Three ways to change a space delimited file to a tab delimited file

Let's create a space delimited file:

tommy@tommy-ThinkPad-T420:~$ cat > new.txt
chr1 100 200
chr2 300 400
chr3 240 700

ctrl + D to indicate cat that this is the last line.

use awk:

tommy@tommy-ThinkPad-T420:~$ cat new.txt | awk -F ' ' '{print $1"\t"$2"\t"$3}'

chr1    100 200

chr2    300 400

chr3    240 700

use sed:

tommy@tommy-ThinkPad-T420:~$ cat new.txt | sed 's/ /\t/g'   

chr1    100  200

chr2    300 400

chr3    240 700

use tr :

tommy@tommy-ThinkPad-T420:~$ cat new.txt | tr ' ' '\t'   

chr1    100 200

chr2 300 400

chr3 240 700

tommy@tommy-ThinkPad-T420:~$ rm new.txt

you can redirect the newly generated tab delimited file to a new file

tommy@tommy-ThinkPad-T420:~$ cat new.txt | tr ' ' '\t' > new1.txt

Linux commands are so cool!