What does this perl crash means? - perl

Question

Can someone tell me what this means?
if (not defined $config{'crontab'}) {
die "no crontab defined!";
}
I want to open a file crontab.txt but the perl script crashes at this line and I don't really know any perl.
EDIT 1
It goes like this:
sub main()
{
my %config = %{getCommandLineOptions()};
my $programdir = File::Spec->canonpath ( (fileparse ( Win32::GetFullPathName($PROGRAM_NAME) ))[1] );
my $logdir = File::Spec->catdir ($programdir, 'logs');
$logfile = File::Spec->catfile ($logdir, 'cronw.log');
configureLogger($logfile);
$log = get_logger("cronw::cronService-pl");
# if --exec option supplied, we are being invoked to execute a job
if ($config{exec}) {
execJob(decodeArgs($config{exec}), decodeArgs($config{args}));
return;
}
my $cronfile = $config{'crontab'};
$log->info('starting service');
$log->debug('programdir: '.$programdir);
$log->debug('logfile: '.$logfile);
if (not defined $config{'crontab'}) {
$log->error("no crontab defined!\n");
die "no crontab defined!";
# fixme: crontab detection?
}
$log->debug('crontab: '.$config{'crontab'});
And I'm trying to load this 'crontab.txt' file...
sub getCommandLineOptions()
{
my $clParser = new Getopt::Long::Parser config => ["gnu_getopt", "pass_through"];
my %config = ();
my #parameter = ( 'crontab|cronfile=s',
'exec=s',
'args=s',
'v|verbose'
);
$clParser->getoptions (\%config, #parameter);
if (scalar (#ARGV) != 0) { $config{'unknownParameter'} = $true; }
return \%config;
}
Probably I have to give the script an argument

Answer 1

Probably I have to give the script an argument
I would say so.
$ script --cronfile=somefile

Answer 2

That code looks to see whether there is a key 'crontab' in the hash %config. If not, then it calls die and terminates.
If that's not what you expect to happen, then somewhere else in your script there should be something that is setting $config{'crontab'}, but there is not currently enough information in your question to determine what that might be.

Answer 3

Probably the file path of crontab.txt is expected in %config hash, pointed by the 'crontab' key, but isn't there! If so, a DIRTY solution CAN BE:
$config{'crontab'}='FULLPATH/crontab.txt';
#if (not defined $config{'crontab'}) {
# die "no crontab defined!";
#}
but this may not work because there is something like $config{'prefix'} and what you will try to open is the path represented by the concatenation of both, or just because in $config{'crontab'} is expected any other value than full path!