manishrathi has asked for the wisdom of the Perl Monks concerning the following question:

I am trying a simple code of reading dir content and printing it on cmd prompt. But its not working. What can be problem in here ? 
opendir (dir, "C:\Users\Admin\Desktop\Staples files");
@dir_content = readdir(dir);
closedir(dir);

for $d(@dir_content){
    print "$d ";
}

[download]
This code does not give any error nor does it print output

I have tried it in different ways as follows 
opendir dir, "C:\Users\Admin\Desktop\Staples files\";
my @files = readdir(dir);
closedir(dir);

foreach $file(@files){
    print "$file \n";
}
print $#files ;

[download]
I am getting following errors when I run this code

C:\Users\Admin>perl C:\Users\Admin\Desktop\perl_programs\printDir.pl Scalar found where operator expected at C:\Users\Admin\Desktop\perl_programs\pri ntDir.pl line 6, near "print "$file" (Might be a runaway multi-line "" string starting on line 1) (Do you need to predeclare print?) Backslash found where operator expected at C:\Users\Admin\Desktop\perl_programs\ printDir.pl line 6, near "$file \" (Missing operator before \?) String found where operator expected at C:\Users\Admin\Desktop\perl_programs\pri ntDir.pl line 6, at end of line (Missing semicolon on previous line?) syntax error at C:\Users\Admin\Desktop\perl_programs\printDir.pl line 6, near "p rint "$file " Can't find string terminator '"' anywhere before EOF at C:\Users\Admin\Desktop\p erl_programs\printDir.pl line 6. 
 open file, "< C:\Users\Admin\Desktop\staples\readfile.txt";
@file_content = <file>;
for $f (@file_content){
    print "$f \n";
}

[download]
This code does not give anu errors. but does not print content of files either.

Replies are listed 'Best First'.
Re: Reading DIR content and printing it
by Corion (Patriarch) on Jul 17, 2011 at 10:35 UTC

    The backslash is special within strings. See perlop. If you had run your code with warnings enabled, Perl would have told you so:

    Unrecognized escape \A passed through at -e line 1.
Unrecognized escape \D passed through at -e line 1.
Unrecognized escape \S passed through at -e line 1.

    [download]

    Either properly escape the backslash (see perlop, or use forward slashes to separate the directories.

[reply]
[d/l]
      Thanks, And why would I not get output, when there is no "\" ?
      open file, "< readfile.txt";

@filecontent = <file>;
for $f (@filecontent){
print "$f \n" ;
}
close file;

      [download]
[reply]
[d/l]

        In addition to checking for errors, $f has a newline at its end. Again, if you had used warnings, Perl would have told you so:

        Unsuccessful open on filename containing newline at -e line 1.

        [download]

        Also, when printing out values, always put delimiters around them so you see whitespace:

        print "[$f]\n";

        [download]
[reply]
[d/l]
[select]
        check for errors:
        open file, "< readfile.txt"
  or die "Unable open file: $!";

        [download]
[reply]
[d/l]
Re: Reading DIR content and printing it
by Khen1950fx (Canon) on Jul 17, 2011 at 14:13 UTC
    I usually try to recursively read directory content. This script will print to STDOUT each subdirectory and files in each subdirectory of your chosen directory: 
    #!/usr/bin/perl

use strict;
use warnings;

my $dir = '/usr/lib/perl5/5.8.8/CGI';

@ARGV = $dir unless @ARGV;
use File::Find;
find sub { print $File::Find::name, -d &&  $dir, "\n" }, @ARGV;

    [download]
    Note that neither opendir, readdir, nor File::Find will print the "contents" of the files, just the names thereof.
[reply]
[d/l]
Re: Reading DIR content and printing it
by perlaintdead (Scribe) on Jul 18, 2011 at 05:45 UTC

    here's my solution 

    opendir(DIR, "\.");
@filelist = readdir(DIR); 
closedir(DIR);

$filelist = @filelist;
$i = 0;

for(;;){
        if(defined $filelist[$i]){ 
            print "$filelist[$i]\n";
        } else {
            exit;
        };
        $i++;
}

    [download]
[reply]
[d/l]

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