#357 Joining groups of lines in a text file using awk

Joining groups of lines in a text file.

The prints three consecutive lines of text on the same line, after which a linefeed is printed. This has the effect of “joining” every three consecutive lines of text.

example.txt

1
2
3
4
5
6
7
8
9

ex357.txt

awk -F" " '{
printf("%d",$0)
if(NR % 3 == 0) { printf("\n") }
}' example.txt

output:

123
456
789