Thanks a ton! I've been working with "Perl, A Beginner's Guide" for a few
days now and referencing the Camel. These scripts will definitely aid me
greatly on the UNIX systems on which I do computational chemistry.
Neema Salimi
[EMAIL PROTECTED]
>===== Original Message From [EMAIL PROTECTED] =====
>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 **
