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

Monks, I need to be able to check if a file exists on the server. The filename is in the database, but may not be on the server. I know how to check the database for the file, but I'm unsure how to verify that the filename is on the server. 
$pointer2 = $sth2->fetchrow_hashref;
$image = $pointer2->{'image'};
if ($image) {
How do I verify it exists?
}

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Thanks.

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Re: Check if image file exists
by BrowserUk (Patriarch) on Apr 07, 2012 at 23:42 UTC

    Assuming that $image contains the absolute path to the file:

    $pointer2 = $sth2->fetchrow_hashref;
$image = $pointer2->{'image'};
if ($image && -f $image ) {
    ## it exists
}
else {
    ## It doesn't (or the DB query return false)
}

    [download]
    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.

    The start of some sanity?
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[d/l]
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      I think I spoke too soon, or I'm doing something wrong. The following doesn't work. It returns all noavatar50.png. 
      $picture="/$username/$picture";

        if ($picture && -f $picture ) {
          
        $thumb30 = "<img src=\"$picture\" width=30 height=30 border=0>
+";
        } else {
            $thumb30 = "<img src=\"/images/noavatar50.png\" width=30 h
+eight=30 border=0>";
        
        }

      [download]
      Ideally I'd like to use something like this for the first IF statement, but it doesn't work. 
      if (($picture) && ($scope ne "Private") && (-f $picture)) {

      [download]
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        Perl's file-test operators only care about the file's location on your server. If the file's URI is /username/picture.jpg, that's almost certainly not the file's full pathname on your system. That might be something like /var/www/images/username/picture.jpg, or something entirely different. You'll have to prepend $picture with the filesystem location of your picture subdirectory. Also, use a different quoting method to get rid of those backslashed quotes: 

        $picture = "/$username/$picture";
my $picture_path = "/var/www/images$picture"; # or whatever
if( -f $picture_path ){
  $thumb30 = qq| <img src="$picture" /> |;
} else {
  $thumb30 = qq| <img src="/images/noavatar50.png" /> |;
}

        [download]

        Aaron B.
        My Woefully Neglected Blog, where I occasionally mention Perl.

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[d/l]
      Perfect. Thanks!
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Re: Check if image file exists
by mendeepak (Scribe) on Apr 10, 2012 at 05:57 UTC

    what have you stored in your database a complete sever path like /var/www/project/images/1.jpg or a complete browser path like http://www.yoursite.com/image/1.jpg if its the second one try to get the complete server path and check using if (-e $filename) { print "File Exists!"; }

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