Re: Question about reading specific line in a text file

[Marshall]

Here is some example regex code to get you started on the part about getting what you want from the line.

Perl Regular expressions have some cool shortcut symbols. Below we have "w" which means a word character (A-Z,a-z_0-9), W means not a word character, s is a whitespace character (\s\t\r\n\f), S is not one.

The regex means: start at beginning of line, skip any non-word characters if they are there (skips the " ), match a series of word characters followed by one or more spaces, then a field of non-space characters. w doesn't work here because of the "-", so easy was just to say non-whitespace. There are lots of variations on this theme. However you will go far with w,W,s,S and understanding what * and + mean.

Note that if the match fails, the result is undef.

#!/usr/bin/perl -w
use strict;

my $text = '"SECTIONS 1-2-3-4 Offered Every Performance!"';

#one way use regex match...

$text =~ m/^\W*(\w+\s+\S+)/; #note doesn't modify $text
                             #just checks for match
my $x = $1;
print "$x\n";

# another way without using $1
# match is in array context and we use list slice to get
# the $1 match data

$x = ($text =~ m/^\W*(\w+\s+\S+)/)[0];
print "$x\n";

__END__
prints .....
SECTIONS 1-2-3-4
SECTIONS 1-2-3-4

Oh, I wouldn't worry about reading whole file at once unless it is truly huge. This is obviously some very specialized file with special meaning to line 76. Use judgment on how big your files are gonna be. If its gonna be huge then the ideas to just read til line 76 are worthwhile. Just saying that often the simple approach is just fine for lots of tasks..added complexity has its own cost: Your time!