How to write to a file using CGI

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

I am using CGI-Application using Apache on Windows XP. I have a run mode setup so that I can open a page, slurp in a template into a textarea on a form, and then it's supposed to write the current info in the textarea to a file when the submit button is pushed. Here is the form field code:

<form name="mainform" action="webapp.cgi?rm=mode9" method="post">
<textarea name="text_field" cols="60" rows="20"><TMPL_INCLUDE NAME="me
+nu.tmpl"></textarea>
<br>
<button type="submit">Update</button>&nbsp;&nbsp;&nbsp;&nbsp;<button t
+ype="reset">Reset Form</button>
</form>
[download]

here is the code for the save:

sub save_form {
    my $self = shift;

    # Get CGI query object
    my $q = $self->query();
    my $record = $q->param( 'text_field' );

    open( FH, '>output.txt' ) || die "Can't open output.txt: $!";
    print FH $record;
    close ( FH );

    # go back to the beginning
    return $self->run_mode( 'mode1' );
}
[download]

I know my cgi-app is working because I can navigate to other pages in different run modes. Please help! I see wisdom! Bob

Comment on How to write to a file using CGI Select or Download Code

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Re: How to write to a file using CGI by chromatic (Archbishop) on Jun 29, 2003 at 22:54 UTC
There are two possibilities. First, it's possible that you might not get any data from the form field. That's unlikely as you're testing things, but it's a possibility. Second and likely the case, you don't have permission to open the file. You're checking the return value of open which is good. Now, check it. Look in the error log or use CGI::Carp to send the error to the browser during debugging. That'll give you a clue as to what the problem is — probably no permission to write to the current directory.	[reply]
Re: How to write to a file using CGI by Zaxo (Archbishop) on Jun 30, 2003 at 00:56 UTC
You are overwriting each query with the next by using a fixed file name and opening '>'. CGI has a save() method which takes a filehandle and saves the form data in a format that CGI.pm can reload from. `sub save_form { my $self = shift; my $q = $self->query(); #lexical fh, name is argument open my $fh, '>', shift \|\| '/path/to/output.txt' or die $!; $q->save($fh); $self->run_mode('model'); }` [download] The use of a relative file name may be the cause of your trouble. What is the current directory when the cgi runs? Do you have permissions to write there when run by the Apache cgi_script handler? After Compline, Zaxo	[reply] [d/l]
Re: How to write to a file using CGI by fglock (Vicar) on Jun 29, 2003 at 21:57 UTC
Maybe this helps you with debugging: `print "Writing record ... "; print FH "record is [$record]\n"; print "Wrote record: [$record]";` [download]	[reply] [d/l]