[Perl] Strange ne "NO" behavior.

Shell Programming and Scripting
1

Hi there,

I have a strange problem and I cannot figure it out what I am doing wrong here.
Let me try to picture it.
In principle it is prety straight forward, but something odd is happening.

Here is part of the input file snmp_alm.cfg:

##############################################################
# Specifies if the PURGE Notification should be sent or Not  #
# Yes means the PURGE Notification is Not sent (disabled)    #
# No viceversa                                               #
# Default Value is: NO                                       #
##############################################################

DISABLE_PURGE_NOTIF:           	YES

Here is part of the Perl code:

my $disable_purge_notif;
my $disable_purge_notif_value;

open (SNMP_ALM_CFG, $snmp_alm_cfg) or die "Cannot open $snmp_alm_cfg";
while (<SNMP_ALM_CFG>) {
  s/#.*//;            # ignore comments by erasing them
  next if /^(\s)*$/;  # skip blank lines
  s/^[\s\t]+//;       # remove leading tabs and spaces
  s/[\s\t]+$//;       # remove trailing tabs and spaces
  s/://;              # remove :
  chomp;
	
  @_=split(/[\s\t]+/, $_, 2); # split on tabs on spaces

if (/DISABLE_PURGE_NOTIF/) {
  $disable_purge_notif = $_[0];
  $disable_purge_notif_value = $_[1];
  printf "Found parameter    : $disable_purge_notif\n";
  printf "Current setting is : $disable_purge_notif_value\n";
  if ( $disable_ack_notif_value ne "NO" ) {
    printf "ERROR - Correct $disable_purge_notif setting is : NO\n";
  }
}  
}
close (SNMP_ALM_CFG);

This is the output when the parameter value is YES:

Found parameter    : DISABLE_PURGE_NOTIF
Current setting is : YES
ERROR - Correct DISABLE_PURGE_NOTIF setting is : NO

So far so good.
But now I set it to NO:

DISABLE_PURGE_NOTIF:           	NO

Now I get the following output:

Found parameter    : DISABLE_PURGE_NOTIF
Current setting is : NO
ERROR - Correct DISABLE_PURGE_NOTIF setting is : NO

I thought "NO" ne "NO" would give 0 or false.
Using the debugger I see that $disable_ack_notif_value is indeed 'NO', so I am confused here.

Anything I overlooked ?

2

Might be that I'm overlooking something or that it's not part of the posted code, but where do you set $disable_ack_notif_value? I only see $disable_purge_notif and $disable_purge_notif_value.

3

:b:

Stupid me. I already thought it had to be something like this. It made me crazy :slight_smile:

This works:

if ( $disable_purge_notif_value ne "NO" ) {

Thanks !!