How can I create a path with all of its subdirectories in one shot in Perl?

Question

If you have a path to a file (for example, /home/bob/test/foo.txt) where each subdirectory in the path may or may not exist, how can I create the file foo.txt in a way that uses "/home/bob/test/foo.txt" as the only input instead of creating every nonexistent directory in the path one by one and finally creating foo.txt itself?

Answer 1

You can use File::Basename and File::Path

 use strict;
 use File::Basename;
 use File::Path qw/make_path/;

 my $file = "/home/bob/test/foo.txt";
 my $dir = dirname($file);
 make_path($dir);
 open my $fh, '>', $file or die "Ouch: $!\n"; # now go do stuff w/file

I didn't add any tests to see if the file already exists but that's pretty easy to add with Perl.

Answer 2

Use make_dir from File::Util

   use File::Util;
   my($f) = File::Util->new();
   $f->make_dir('/var/tmp/tempfiles/foo/bar/');

   # optionally specify a creation bitmask to be used in directory creations
   $f->make_dir('/var/tmp/tempfiles/foo/bar/',0755);

Answer 3

I don't think there's a standard function that can do all of what you ask, directly from the filename.

But mkpath(), from the module File::Path, can almost do it given the filename's directory. From the File::Path docs:

The "mkpath" function provides a convenient way to create directories, even if your "mkdir" kernel call won't create more than one level of directory at a time.

Note that mkpath() does not report errors in a nice way: it dies instead of just returning zero, for some reason.

Given all that, you might do something like:

use File::Basename;
use File::Path;

my $fname = "/home/bob/test/foo.txt";

eval {
    local $SIG{'__DIE__'};  # ignore user-defined die handlers
    mkpath(dirname($fname));
};
my $fh;
if ($@) {
    print STDERR "Error creating dir: $@";
} elsif (!open($fh, ">", $fname)) {
    print STDERR "Error creating file: $!\n";
}