Found this in perldoc Getopt::Long. Doesn't seem to be backed up by what you've found tho'.

Return values and Errors

Configuration errors and errors in the option definitions are signalled using die() and will terminate the calling program unless the call to Getopt::Long::GetOptions() was embedded in eval { ... } or die() was trapped using $SIG{__DIE__}.

A return value of 1 (true) indicates success.

A return status of 0 (false) indicates that the function detected one or more errors during option parsing. These errors are signalled using warn() and can be trapped with $SIG{__WARN__}.

Errors that can't happen are signalled using Carp::croak().

Perl Training in the UK <http://www.iterative-software.com>

My documentation says (Getopt::Long, version 2.25):

GetOptions() will return a true value if the command line could be processed successfully. Otherwise, it will write error messages to STDERR, and return a false result.

Give your code with some examples then we can try to figure out what went wrong ...

-- Hofmator

This seems not to be the case. Tried to do so to achieve a "multiple GetOptions behaviour" see here.

Bye
 PetaMem     All Perl:   MT, NLP, NLU

Here's what's happening: by default, the permute option is set to true (unless your environment variable POSIXLY_CORRECT is set). That means that option values may be mixed with non-option values (like, say, filenames). With this (default) behavior, your -h 1 -c 2 is the same as saying -h -c 2 1. In other words, if you look at @ARGV, you'll see the extra '1' argument.

To turn this default behavior off, just do this:

Getopt::Long::Configure('nopermute');
[download]

I have the "Programming with perl-Modules" from Patwardhan and Irving (year 1997) where this information is not present...

#!/usr/bin/perl -w
 
use strict;
use Getopt::Long;
 
# If it comes to parallelizing, How many processes do we allow to star
+t
# default is amount of CPUs on that system. May be overridden by comma
+ndline
my $cpu = &num_cpus;
 
my $goback = GetOptions('cpu=i', \$cpu,
           'c=i',   \$cpu,
           'help',  \&cmdline_usage,
           'h',     \&cmdline_usage);
 
print "Number of CPUs here: $cpu\n";
print "Goback was: $goback\n";
 
 
# {{{ get the number of CPUs on that system
#     returns: number of CPUs or 1 if no /proc/cpuinfo was found
sub num_cpus {
    my $num_cpus = 0;
    my $infofile = '/proc/cpuinfo';
 
    if($^O eq 'linux') {         # Yes this is Linux we're running on
        if(-e $infofile) {       # and cpuinfo exists
            open FILE, $infofile;
            while(<FILE>) {
                $num_cpus++ if(/processor/);
            }
            close FILE;
        }
    } # elsif ... your favourite OS detection routine here
 
    # If this is not a known OS we're running on ($num_cpus is then 0)
    # so better be careful and assume 1 CPU
    return $num_cpus || 1;
}
# }}}
[download]

rj@proxima:~ > pxp.pl -cpu 1
Number of CPUs here: 1
Goback was: 1

=> Ok

rj@proxima:~ > pxp.pl -cpu
Option cpu requires an argument
Number of CPUs here: 2
Goback was:

=> Ok

rj@proxima:~ > pxp.pl -cpu 1 -h=1
Option h does not take an argument
Number of CPUs here: 1
Goback was:

=> Ok

rj@proxima:~ > pxp.pl -cpu 1 -h 1
Usage:
 
-c, --cpu        set the number of CPUs (define parallelization)
-h, --help       print this usage information
Number of CPUs here: 1
Goback was: 1

=> IMHO not Ok

Update: The last case definitedly is not ok according to 1211. Iīm citing:

If the option specifier is ``one:i'' (i.e. takes an optional integer argument), then the
  following situations are handled: 

     -one -two            -> $opt_one = '', -two is next option
     -one -2              -> $opt_one = -2

What is the output when you call Getopt::Long::Configure('debug') ?

update: fixed spelling on Configure

Here it is:

rj@proxima:~/proj/elric/src > pxp.pl
GetOpt::Long 2.23 called from package "main".
  GetOptionsAl $Revision: 2.27 $
  ARGV: ()
  autoabbrev=1,bundling=0,getopt_compat=1,order=1,
  ignorecase=1,passthrough=0,genprefix="(--|-|\+)".
=> link "cpu" to SCALAR(0x8142340)
=> link "c" to SCALAR(0x8142340)
=> link "help" to CODE(0x814258c)
=> link "h" to CODE(0x814258c)
=> $opctl{"cpu"} = "=i"
   $opctl{"h"} = ""
   $opctl{"help"} = ""
   $opctl{"c"} = "=i"
[download]

Why not? How else would you get a File named "1" into your script?

I don't see what's wrong here (in the -cpu 1 -h 1 case).

If you look at @ARGV after the GetOptions call, it should contain the argument 1.

As the AM said, how does anyone know that the 1 is a mistaken argument? It looks like a file name to me (and to GetOptions)... what happens if you say -h 1 -cpu 1? It should complain.

It doesnīt:

rj@satyr: pxp.pl -h 1 -cpu 1
Usage: elric [option]
 
-c, --cpu        set the number of CPUs (define parallelization)
-h, --help       print this usage information
Number of CPUs here: 1
Goback was: 1
[download]

Bug here?

Ciao