How to remove leading and trailing whitespaces?

Question

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

The problem is the output f

Answer 1

Perl could be used:

perl -lpe 's/^\s*(.*\S)\s*$/$1/' in.txt > out.txt

s/foo/bar/ substitute using regular expressions
^ beginning of string
\s* zero or more spaces
(.*\S) any characters ending with a non-whitespace. Capture it into $1
\s* zero or more spaces
$ end of string