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From: pem@frankland-river.aaii.oz.au (pem)
Newsgroups: comp.lang.perl
Subject: Weird grep bug ? (perl 3.0 pl8)
Message-ID: <845@frankland-river.aaii.oz.au>
Date: 19 Jan 90 04:01:29 GMT
Organization: Australian AI Institute
Lines: 46

I have noticed what seems to be a strange bug in grep.
I am not quite sure what is going on -- the problem seems only to
occur when I use a 'do <file>' statement to include a header.

I was wondering if anyone else has seen this something like this before.

Here is a small program which demonstrates the problem on my machine:
(a sun 3/60 running perl 3.0 pl8)

All it does is use the built in grep command to match at the start of
an array of lines, returning a new array of matching lines.
If I include 'getopts.pl', for example, the grep (wrongly) matches
every line.  Otherwise it works as I would have expected.

-----------cut here-----------
#!/usr/bin/perl

# comment the next line and the program behaves fine!
do 'getopts.pl';

$" = "\n";

@dump_lines = ( 
    "f:/, 0", "f:/usr, 1",
    "h:/, 3", "h:/usr, 4",
    "f:/, 5", "f:/usr, 6",
    "h:/, 7", "h:/usr, 8"
    );

for (;;) {
    print "\n(note: if you type 'f' you would expect to get only 4 matching lines)\n";
    print "Which dump ? (name eg. 'f' or '?' or 'q' to quit) ";
    chop($_ = <STDIN>);
    if (/^[Qq]$/)	{exit 0;}
    elsif (/^\?$/)	{print("@dump_lines"); next;}
    /^\s*(\S+)/;
    @entry = grep(/^$1/, @dump_lines);
    print "found the following entries in the log:\n@entry\n";
}

------------------
Paul E. Maisano
Australian Artificial Intelligence Institute
1 Grattan St. Carlton, Vic. 3053, Australia
Ph: +613 663-7922  Fax: +613 663-7937
Email: pem@aaii.oz.au