FAQ 4.34 How do I extract selected columns from a string?

PerlFAQ Server · *nix forums Guru Joined: 09 Apr 2005 Posts: 1008

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4.34: How do I extract selected columns from a string?

Use "substr()" or "unpack()", both documented in perlfunc. If you prefer
thinking in terms of columns instead of widths, you can use this kind of
thing:

# determine the unpack format needed to split Linux ps output
# arguments are cut columns
my $fmt = cut2fmt(8, 14, 20, 26, 30, 34, 41, 47, 59, 63, 67, 72);

sub cut2fmt {
my(@positions) = @_;
my $template = '';
my $lastpos = 1;
for my $place (@positions) {
$template .= "A" . ($place - $lastpos) . " ";
$lastpos = $place;
}
$template .= "A*";
return $template;
}

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