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

I need to print out an html list of all images that are contained in a certain directory. Any suggestions on the best way of doing so?

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Re: directory list
by Adam (Vicar) on Sep 20, 2000 at 03:23 UTC
    I know some people don't like glob, but I do. 
    my @images = map {glob} ( '*.gif', '*.jpg', '*.jpeg' );

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    Or you could glob the whole directory and then assume anythat was a file was an image... using -f as your check: 
    my @files = grep { -f } glob '*';
# warning! some elements in @files might not be images.

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Re: directory list
by merlyn (Sage) on Sep 20, 2000 at 05:07 UTC
    Hmm. Most people so far missed an important part of this list:
    I need to print out an html list of all images that are contained in a certain directory. Any suggestions on the best way of doing so?
    Which probably means you want to make a link for each, and you're doing it by running a CGI script of some kind. See my snippet "Show a clickable link list of images from a CGI script" for some code to do this.

    -- Randal L. Schwartz, Perl hacker

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      oh, an html list... 
      perl -e 'print "<html><body><pre>",`ls *jpg *png *gif`,"</pre></body><
+/html>"'

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      Ooops.
      Well I'm not sure how much help jmac needed in the html department: 
      use strict;
use CGI;
use CGI::Carp( 'fatalsToBrowser' );
use HTML::Entities;

my $q = CGI->new();

my $dir = '\images'; # or some other default.
chdir( $dir ) or die "Couldn't cd to '$dir', $!";

my @images = map {glob( "*.$_" )} qw( gif jpg jpeg tif xif bmp );
@images = map { encode_entities( $_ ) } @images;

print $q->header(), $q->start_html();
print $q->h1( "My Image files" );
print "\n<UL>\n";
print "<LI>${_}\n" for @images;
print "</UL>\n";
print $q->end_html();

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      UPDATE:
      Rather then argue further with merlyn, I removed the user input part of my code. That's what I get for trying to add a little functionality... sigh.
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        my $dir = $q->param('imageDir') ?  
          $q->param('imageDir') :  
          '\images'; # or some other default. 
 
die "Illegal directory name '$dir'" unless -d $dir; 
chdir( $dir ) or die "Couldn't cd to '$dir', $!";

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        I'm not sure I'd ever install a CGI script that took an unrestricted directory name from a parameter! Danger, Will Robinson!

        -- Randal L. Schwartz, Perl hacker

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Re: directory list
by arturo (Vicar) on Sep 20, 2000 at 03:25 UTC
    Use opendir and readdir (perldoc -f opendir and the same for readdir) 
    opendir HTMLDIR, $directory_name or die "Can't open $directory_name: $
+!\n";
while (readdir (HTMLDIR)) {
    push @images, $_) if /\.(png|jpg|gif|tiff)/;
}

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    When you're done, @images will contain a list of the files with the extensions jpg, png, gif, or tiff (go wild here =)
    UPDATE : d'oh! the loop I wrote above doesn't set $_ as it loops through the directory. Try 

    foreach ((readdir(HTMLDIR)) {
# stuff
}

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    instead.

    And, while we're at it, you could do 

    my @files = grep { /png|gif|jpg|tiff$/ } (readdir(DIR));

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    For one-liner goodness (grep { condition } list grabs everything in list that meets condition)
    I daresay these may not be as efficient as Adam's solution above.

    Philosophy can be made out of anything -- or less

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Re: directory list
by fundflow (Chaplain) on Sep 20, 2000 at 04:09 UTC
    Here are two short options:

    @images = glob('*.{tif,jpg,jpeg}');

or

@images = <*.{tif,jpg,jpeg}>;

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Re: directory list
by jmac (Initiate) on Sep 20, 2000 at 03:29 UTC
    thanks a bunch for the speedy replies!
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