In Perl most simple string comarison operations you could think of are done using the string comparison operators or the regex match operator.

But you say you have a genuine problem. And if it could be trivially solved using the string comparison operators or the regex match operator it would not be a genuine problem.

Perhaps you should try describing your problem.

#comparison.pl
use warnings;
use strict;

if ("1a" lt "2b") {
  print "1a is less than 2b.";
}

if ("2b" gt "1a") {
  print "2b is greater than 1a.";
}
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    if($temp_var1 == $temp_var2 and $temp_var2 == $temp_var3)
        {printf LOG"1";}
        if($temp_var2 != $temp_var1 and $temp_var3 == $temp_var2)
        {printf LOG"2";}
        if($temp_var2 eq $null and $temp_var3 eq $null)               
+ 
        {printf LOG"3";}
        if($temp_var3 == $temp_var1 and $temp_var2 eq $null)
        {printf LOG"4";}
        if($temp_var1 != $temp_var2 and $temp_var3 eq $null)
        {printf LOG"6";}
        if($temp_var2 != $temp_var1 and $temp_var3 != $temp_var1)
        {printf LOG"5";}
        if($temp_var1 == $temp_var2 and $temp_var3 != $temp_var1)
        {printf LOG"5";}
        if($temp_var2 == $temp_var1 and $temp_var3 eq $null)
        {printf LOG"5";}
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There is no clue there as to what you are trying to achieve.

I have 3 variables,I want to compare those 3 based on a particular logic

All i want now is the variables are alpha numeric, i tried regex but i am unable to achieve the above

Hope i get a guiding light.
Prad

Alpha: 
if ( $temp_var1 gt $tempvar2 ) { print "gt\n"; }
Numerically: 
  $_ = $temp_var1;
  tr/a-zA-Z//g;
  $tnum1 = $_;
  $_ = $temp_var2;
  tr/a-zA-Z//g;
  $tnum2 = $_;
if ( $tnum1 > $tnum2 ) { print "gt\n"; }
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