How can I list all files in a directory using Perl?
I usually use something like
my $dir="/path/to/dir";
opendir(DIR, $dir) or die "can't open $dir: $!";
my @files = readdir DIR;
closedir DIR;
or sometimes I use glob
, but anyway, I always need to add a line or two to filte开发者_运维问答r out .
and ..
which is quite annoying.
How do you usually go about this common task?
my @files = grep {!/^\./} readdir DIR;
This will exclude all the dotfiles as well, but that's usually What You Want.
I often use File::Slurp. Benefits include: (1) Dies automatically if the directory does not exist. (2) Excludes .
and ..
by default. It's behavior is like readdir
in that it does not return the full paths.
use File::Slurp qw(read_dir);
my $dir = '/path/to/dir';
my @contents = read_dir($dir);
Another useful module is File::Util, which provides many options when reading a directory. For example:
use File::Util;
my $dir = '/path/to/dir';
my $fu = File::Util->new;
my @contents = $fu->list_dir( $dir, '--with-paths', '--no-fsdots' );
I will normally use the glob
method:
for my $file (glob "$dir/*") {
#do stuff with $file
}
This works fine unless the directory has lots of files in it. In those cases you have to switch back to readdir
in a while
loop (putting readdir
in list context is just as bad as the glob
):
open my $dh, $dir
or die "could not open $dir: $!";
while (my $file = readdir $dh) {
next if $file =~ /^[.]/;
#do stuff with $file
}
Often though, if I am reading a bunch of files in a directory, I want to read them in a recursive manner. In those cases I use File::Find
:
use File::Find;
find sub {
return if /^[.]/;
#do stuff with $_ or $File::Find::name
}, $dir;
If some of the dotfiles are important,
my @files = grep !/^\.\.?$/, readdir DIR;
will only exclude .
and ..
When I just want the files (as opposed to directories), I use grep
with a -f
test:
my @files = grep { -f } readdir $dir;
Thanks Chris and Ether for your recommendations. I used the following to read a listing of all files (excluded directories), from a directory handle referencing a directory other than my current directory, into an array. The array was always missing one file when not using the absolute path in the grep statement
use File::Slurp;
print "\nWhich folder do you want to replace text? " ;
chomp (my $input = <>);
if ($input eq "") {
print "\nNo folder entered exiting program!!!\n";
exit 0;
}
opendir(my $dh, $input) or die "\nUnable to access directory $input!!!\n";
my @dir = grep { -f "$input\\$_" } readdir $dh;
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