How to remove leading and trailing whitespaces?

awk whitespace gsub removing-whitespace
user1194552 picture user1194552 · Feb 7, 2012 · Viewed 39k times · Source

I'm using awk '{gsub(/^[ \t]+|[ \t]+$/,""); print;}' in.txt > out.txt to remove both leading and trailing whitespaces.

The problem is the output file actually has trailing whitespaces! All lines are of the same length - they are right padded with spaces.

What am I missing?

UPDATE 1

The problem is probably due to the the fact that the trailing spaces are nor "normal" spaces but \x20 characters (DC4).

UPDATE 2

I used gsub (/'[[:cntrl:]]|[[:space:]]|\x20/,"") an it worked. Two strange things:

  1. Why isn't \x20 considered a control character?

  2. Using '[[:cntrl:][:space:]\x20 does NOT work. Why?

Answer

kev picture kev · Feb 7, 2012

This command works for me:

$ awk '{$1=$1}1' file.txt

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