how to put | between content lines of a text file?

Question

I have a file containing:

L1
L2
L3
.
.
.
L512

I want to change its content to :

L1 | L2 | L3 | ... | L512

It seems so easy , but its now 1 hour Im sitting and trying to make it, I tried to do it by sed, but didn't get what I want. It seems that sed just inserts empty lines between the content, any suggestion please?

possible duplicate of [sed: How can I replace a newline (\n)?](http://stackoverflow.com/questions/1251999/sed-how-can-i-replace-a-newline-n) — Kalanidhi, Jan 22 '15 at 11:20
I tried as suggested in that post, sed ':a;N;$!ba;s/\n/|/g' labellist, but it seems not to work, I also tried to put \ before | , but no work — KianStar, Jan 22 '15 at 11:25
and using -i option: sed -i ':a;N;$!ba;s/\n/|/g' labellist, I get this error: sed: 1: "labellist": extra characters at the end of l command — KianStar, Jan 22 '15 at 11:28
@MarkSetchell Paste does not work for me: `paste -sd' | ' file` gives strange spaceing. With six line I get: `L1 L2|L3 L4 L5|L6` — Jotne, Jan 22 '15 at 11:42
sorry for being late, I'm working on mac OS X , maybe its why its not working properly with me? — KianStar, Jan 22 '15 at 11:48
@Jotne, the delimiter in `paste -d` should be 1 character, otherwise it is treated as a *set* of characters, and each char is used in turn. — glenn jackman, Jan 22 '15 at 11:50
@KianStar Some strange that you did accept a solution that did not work (fixed now) when there was other good working solution. — Jotne, Jan 22 '15 at 12:16
Jotne I accepted it because the awk option suggested by hek2mgl worked for me. — KianStar, Jan 23 '15 at 17:52

score 1 · Answer 1 · answered Jan 22 '15 at 11:36

1

Here is one sed

sed ':a;N;s/\n/ | /g;ta' file
L1 | L2 | L3 | ... | L512

And one awk

awk '{printf("%s%s",sep,$0);sep=" | "} END {print ""}' file
L1 | L2 | L3 | ... | L512

answered Jan 22 '15 at 11:36

Jotne

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hek2mgl · Accepted Answer · 2015-01-22T12:14:50.217

1

With sed this requires to read the whole input into a buffer and afterwards replace all newlines by |, like this:

sed ':a;N;$!ba;s/\n/ | /g' input.txt

Part 1 - buffering input

:a defines a label called 'a' N gets the next line from input and appends it to the pattern buffer $!ba jumps to a unless the end of input is reached

Part 2 - replacing newlines by |

s/\n/|/ execute the substitute command on the pattern buffern

As you can see, this is very inefficient since it requires to:

read the complete input into memory
operate three times on the input: 1. reading, 2. substituting, 3. printing

Therefore I would suggest to use awk which can do it in one loop:

awk 'NR==1{printf $0;next}{printf " | "$0}END{print ""}' input.txt

edited Jan 22 '15 at 12:14

answered Jan 22 '15 at 11:43

hek2mgl

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To get newline at end put `END {print ""}` to the `awk` – Jotne Jan 22 '15 at 11:48
For some reason `sed` only works for me with first two lines. Rest are ignored. – Jotne Jan 22 '15 at 12:10
Which version of sed are you using? – hek2mgl Jan 22 '15 at 12:10
@Jotne My fault! I missed the `/g` option. Now it works as expected, I have also tried with `sed --posix` to get sure it works with all posix compatible versions of `sed`. – hek2mgl Jan 22 '15 at 12:14
Works ok now. This is why I always post output of my command in the solution (if its not to long) – Jotne Jan 22 '15 at 12:17
Yeah, this mostly makes sense. Thanks for pointing out the error for me in this case! – hek2mgl Jan 22 '15 at 12:19

score 0 · Answer 3 · answered Jan 22 '15 at 11:50

0

perl -pe 's/\n/ |/g unless(eof)' file

answered Jan 22 '15 at 11:50

Vijay

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You should add a space after `|` to get it correct :) – Jotne Jan 22 '15 at 11:52

score 0 · Answer 4 · answered Jan 22 '15 at 12:20

0

if space between | is not mandatory

tr "\n" '|' YourFile

answered Jan 22 '15 at 12:20

NeronLeVelu

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This is just the same as Wintermute posted and gives an extra `|` at end of line, and does not give space around `|` – Jotne Jan 22 '15 at 12:58
1

sorry didn't see Wintermute answer (and still not). Good point for the last `|` so it need at least a pipe sequence wioth a sed or similar. – NeronLeVelu Jan 22 '15 at 13:42
Wintermute did delete his anwer since it did not give correct output. If you have more than 10000 points you can see the deleted answer. – Jotne Jan 22 '15 at 15:56

score -1 · Answer 5 · answered Jan 22 '15 at 11:45

-1

Several options, including those mentioned here:

paste -sd'|' file
sed ':a;N;s/\n/ | /g;ta' file
sed ':a;N;$!ba;s/\n/ | /g' file
perl -0pe 's/\n/ | /g;s/ \| $/\n/' file
perl -0nE 'say join " | ", split /\n/' file
perl -E 'chomp(@x=<>); say join " | ", @x' file
mapfile -t ary < file; (IFS="|"; echo "${ary[*]}")
awk '{printf("%s%s",sep,$0);sep=" | "} END {print ""}' file

answered Jan 22 '15 at 11:45

glenn jackman

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`past` does not work with `|`. This is just a collection of others post here :( (except perl and map) – Jotne Jan 22 '15 at 11:50

how to put | between content lines of a text file?

5 Answers5