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

Hello again! I built a page for my teacher that loads the contents of a file into a textarea in a form on a web page so he can edit some links from any browser. If the text file is empty, the script that displays the links jumps to a subroutine that says, "no links at this time"

This is only happening when I delete the contents of the file on the server. If I do it by clearing the contents of the textarea through a brower and pass them to the script, there is always 1 blank character.

I am still new to all of this, but am reading a book right now and trying things like chop, chomp, truncate.. ?

Am I close? Or have I gone completely mad?!

Here is the code that writes what was in the textarea to file: 

#!/usr/bin/perl

use CGI::Carp qw(fatalsToBrowser);
use strict;
use CGI ':standard';

my $list;
my @changes = param('tellmessage');

open(FILE, ">eetnlinks.txt") || die "Can't open file!";
  flock(FILE, 2) || die "Can't lock file!";
  #truncate(FILE,0);
    foreach $list (@changes) {
      chomp ($list);
      print FILE "$list\n";    
    }    
close(FILE);

[download]

Replies are listed 'Best First'.
Re: Always leaving one space in file
by zby (Vicar) on Apr 23, 2003 at 15:07 UTC
    From your description it seems that the tellmessage parameter is a textarea - but you use it as if it was a multiple choice scrolling list.

    And to answer your question - the my @changes = param('tellmessage'); sets the @changes list to a one element list (if the tellmessage parameter is empty than the list contains one empty string). Thus the foreach loop allways is executed once - and when the parameter is empty the print statement prints the "\n" character.

[reply]
[d/l]
[select]
      I tried this with no success:

      my $list;
my @changes = param('tellmessage');

######################

if (@changes eq " ") {
  exit
}

######################

open(FILE, ">eetnlinks.txt") || die "Can't open file!";
  flock(FILE, 2) || die "Can't lock file!";
  #truncate(FILE,0);
    foreach $list (@changes) {
      chomp ($list);
      print FILE "$list\n";    
    }    
close(FILE);

      [download]
      Or could I count the length of @changes and compare it: 
      if (@changes > 1) {
  exit;
}

      [download]
      If that would work, I don't know how to count the length of the string... ?
[reply]
[d/l]
[select]
        Try not opening the file unless you have data in the @changes array: 
        if (@changes) {
   # do stuff here
}

        [download]
        I don't know how to count the length of the string...?: 
        my $length = length $some_string;

        [download]
        -- vek --
[reply]
[d/l]
[select]
        Why do you insist on a list? Does the tellmesage parameter contain multiple values? If it was a textarea than it contains just one value and you can retrieve it with: 
        my $change = param('tellmessage');

        [download]
[reply]
[d/l]
[select]
        what I meant was: 
        if (@changes eq " ") {
  @changes eq ""}
}

        [download]
[reply]
[d/l]

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