sedawk

Concatenate Lines in Bash

Most command-line programs just operate on one line at a time.

Can I use a common command-line utility (echo, sed, awk, etc) to concatenate every set of two lines, or would I need to write a script/program from scratch to do this?

$ cat myFile
line 1
line 2
line 3
line 4

$ cat myFile | __somecommand__
line 1line 2
line 3line 4
Solution 
  • sed 'N;s/\n/ /;'

    Grab next line, and substitute newline character with space.

    seq 1 6 | sed 'N;s/\n/ /;'
1 2
3 4
5 6