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From: John Bokma <postmas...@castleamber.com>
Newsgroups: nl.comp.os.linux.programmeren
Subject: Re: Rekenbewerking op text file
Date: 22 Feb 2005 17:58:52 GMT
Organization: Castle Amber - software development
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Koos Pol wrote:

> my $line;
> my ($be, $ae); # before equal sign, after equal sign

declareer vars waar je ze gebruikt. Daarnaast, $before_equal, 
$after_equal had je dat commentaar kunnen besparen :-D.

> my @numbers;
> while ($line = <DATA>) {

while ( my $line = <DATA> )

>     ($be, $ae) = split /=/, $line;

      dus hier: my ( $be, $ae )

Andere oplossing:

my ( @numbers ) = $line =~ /(\d+\.\d+)/g;

>     @numbers = map {$_ * 4} @numbers;
>     print join " ", map {"[$_]"} @numbers;
>     print "\n";

print "[",

    join ( "] [", map { $_ * 4 } @numbers ),

    "]\n";

Als de getallen in een bestand staan, kan:

#!perl -n

use strict;
use warnings;

my ( @numbers ) = $_ =~ /(\d+\.\d+)/g;

print "[",

    join ( "] [", map { $_ * 4 } @numbers ),

    "]\n";


handig zijn (zie perl -h voor de -n optie)

Of wellicht:

#!perl -n

use strict;
use warnings;

my ( $stamp, @numbers ) = split /[=,]/;
my $count = pop @numbers;

print "$stamp=",

    join ( ",", map { $_ * 4 } @numbers ),

    ",$count";

( merk op dat $count de \n nog bevat )

En een meer awky oplossing:

#!perl -naF[=,]
printf "%14s=%0.02f,%0.02f,%0.02f,%0.02f,%d\n",
    $F[ 0 ], ( map { $_ * 4 } @F[ 1..4 ] ), $F[ 5 ];

De "one liner" is left as an excercise ;-)


( merk op: %14s ipv %14d, getal was hier te groot (WinXP) )

-- 
John Bokma
                 Voorbeeldscripts in Perl: http://johnbokma.com/perl/
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