Added an option to disable color highlighting

[Vedaant-Rajoo]

What does it do?

Disable color display when the output is not a tty.

Why the change?

Color gives weird ANSI polluted output for non tty screens. tldr is used not only in terminals but other places like code editors like vim and emacs where this behaviour might not be simplified.

How can this be tested?

tldr tldr > tldr.md
tldr --color tldr > tldr.md
tldr tldr

Where to start code review?

parser.c

Relevant tickets?

closes #35

Questions?

<Ask us anything!>

[kbdharun]

LGTM, Thanks for your contribution and welcome to tldr.

Changes I made

When testing your code I got this error:

➜  tldr-c-client git:(feature/color-control) make
CC src/local.c
CC src/net.c
CC src/parser.c
CC src/tldr.c
src/tldr.c: In function ‘main’:
src/tldr.c:63:18: warning: implicit declaration of function ‘isatty’ [-Wimplicit-function-declaration]
   63 |     color_flag = isatty(fileno(stdout));
      |                  ^~~~~~
CC src/utils.c
LD tldr

I fixed it by including the #include <unistd.h> header.

Additionally, I made some indentation changes in code and added .vscode to the .gitignore file (I use VSCode as an IDE and it by default generates JSON configuration files inside the directory)

Now, make compiled fine and the outputted file is proper without any pollution.

➜  tldr-c-client git:(feature/color-control) make  
CC src/tldr.c
LD tldr
➜  tldr-c-client git:(feature/color-control) ✗ sudo make install
Place your right index finger on the fingerprint reader
install -d /usr/local/bin
install ./tldr /usr/local/bin
install -d /usr/local/share/man/man1
install man/tldr.1 /usr/local/share/man/man1

Output

tldr.txt

@Vedaant-Rajoo Feel free to review and comment on the changes I made.

[SethFalco]

Perhaps it's worth supporting NO_COLOR too while we're here? Or I could do it as a separate PR to streamline this one.

NO_COLOR is an informal standard/convention to disable color in command-line application output. It's usually implemented in color libraries, but since we don't use one we'd be responsible for doing it directly.

If NO_COLOR is set to any non-empty string, all colors are disabled.

[kbdharun]

Perhaps it's worth supporting NO_COLOR too while we're here? Or I could do it as a separate PR to streamline this one.

NO_COLOR is an informal standard/convention to disable color in command-line application output. It's usually implemented in color libraries, but since we don't use one we'd be responsible for doing it directly.

If NO_COLOR is set to any non-empty string, all colors are disabled.

Agreed, feel free to modify the PR.

[SethFalco]

I've added a commit, feedback welcome.

• If NO_COLOR is set, don't display color unless overridden otherwise.
• Meanwhile, the existing tty check is still there, but only performed if NO_COLOR is not set.

[SethFalco]

An issue I noticed with the branch though, it seems ./tldr -C tldr doesn't work though?

./tldr: unrecognized option '-C'

The long option works flawlessly, but before adding my commit, the short option wasn't working, I did not resolve this. 🤔

[kbdharun]

n issue I noticed with the branch though, it seems ./tldr -C tldr doesn't work though?

./tldr: unrecognized option '-C'

The long option works flawlessly, but before adding my commit, the short option wasn't working, I did not resolve this. 🤔

Interesting, I will try replicating this.

[kbdharun]

Update: Tested it right now, the force colour option works fine for me before your commit too.

I think this PR is GTG will merge it and focus on the other PR updating the man page.