aarestad has asked for the wisdom of the Perl Monks concerning the following question:

So I wrote a Perl script about 5 months ago to parse a rather strange text file. Here's a sample of the source file: 
AACE_1:
{
 class: mic_if_win,
 label: "!AACE.*",
 mic_if_handles_windows: 1
}
{
 rtree_state: close,
 ltree_state: close
}
AACE_1."ADDR LINE1":
{
 class: field,
 id: 734
}

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etc. (For those who may recognize it, it's a GUI Map file used by WinRunner, an automated testing suite.) Each header of a braced chunk is either a screen (green-scren) name or field name - the field names have the screen name they're on, followed by ".", followed by the field name. To determine whether I'm on a line that contains a screen name, I use this line: 
if ($desc != 0 and /^([^.]+):$/) {
    # do stuff
}

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Looking at that regex now, I think, it'd be smarter to use 
/^(\w+):$/

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but that's not the issue. Both the original regex and the one I have above produce this warning for each and every line of input: 
Use of uninitialized value in concatenation (.) or string at ./genguim
+apdoc.pl line 52, <GUIFILE> line n.

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WTF? This script worked perfectly 5 months ago. The input file has not changed, nor has the script. Is there something fundamentally wrong with the regex?

Replies are listed 'Best First'.
Re: Code rot?
by dragonchild (Archbishop) on Sep 22, 2003 at 19:52 UTC
    You upgraded from Perl 5.00x to Perl 5.6.x or 5.8.x, right?

    ------
    We are the carpenters and bricklayers of the Information Age.

    The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

    Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

[reply]
      You betcha - I'm currently using 5.8.0 for the latest Cygwin (1.5.5-cr-0x9b), and back then I was using, if not 5.8.0, then 5.6.1, also for Cygwin.
[reply]
        Hence, something changed. You need to tell us these things!

        There is no code that is guaranteed to work between Perl versions. You may have to tweak it a little. I would suggest using perl -MO=Deparse scriptname.pl to find out what it's doing. The problem isn't in the if-condition. It's earlier on, where $_ is set.

        ------
        We are the carpenters and bricklayers of the Information Age.

        The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

        Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

[reply]
[d/l]

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