Tie::File and CGI

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

Hello monks just another question for you about Tie::File.
I'm writing a program for a flat database and i made a little module.
It includes Tie::File module.
The program works well if it is a command line executable but it fails if it is a CGI because it can't tie my file and the $Card reference doesn't contain anything...
Any ideas?
the code in CGI

use CGI;
use Gnome::Card;
my $q = new CGI;
print   $q -> header("text/html"),
        $q -> start_html(-'title'=>"Example",),
        $q -> h1("Programma di gestione remota GnomeCard");

my $filecard="../GnomeCard.gcrd";

my $Card=Leggi($filecard);

print "$Card->[2] is good.. \n";
print   $q -> end_html();
[download]

the code in module Gnome::Card

sub Leggi{
    my @Card;
    my $filecard=shift;

    tie @Card, 'Tie::File', $filecard;

    ...

    return \@Card;
}
[download]

PS: GnomeCard is the module that i wrote
PS: The module is propely installed
PS: i've the privileges in reading file and if i put this code in CGI it prints all rows:

open FILE, "<$filecard";
while(<FILE>) {print $_,"<br>";}
[download]

---
os: Linux Mandrake 9.0

Comment on Tie::File and CGI Select or Download Code

Replies are listed 'Best First'.
Re: Tie::File and CGI by shemp (Deacon) on Aug 04, 2003 at 17:36 UTC
It looks like a path issue to me. When you run the script from the command line, your cwd for the program is different from when you run from the CGI. The line: `my $filecard="../GnomeCard.gcrd";` [download] is very suspect because it includes a relative path. If you add to your script a die statement if the tie fails, that may help you catch the error, such as: `tie @Card, 'Tie::File', $filecard or die "couldnt tie $filecard as a Tie::File $!\n";` [download] This way, the reason the tie didnt work will be sitting in your error log. Its generally important to keep in mind that cgi scripts will run under a different environment when run as a cgi, as opposed to running from the command line. Unless you have a very specific reason, commands like tie() or open() should always have failure tests - it will save you many headaches in the future. Not directly related to the question, but you open statement should also have error checking: `open FILE, "<$filecard" or die "couildnt open $filecard for reading $!\n";` [download]	[reply] [d/l] [select]
Re: Tie::File and CGI by RMGir (Prior) on Aug 04, 2003 at 17:36 UTC
This is just a guess, but you're specifying "$filecard" to be a relative path, "../GnomeCard.gcrd". Is it possible the current working directory isn't what you expect when you're running as a CGI? Try putting an absolute path in for $filecard, or doing an explicit "chdir" early in the script to where you expect to be. -- Mike	[reply]