in reply to Scope Issue

If you're using Perl 5.10 or greater, you can also use the defined or operator:

my $f1missing = $t->waitfor(String => 'That file is unavailable', errmode => 'return') // 0;

What the code above does is similar to what Corion suggested. It tests whether the result is defined, and will substitute with 0 if it is not.

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Re^2: Scope Issue
by fidesachates (Monk) on Mar 15, 2011 at 13:12 UTC
    Am I wrong or did you mean || instead of //?
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      // is the defined or operator. || is the or operator. // and //= were added in in 5.10 as a shortcut for something along the lines of $var = defined $var ? $var : $default_value;

      $var //= $default_value; is much prettier IMHO. I'm fairly certain // and || short-circuit in the same exact way. It's easy enough to test.
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        I tried || and // and they both worked. Thanks to everyone for your contribution!

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      || is the regular or operator ("true, or ..." you might say).

      // is the defined or operator ("defined, or ...").

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        ah. good deal.
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Re^2: Scope Issue
by MKJ747 (Acolyte) on Mar 15, 2011 at 13:46 UTC

    Thanks, AR. That worked - the warning went away.

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      I have another question on this topic. I'm also getting a similar warning in another part of the code: "Use of uninitialized value $\ in concatenation (.) or string at C:\scripts\DailyComp2.8.pl line 208 (#1)". This warning comes from the following line of code:

      my $match_live = "\/LIVE>.*$\/";

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      I am defining a pattern match for Net::Telnet to use in various places in the code. The back slash in $\ is there to escape the forward slash which is the end of the pattern match, but it looks like PERL is interpreting it as variable. Any suggestions? Thanks

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        If you are constructing regular expressions, the qr operator is much more convenient:

        my $match_live = qr/LIVE>.*$/;

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        If Net::Telnet does not want qr-quoted regular expressions, use single quotes to construct your string and not interpolate variables:

        my $match_live = q'/LIVE>.*$/';

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