On Jul 9, saliminl said:
>Hi. This is my first post. I'm trying to write a script that retrieves
>data from a text file. The text files have several hundred instances of
>the string "EAMBER (non-constraint) = #" where the # is a number that
>can be negative and the last spacing after the equals sign is variable.
>My problem is in the loop; my expression matches ok, but it skips every
>other instance of the expression (leaving me with half my data). I
>added the counting variable as a debug to see what was going on, and in
>files with 600 instances of the string, it ends up at 300. Thanks a
>lot.
That's because you're doing:
while (<FH>) {
$line = <FH>;
# ...
}
The <FH> in the while condition ALREADY stores a line into $_, so you can
use that variable.
Also, your regex leaves a bit to be desired, and you might want to use
push() to add to your array, rather than explicitly indexing it.
#!/usr/bin/perl -w
use strict;
print "Input file name: \n";
chomp (my $input = <STDIN>);
open INPUT, "< $input" or die "can't read $input: $!";
open OUTPUT, "> sum.EAMBER" or die "can't write to sum.EAMBER: $!";
while (<INPUT>) {
if (/EAMBER\s\(non-constraint\)\s=\s+(-?\d*\.?\d*)/) {
push @EAMBER, $1;
print OUTPUT @EAMBER - 1, " $1\n";
}
}
close OUTPUT;
close INPUT;
In fact, you don't even need an array, unless you're doing something with
the values later. Just have a counter of some sort.
Note that my regex could match NOTHING in $1. To fix this, you can do:
if (/EAMBER\s\(non-constraint\)\s=\s+(-?(?=\.?\d)\d*\.?\d*)/) {
The addition of (?=\.?\d) means "look ahead to make sure we'll match an
optional . followed by a digit". That ensures that the \d*\.?\d* WILL
actually match something (since \d*\.?\d* can match 0 characters).
--
Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/
I am Marillion, the wielder of Ringril, known as Hesinaur, the Winter-Sun.
Are you a Monk? http://www.perlmonks.com/ http://forums.perlguru.com/
Perl Programmer at RiskMetrics Group, Inc. http://www.riskmetrics.com/
Acacia Fraternity, Rensselaer Chapter. Brother #734
** Manning Publications, Co, is publishing my Perl Regex book **
