Why doesn't `less` show bold output?

Question

I'm connected to a bash shell on my ubuntu 16.04 server using Putty on Windows.

This is what it looks like in Putty when I do sudo fdisk -l:

But when I try to pipe the output into less, the colors are not shown:

I have tried sudo fdisk -l | less -R and sudo fdisk -l | less -r, but the output never looks the same as the raw output.

How can I get the output from less to look the same?

The problem was getting fdisk to output colors when piped more than getting less to retain colored output. — localhost, Oct 22 '16 at 06:49
@localhost the answer is the same, so it's actually a duplicate — phuclv, Oct 22 '16 at 10:02
@LưuVĩnhPhúc nowhere in that question do I see fdisk mentioned. The arguments are the same, but someone reading that question could not know that fdisk happens to have the same color argument as git diff. — localhost, Oct 22 '16 at 10:08

score 11 · Answer 1 · answered Oct 22 '16 at 06:19

11

The culprit is not less, but fdisk: Many programs only color their output when they print to a terminal, and don't color it when the output is redirected, because in general you want to avoid breaking scripts with the ESC-codes used for colors.

However, usually these programs also have switches to manually turn on coloring. So try

sudo fdisk --color=always -l | less

instead, and look it up in the man-page for other commands.

answered Oct 22 '16 at 06:19

dirkt

32,309

4

Actually, try ... | less -R. – Satō Katsura Oct 22 '16 at 06:25
not only fdisk but most other programs don't output color when piping, try ls or grep – phuclv Oct 22 '16 at 09:58
1

No colored output in less for the ls command, less and grep: Getting colored results when using a pipe from grep to less – phuclv Oct 22 '16 at 10:01
@SatoKatsura: Make that an answer? – dirkt Oct 22 '16 at 16:01

Why doesn't `less` show bold output?

1 Answers1