Perl String comparison

Xris718 · 04-01-2005, 11:20 AM

Hi

I need to know how to do string comparisons in perl just like shell does. How do you convert the following into perl?
ie:

if [-n "$string"]; then
statement.....

if [-z "$string"]; then
statement...

if [$var -gt 0]; then
statement...

dillybat · 04-01-2005, 12:04 PM

Quote:

Originally posted by Xris718
Hi

I need to know how to do string comparisons in perl just like shell does. How do you convert the following into perl?
ie:

if [-n "$string"]; then
statement.....

if [-z "$string"]; then
statement...

if [$var -gt 0]; then
statement...

use to see if a string is empty or not
if ($string) { # string contains something
statement...
}

if (! $sting) { # string is emtpy
statement...
}

if ($var > 0 ) { #if variable is greater than 0, assuming is not a string
statement...
}

dillybat · 04-01-2005, 12:09 PM

THE SCRIPT
#!/usr/bin/perl

my $string = "good-by";
my $twine = undef;
my $rope = "hello";

if ($string) {
print "string present\n";
}

if (! $twine) {
print "twine NOT present\n";
}

if ($string gt $rope) {
print "string bigger\n";
}
elsif ($rope gt $string) {
print "rope bigger\n";
}

THE OUTPUT:
string present
twine NOT present
rope bigger

Xris718 · 04-01-2005, 12:41 PM

Thanks guys

Xris718 · 04-01-2005, 12:52 PM

oh what about this convert into perl?
ie:

if [! -z $string]; then
something....

dillybat · 04-01-2005, 01:59 PM

Quote:

Originally posted by Xris718
oh what about this convert into perl?
ie:

if [! -z $string]; then
something....

I'm not to good at shell scripting but I believe that reads "if not zero length". If I am reading that right then look at my second posting with the script for an example... What you want is

Code:

if ($string)

.