Qfyilyi

i'm writing a basic Perl script to check if there're files in certain directories their names contain today's date, the script works fine when there are files in the directory and returns TRUE, but doesn't return FALSE when no files withe the given criteria exist

the script is as below:

#!/usr/bin/perl -w

use POSIX qw(strftime);

my $datestring = strftime "%Y%m%d", localtime;

opendir(DIR, 'C:Perl');

@files = grep (/$datestring/,readdir(DIR));

closedir(DIR);

foreach $file (@files) {

    my $count = () = $file =~ /$datestring/;

    if ($count > 0) {

        print ("TRUE");

    }

    else 

    {

        print ("FALSE");

    }

}

the files names are like

export_opportunities_20181111-040005_20181124-040010.csv

export_opportunities_20181111-040005_20181122-040010.csv

You can use @files in scalar context to tell if grep returned any matches from readdir. In scalar context, @files is the number of elements in the array.

@files = grep (/$datestring/,readdir(DIR));

# this is more commonly written

#   @files = grep {/$datestring/} readdir(DIR);   



print @files > 0 ? "TRUE" : "FALSE";

# or

print scalar(@files)." files matched $datestring";

See also List::Util.

use v5.10;    

use List::Util qw<all any none>;

###

@files = readdir(DIR);

say 'all match' if all {/$datestring/} @files;

say 'at least one match' if any {/$datestring/} @files;

say 'no matches' if none {/$datestring/} @files;

As commented by toolic, when you are already removing non-matching files here :

@files = grep (/$datestring/,readdir(DIR));

Hence your for loop will never see non-matching files.

Here are a few other comments on your code :

• always use strict and use warnings (there are several variables in your code snippet which are not properly declared)




• always check the return code of system calls such as opendir




• you can use the smartmatch operator in boolean context instead of assigning to the $count variable




• you don't need to use parentheses around argument to the built-in print function

Here is a cleaner version of your code :

#!/usr/bin/perl -w

use strict;

use warnings;

use POSIX qw(strftime);



my $datestring = strftime "%Y%m%d", localtime;

opendir(DIR, 'C:Perl') or die "cannot open dir : $!";

my @files = readdir(DIR);

closedir(DIR);



foreach my $file (@files) {

    if ($file =~ /$datestring/) {

        print "TRUEn";

    } else {

        print "FALSEn";

    }

}