Shell Programming and Scripting

Hi

By using select clause I'm trying to pull out the rows to a variable.
If the variable has 0 row(s) selected then i'm printing some text message
else printing some other text message

Code:

if($xyz =~ m/0 row/)
{ 
  print "0 rows ";
}
else
{ 
  print " There are rows";
}

By my problem is if the variable has 20 row(s) in it ..it is printing as 0 rows as it's matching 0 in it...

I need to match the exact word '0 row'

Can anyone help me please?

What is the value of $xyz ?

If it's simply "20 row(s)" or "0 row(s)", you could use:

Code:

/^0 row/

If it's something like "Found 20 row(s)" or "Found 0 row(s)" following should work:

Code:

/ 0 row/

Thanks for the reply..

The value of the variable keeps changing say 0 row(s) selected,21 row(s) selected,10 row(s) selected,,20 row(s) selected etc...
I want to print "0 rows" when there are 0 rows in the variable
other wise the no of rows in the variable.

You're welcome.
In that case you can safely use m/^0 row/, it matches if the variable starts with 0 row.

The Best way in Perl to get an exactly exact match is to use the eq operator ( for strings ) or the == operator ( for numbers ), not a regex.

Code:

if  ( $xyz eq '0 rows' ) { .... }

If you need the flexibility the regex, this idiom is more precise:

Code:

if ( $xyz =~ /^\b0 rows\b/ ) { ... }  else { .... }

the "\b" 's ( zero-width boundary match ) which surround the string make sure that it will not match overlapping or embedded things.

Consider this:

Code:

use strict;
use warnings;

$_ = 'contentious';
print "HIT, NO BOUNDARY\n" if /tent/;
print "HIT, WITH BOUNDARY\n" if /\btent\b/;

For me this outputs:

Code:

HIT, NO BOUNDARY

Hope that Helps.