Perl noob tries to translate a scipt to PHP - need some help

[Paulchen]

Hello, I have found a perl script and need to "translate" this to PHP. I try to do it step by step and the first part of it is this function (the whole script is found at http://nonsense.sourceforge.net/):

### Load and parse a datafile, slurping the contents into the %pool hash
sub LoadDataFile { 
   my $file = shift;
   $file = SafeFile( $file ) if $cgi_mode;
   open IN, $file or die "Error opening $file... $!\n";
   local $/ = '';
 
   SECTION: while( <IN> ) { 
      my( @temp ) = split /\n/, $_;
      my $key = shift @temp;
      $pool{$key} = [ @temp ];
   }
   close IN;
}

$_ seems to hold the actual lines one after another during the while loop.

my( @temp ) = split /\n/, $_;

Why is $_ splitted by \n here? $_ should only contain one line from the input file already, right?

my $key = shift @temp;

Okay, $key is now the current element of the @temp array. But since @temp should only contain the current line from the input file, $key should be equal to the current line from the input file. (?!)

$pool{$key} = [ @temp ];

This one I don't understand at all. Which value is given the elemt of $pool with the key $key here? What does an array like @temp in [] mean? I thought [] normally contains the key for an element of an array like $pool[$key]...

What would helpme is a way to look at the contents of $pool after the while loop is done, but I don't know how to do that in perl. print $pool; doesn't work.

While this function works fine in the whole scipt, I tried to put it in a separate file to examine how it works. So my whole file would be

#!/usr/bin/perl
 
use strict;
use CGI;
my $q = new CGI;
open(INFILE,  "test.data")   or die "Can't open input.txt: $!";
 
# print header and start the markup output
 
print $q->header( "text/html" ),$q->start_html( "hello from perl cgi!" );
 
while (<INFILE>) {     # assigns each line in turn to $_ 
    print $q->p("Just read in this line: $_");
    my( @temp ) = split /\n/, $_;
    print $q->strong("temp = @temp<br />");
    my $key = shift @temp;
    print $q->strong("key = $key<br />");
    #$pool{$key} = [ @temp ];
}
print $q->end_html;

But as soon as I uncomment the line with $pool, I get an Internal Server Error. Why is this not working in a standalone script?

I hope anybody roughly understands what I mean and what I'd like to know. I know my english is bad and so it's very hard to write about a script language that I don't understand either ;-)

[eWish]

Welcome to TSDN!

Add the following lines to your script.

use warnings;
use CGI::Carp qw/fatalsToBrowser/; #For Debugging Only

One error you will get is caused by the fact that you have not delcared the hash $pool{$key} you are trying to use.

my %pool;

This page is a great resource when you get error like this. Helpful in tracking down some of the standard problems.

[numberwhun]

Welcome to TSDN!

Add the following lines to your script.

use warnings;
use CGI::Carp qw/fatalsToBrowser/; #For Debugging Only

One error you will get is caused by the fact that you have not delcared the hash $pool{$key} you are trying to use.

my %pool;

This page is a great resource when you get error like this. Helpful in tracking down some of the standard problems.

He he he, isn't PHP right up your alley?

Regards,

Jeff

[eWish]

He he he, isn't PHP right up your alley?

Regards,

Jeff

Yes...that is why I handle all of the PHP related questions.

[Paulchen]

Thank you, that helped.

In php I can output the elements of an array with the print_r function. Is there an equivalent in perl to do this? I'd like to output the elements of $pool{$key}, but if I use print I only get something like that:

@pool{$key} = ARRAY(0x822dae4)

What part of the @temp arry is

$pool{$key} = [ @temp ];

assigning to $pool{$key}? I wonder what an array in these braces [ ] mean...

[eWish]

my @array = (qw(Hello Every One));
print @array; # print entire array
print $array[0]; #print the first element of the array
 
 
$pool{$key} # is a hash element.

[numberwhun]

Thank you, that helped.

In php I can output the elements of an array with the print_r function. Is there an equivalent in perl to do this? I'd like to output the elements of $pool{$key}, but if I use print I only get something like that:

@pool{$key} = ARRAY(0x822dae4)

What part of the @temp arry is

$pool{$key} = [ @temp ];

assigning to $pool{$key}? I wonder what an array in these braces [ ] mean...

When accessing an array in Perl, the array is called @array, but when accessing a specific element, it is accessed like "$array[0]", where the element number, starting at zero, is in square brackets.

The curly braces { and } are used when accessing hashes, not arrays

I suggest you find a good book that will show you the basics and go from there.

Regards,

Jeff