printed on my machine: Note that the sub directory of "subdirtest" is skipped. A directory name fails the -f test. C:/test/maur-1110.tiff C:/test/maur-1111.psd C:/test/TUMI-1354839054_alt1_.psd C:/test/subdirtest/docinbsubdir.txt C:/test/subdirtest/New Text Document.txt [download]	[reply] [d/l]

Replies are listed 'Best First'.

Re^4: file modifications using file::find
by Marshall (Canon) on Jul 26, 2021 at 01:21 UTC

kcott

Yes, my reply to your post was meant to be a compliment.

I have no idea of what the OP is trying to accomplish. There is a huge amount that is left unsaid.

As a very simple example, I present this code (create found, populate found, do something with found):

#!/usr/bin/perl
use strict;
use warnings;

use File::Find;

# lists all "normal files" which are both readable and
# writeable underneath "C:/test"

my @found;

find( { wanted => \&get_files }, "C:/test" );

print "$_\n" for @found;


sub get_files 
{  
   return unless ( -f $File::Find::name and -r _ and -w _);
   
   push @found, $File::Find::name;
}        

__END__
printed on my machine:
Note that the sub directory of "subdirtest" is skipped.
A directory name fails the -f test.

C:/test/maur-1110.tiff 
C:/test/maur-1111.psd 
C:/test/TUMI-1354839054_alt1_.psd 
C:/test/subdirtest/docinbsubdir.txt 
C:/test/subdirtest/New Text Document.txt
[download]

[reply]
[d/l]