In Perl, how can I use regular expressions to skip input lines containing digits?

Question

I've got a list like this:

Bicycles: Childrens  
289  
Bicycles: Mountain Bikes  
928  
Bicycles: Road Bikes  
870  
Camping & Outdoors Equipment  
761  
Canoes, Kayaks, Row-Boats  
231  
Climbing Equipment  
120  
Freeweights and Home Gyms  
583  
GPS and Locators  
104  
Golf Equipment  
1,223  
Other Fitness Equipment  
668

I just need to skip lines that are numbers or blank

if (($line =~ /0..9/) || ($line eq "")){}  
else{

What behavior OP wants for lines with mix content, such as "I am number 1" ..? — Ωmega, Apr 14 '12 at 20:53

score 1 · Answer 1 · answered Apr 14 '12 at 16:17

1

print $line if $line !~ /[0-9]/ and $line =~ /\S/;

perldoc perlre. You'll learn more if you put some effort into it.

answered Apr 14 '12 at 16:17

Sinan Ünür

116,958
15
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:-) if (( $line =~ /[0-9]/ or $line eq "")){} – t a Apr 14 '12 at 16:31
Please explain what you mean by that comment using English. I wrote the line in my answer for a specific reason: 1) I do not know if you `chomp`ed input 2) You use the word ***blank*** referring to a line and a line containing nothing but blanks is still a blank line to me, and 3) I do not like empty blocks following `if`s. The line above says "`print` if the line does not contain any digits and it contains some non-space characters. If you need something else, say so. – Sinan Ünür Apr 14 '12 at 17:31
I'm sorry. I just modified your answer to work with my code. It's not a crucial script. It worked great. Thanks – t a Apr 14 '12 at 18:15

score 1 · Accepted Answer · answered Apr 14 '12 at 20:03

If you write

while (<>) {
  next unless /[^\d,\s]/;
    :
}

your program will skip all lines that contain only digits, commas, and whitespace.

This program shows the idea

use strict;
use warnings

while (<DATA>) {
  next unless /[^\d,\s]/;
  print;
}

__DATA__
Bicycles: Childrens  
289  
Bicycles: Mountain Bikes  
928  
Bicycles: Road Bikes  
870  
Camping & Outdoors Equipment  
761  
Canoes, Kayaks, Row-Boats  
231  
Climbing Equipment  
120  
Freeweights and Home Gyms  
583  
GPS and Locators  
104  
Golf Equipment  
1,223  
Other Fitness Equipment  
668

output

Bicycles: Childrens  
Bicycles: Mountain Bikes  
Bicycles: Road Bikes  
Camping & Outdoors Equipment  
Canoes, Kayaks, Row-Boats  
Climbing Equipment  
Freeweights and Home Gyms  
GPS and Locators  
Golf Equipment  
Other Fitness Equipment

Ωmega · Answer 3 · 2012-04-14T20:47:04.850

0

if ($line !~ /^[\d,]*[\n\r]*$/) {
  # do something
}   
else {
  # blank or "digits & comas" only line
}

By "blank" I mean empty string with optional end of line (in case you don't use chomp)

edited Apr 14 '12 at 20:47

answered Apr 14 '12 at 20:32

Ωmega

42,614
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134
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score 0 · Answer 4 · answered Apr 15 '12 at 08:48

0

next if (!$line || $line != int($line));

First is blank values check, the second one checks whether this value is integer or not.

answered Apr 15 '12 at 08:48

Shay

41
3

In Perl, how can I use regular expressions to skip input lines containing digits?

4 Answers4