CODEWITHSUNDEEP
perlfile
jms1980
jms1980

Reputation: 1075

Checking to see if any .txt files exist in a directory using a Perl script

I have a directory, /home/textfile/.

I want to use a Perl script to check to see if *.txt file exist in this directory or not. If they do, I want to have it say "Text files exist". Otherwise, if there are no text files in the directory I want it to say "No text files exist".

The text files could have any name. I just want to check if there is a text file in that directory, /home/textfile.

Below is the script I am trying to use:

$filedir = "/home/textfile/";
chdir($filedir);
if (-e "`ls *.txt`")
{
    print STDOUT "Text file exist"
}
else
{
    print STDOUT "No text file exist"
}

How can I fix this script so it will do what I am looking for it to do?

Upvotes: 0

Views: 2154

Answers (2)

Hunter McMillen
Hunter McMillen

Reputation: 61510

From perldoc about the -X file test operators:

A file test, where X is one of the letters listed below. This unary operator takes one argument, either a filename, a filehandle, or a dirhandle, and tests the associated file to see if something is true about it.

In wrapping the ls command in double quotes, you are hoping to test the filenames that are returned by ls, but in reality you are testing for the existence of a file named 'ls *.txt'.

There are a couple of options. You could use ls in a separate step to get all of the text file names and then test for the existence of a single one.

my @text_files = `ls *.txt`;
chomp(@text_files);

if ( -e $text_files[0] ) {
   ...
}
else {
   ...
}

But since ls will only return existing files, the -e check here is not needed at all. You can simply say:

my @text_files = `ls *.txt`;
if ( @text_files ) {
    print "Text file exist"
}
else {
    print "No Text file exist"
}

I should also note that, since you don't use $dir in your ls command, you are not actually looking in the $dir directory but the current working directory. You would need to add $dir to the ls command:

my @text_files = `ls $dir/*.txt`;
if ( @text_files ) {
    print "Text file exist"
}
else {
    print "No Text file exist"
}

Alternatively, you can use the glob builtin instead of shelling out to ls and let Perl manage how to actually read the files. This is generally the more robust and maintainable solution:

my @text_files = glob("$dir/*.txt");
if ( @text_files ) {
    print "Text file exist"
}
else {
    print "No Text file exist"
}

Upvotes: 0

Borodin
Borodin

Reputation: 126732

It's simplest to use glob to get a list of all files ending with .txt in that directory. It avoids shelling out to use ls

Like this

use strict;
use warnings;

my $dir = '/home/textfile';
my @files = glob "$dir/*.txt";

print "No " unless @files;
print "Text file exist\n";

Upvotes: 3

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