in reply to Empty string checking in output

if(@output ne '')
That will always evaluate to true since an array evaluated in scalar context returns the number of elements (0, 1, 2, etc.); it will not return the empty string. Perhaps this will be better: 
if(@output)

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Re^2: Empty string checking in output
by Kumar Mantri (Novice) on Aug 17, 2011 at 05:02 UTC

    tulic , i tried that but the else block is not executing. i can explain the behavior of the cisco device if a particular command is not present... if i telnet into cisco device it will show as 

    2960#

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    here at this prompt i want to check one command i.e 
    2960#sh run | in ntp

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    if the configuration is not present then it will show as same 
    2960#

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    so at this time the in array @output doesn't contain anything but i dont know why the else block is not executing

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[d/l]
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      ... the in array @output doesn't contain anything but ... the else block is not executing ...

      ... because, contrary to what you think, the  @output array contains something. Try printing/dumping the contents of the array. Also, what code are you actually running? 

      >perl -wMstrict -le
"my @output = ();
 ;;
 if (@output) {
   print qq{true clause: array not empty};
   }
 else {
   print qq{false clause: array empty};
   }
"
false clause: array empty

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[d/l]
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        yes,i executed the block of code above its printing "true clause: array not empty" but how to find exactly what is there in that?i wrote dis code to check a configuration in cisco devices.

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