awk - Bash rows to column -

awk - Bash rows to column -

i know how transpose rows in file columns, want append lines of bottom half of file lines upper half.

like:

a1 a2 a3 b1 b2 b3

to

a1 | b1 a2 | b2 a3 | b3

the list comes 2 greps. append first grep sec one. 2 greps have same amount of hits.

i want within bash script.

what combining head , tail paste?

paste -d'|' <(head -3 file) <(tail -3 file)

it returns:

a1|b1 a2|b2 a3|b3

paste merges lines of files. if provide different lines same file... that's all!

as matter of getting head half of lines , tail rest, more generic way:

paste -d'|' <(head -n $(($(wc -l <file)/2)) file) <(tail -n $(($(wc -l <file)/2)) file)

bash awk sed grep transpose