No usable output or panic when not outputting to a terminal

[yannleretaille]

Example 1

#~> lsd -a | wc
thread 'main' panicked at 'failed to retrieve terminal size', /home/yann/.cargo/registry/src/github.com-1ecc6299db9ec823/lsd-0.6.1/src/display.rs:29:21

Expected behavior: properly pipe contents to next program, expecting infinite width (e.g. "0")

Example 2

#~> lsd -al > test

Test now contains a lot of unprintable characters, e.g. it looks like this:

�[38;5;33md�[0m�[38;5;40mr�[38;5;192mw�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[0m  �[38;5;230myann�[0m  �[38;5;187musers�[0m  �[38;5;229m    4 KB�[0m  �[38;5;40mWed Dec  5 04:44:57 2018�[0m  �[38;5;33m  .git/�[0m
�[38;5;33md�[0m�[38;5;40mr�[38;5;192mw�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[0m  �[38;5;230myann�[0m  �[38;5;187musers�[0m  �[38;5;229m    4 KB�[0m  �[38;5;40mWed Dec  5 04:23:13 2018�[0m  �[38;5;33m  src/�[0m
�[38;5;33md�[0m�[38;5;40mr�[38;5;192mw�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[38;5;40mr�[38;5;168m-�[38;5;124mx�[0m  �[38;5;230myann�[0m  �[38;5;187musers�[0m  �[38;5;229m    4 KB�[0m  �[38;5;40mWed Dec  5 04:24:43 2018�[0m  �[38;5;33m  target/�[0m
�[38;5;184m.�[0m�[38;5;40mr�[38;5;192mw�[38;5;168m-�[38;5;40mr�[38;5;168m--�[38;5;40mr�[38;5;168m--�[0m  �[38;5;230myann�[0m  �[38;5;187musers�[0m  �[38;5;229m   26 B �[0m  �[38;5;40mWed Dec  5 04:23:13 2018�[0m  �[38;5;184m  .gitignore�[0m
�[38;5;184m.�[0m�[38;5;40mr�[38;5;192mw�[38;5;168m-�[38;5;40mr�[38;5;168m--�[38;5;40mr�[38;5;168m--�[0m  �[38;5;230myann�[0m  �[38;5;187musers�[0m  �[38;5;229m  119 B �[0m  �[38;5;40mWed Dec  5 04:23:13 2018�[0m  �[38;5;184m  .travis.yml�[0m
...

Expected behavior: don't print escape/color codes when not outputting to a terminal

Proposed solution

1. fetch terminal_size() at program startup and cache the result.
2. If term_size is None, disable color formatting for all outputs
3. If term_size is None, either set a reasonable default width for text files in print_grid or just default to print_one_per_line instead

[Peltoche]

Hello @yannleretaille,

Thanks for the report! The terminal_size trick seem a good idea. It think it will be easier to refactor the color package into a struct before.