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Recursively copy multi - level directories

Use File::Find module to recursively copy multi-level directories.

use strict;
use warnings;
use File::Path 'mkpath';
use Fcntl;
use File::Find 'find';
use File::Copy 'copy';
use Cwd 'getcwd';

# Preparation (Creating directories and files)
my $top_dir = "dir_20080601_$$";
my @dirs = (
  "$top_dir/dir1", "$top_dir/dir1/dir1_1", "$top_dir/dir1/dir1_2",
  "$top_dir/dir2",
);
for my $dir (@dirs) {
  eval {mkpath $dir};
  if (@!) {die "@!"}
}

my @files = (
  "$top_dir/top.txt", "$top_dir/dir1/1.txt",
  "$top_dir/dir1/dir1_1/1_1.txt", "$top_dir/dir1/dir1_2/1_2.txt",
  "$top_dir/dir2/2.txt"
);
for my $file (@files) {
  sysopen(my $fh, $file, O_WRONLY | O_CREAT | O_EXCL)
    or die "Unable to create $file .:$!";
  close $fh;
}
print "Preparation: $top_dir has been created.\n\n";

# Recursive directory copy example
print "1: Copy directory recursively.\n";

my $cur_dir = getcwd ();
# File::Find internally repeats chdir, so
# Create a copy destination directory name with an absolute path.
my $dir_copy_to = "$cur_dir/dir_20080601_ ${$} _ cp";

find(\&recursive_copy, $top_dir);
print "$top_dir has been copied to $dir_copy_to.\n";

# Function for recursive copying
sub recursive_copy {
  # Copy source file or directory
  my $file_from = $_;

  # The top directory of the copy source
  # In the top directory of the copy destination
  # Replace.
  my $file_to = $File::Find::name;
  $file_to =~ s #^$top_dir # $dir_copy_to # ;
                                        
  if (-d $file_from) {
    # The directory cannot be copied, so create it with the same name.
    mkdir $file_to
      or die "Unable to create $file_to.\n";
  }
  else {
    copy $file_from, $file_to
      or die "Unable to copy $file_from to $file_to.\n";
  }
}

(Reference) File::Path, File::Copy, eval, sysopen function, Fcntl

Recursively copy multi - level directories

find(\&recursive_copy, $top_dir);

# Function for recursive copying
sub recursive_copy {
  # Copy source file or directory
  my $file_from = $_;

  # The top directory of the copy source
  # In the top directory of the copy destination
  # Replace.
  my $file_to = $File::Find::name;
  $file_to =~ s #^$top_dir # $dir_copy_to # ;
                                        
  if (-d $file_from) {
    # The directory cannot be copied, so create it with the same name.
    mkdir $file_to
      or die "Unable to create $file_to.\n";
  }
  else {
    copy $file_from, $file_to
      or die "Unable to copy $file_from to $file_to.\n";
  }
}

To copy a directory recursively, use the File::Find module to repeatedly create the directory and copy the file. Since the configuration other than the top directory is the same as the copy source, only the top directory name is replaced.

Since the directory cannot be copied, we will create it with the name of the copy destination.