Using awk to print characters of specific index on a line

Question

Alright, so I know it is quite simple to print specific arguments of a line using $:

$ cat file
hello world

$ awk '{print $1}' file
hello

But what if I want to print chars 2 through 8? or 3 through 7? Is that possible with awk?

nims · Accepted Answer · 2012-07-09T20:03:00.513

76

awk '{print substr($0,2,6)}' file

the syntax for substr() is

substr(string,start index,length)

edited Jul 09 '12 at 20:03

answered Jul 09 '12 at 18:45

nims

Why is the field separator `-F='\n'` necessary? Or is it? – Levon Jul 09 '12 at 18:55
@Levon as i thought the OP wants to find the substring of the whole record, not the field. – nims Jul 09 '12 at 19:11
4

I'm a bit confused, not trying to argue, just to get this straight for myself. `$0` is already the whole current line, so if you are taking substrings of the current whole line, I don't see why you'd have to specify `-F` .. what am I missing here? – Levon Jul 09 '12 at 19:20
@Levon oops! Thanks for pointing it out. :) editing the answer. – nims Jul 09 '12 at 20:02

score 3 · Answer 2 · answered Jul 09 '12 at 18:53

3

Yes. You can use substr function :

In your case - for print chars from 2 through 8:

echo "hello" | awk '{ print substr( $0, 2, 6 ) }'

result is:

ello

answered Jul 09 '12 at 18:53

nick

score 2 · Answer 3 · answered Oct 07 '15 at 00:47

2

If Perl is an option:

perl -lne 'print substr($_,1,6)' file

Output is identical to answer from @nims

answered Oct 07 '15 at 00:47

Chris Koknat

I downvoted because the question is about awk, not Perl. – bfontaine Dec 05 '21 at 16:36

3 Answers3