CODEWITHSUNDEEP
bashawksed
Lenna
Lenna

Reputation: 1280

Bash merge file lines

I have a file that holds output from a test.

test 1  
42  
test 2  
69  
test 3  
420  
test 4  
55378008

I would like to make the test output appear on the same line as the test name. like so:

test 1:    42  
test 2:    69  
test 3:    420  
test 4:    55378008

I am sure there is some fancy sed, awk or perl way to do this but I am stuck.

Upvotes: 3

Views: 261

Answers (6)

Polar Bear
Polar Bear

Reputation: 6798

Bash solution

skips empty lines

process both UNIX/DOS format 'end of line'

accepts filename as argument or otherwise reads data from STDIN

#!/bin/bash

while read p1
do
  [[ -z $p1 ]] && continue
  # p1=`echo -n $p1 | tr -d "\r"`  # replaced with following line
  p1=${p1//$'\r'/}
  read p2
  echo -n "$p1: $p2"
done < ${1:-/dev/stdin}

Output

test 1: 42
test 2: 69
test 3: 420
test 4: 55378008

NOTE: no empty lines allowed between lines for join

Upvotes: 0

ikegami
ikegami

Reputation: 385590

Just replace the line feed of odd lines with :␠.

perl -pe's/\n/: / if $. % 2'

You have mentioned that you want to removing leading and trailing whitespace as well. For that, you can use the following:

perl -pe's/^\h+|\h+$/g; s/\n/: / if $. % 2'

Specifying file to process to Perl one-liner

Upvotes: 2

Jetchisel
Jetchisel

Reputation: 7781

A shell solution, which is very slow on large set of data/files.

while IFS= read -r odd_line; do
  IFS= read -r even_line
  printf '%s: %s\n' "$odd_line" "$even_line"
done < file.txt

On the other hand if the colon is not a requirement paste can do the job.

paste - - < file.txt

Upvotes: 1

Sundeep
Sundeep

Reputation: 23667

pr has this built-in, but if you need whitespace adjustment as well, then sed/awk/perl solutions suggested in other answers will suit you better

$ pr -2ats': ' ip.txt 
test 1: 42
test 2: 69
test 3: 420
test 4: 55378008

This combines 2 lines at a time with : as the separator.

Upvotes: 3

luciole75w
luciole75w

Reputation: 1117

And here is another one in sed flavor to complete the offer :

sed 'N ; s/\n/: /' input_file

For each (odd) line starting from the first, append the next (even) one in pattern space separated by a LF, then just replace this LF by :.

Upvotes: 5

Freddy
Freddy

Reputation: 4688

awk 'FNR%2{printf "%s: ", $0; next}1' file

This prints odd lines with suffix : and without newline and even lines with a newline.

Upvotes: 3

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