replace new lines with commas in shell

Question

I want to replace new lines in text with coma or space but do not change the last new line.

I know of this question: How to replace newlines with tab characters? - but it does produce an tab on end instead of new line.

So far I have come with:

awk 'NR>1{printf","} {printf $1} END{printf"\n"}'

Is there an easier way to do this? This is not an assignment, I am just curious want to level up my scripting.

score 14 · Accepted Answer · edited Oct 26 '13 at 03:50

14

This might work for you:

paste -s -d, file

or

paste -s -d" " file

edited Oct 26 '13 at 03:50

Mark Reed

answered Aug 04 '13 at 08:54

potong

Netf · Answer 2 · 2013-08-04T12:02:33.420

3

This should do a job:

echo  ${$(tr '\n' ',' < file)%?}

or perhaps using sed:

sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/,/g' file

edited Aug 04 '13 at 12:02

answered Aug 04 '13 at 10:20

Netf

I was searching for something less magical, those both require quite good knowledge of `bash`/`tr` or `sed` respectively – mpapis Aug 04 '13 at 12:39

score 1 · Answer 3 · answered Oct 26 '13 at 03:56

Using perl is not quite as simple as paste, but it does generalize to more cases:

perl -0pe 's/\n(?!$)/,/g' filename  # comma
perl -0pe 's/\n(?!$)/ /g' filename  # space

The (?!$) is a lookahead assertion that means "not at the end", so the last newline is left alone.

Ranjithkumar T · Answer 4 · 2013-10-26T03:45:54.890

0

You can use sed command to remove the end ","

 # sed -i 's/,$//g' endmodify.txt

 # cat endmodify.txt
 root
 bin
 daemon
 adm
 lp
 sync
 games
 gopher

Thanks.

edited Oct 26 '13 at 03:45

answered Oct 22 '13 at 07:24

Ranjithkumar T

as you can see the result is coma at the last line, the question was how to avoid it – mpapis Oct 22 '13 at 10:06
Hi mpapis: sorry for the update: then we can use, # sed -i 's/,$//g' endmodify.txt . – Ranjithkumar T Oct 26 '13 at 03:48

4 Answers4