Question

I have a list. There are some lines whose Column 1 is the same.

ENSG00000005187 chr16   19  209 0.079
ENSG00000005187 chr16   20  206 0.172

I want to cluster those lines sharing the same Column 1 into one line like below:

ENSG00000005187 chr16   19  209 0.079  chr16    20  206 0.172

How can I do it using bash?

thx

Answer 1

You can do this using awk:

awk '{ x[$1]=x[$1] " " $2 " " $3 " " $4 " " $5 } END { for (k in x) print k,x[k]; }' input.txt

That snippet assumes all your lines have exactly five fields.

By the way the join standard utility comes close to doing what you need, but unfortunately is designed to join two different files; joining a file with itself produces spurious lines. Nevertheless you should probably check it out because if you do this kind of task often you’re bound to find it useful at some time.