3 ms·

That's already a solved problem though, with a different solution - programs should be checking `isatty()` and not output escape sequences if it's not going to

by DSMan195276 3y ago

That's already a solved problem though, with a different solution - programs should be checking `isatty()` and not output escape sequences if it's not going to a real tty. That's how `ls` can display colors by default but still not have them show up if you pipe `ls` into a command. This page seems to purely be about interactive use with no color.

kevin_thibedeau 3y ago
The isatty() check is obnoxious when you do want to preserve the control chars and can't force it on.
- doix 3y ago
  That's a pretty niche case, you can force it by either allocating a pseudo tty or using LD_PRELOAD with an isatty() shim that returns true. I only ever had to do it once (using LD_PRELOAD) because there was an insane vendor binary blob that would return "SUCCESS" in green/red depending on if it passed or failed. When isatty() returned false, it was impossible to tell if it passed or failed, but the software was pure garbage.
  - kps 3y ago
    > That's a pretty niche case I don't entirely agree. When I do want colour (generally because I've taken the time to configure the program suitably for it), then I usually still want the colour when I pipe its output through a pager. `diff` is the canonical example. Edit: Another comment¹ points out pipetty² as a workaround, so I learned something useful today. ¹ https://news.ycombinator.com/item?id=36102160 https://news.ycombinator.com/item?id=36102160 ² https://github.com/kilobyte/colorized-logs https://github.com/kilobyte/colorized-logs
- franga2000 3y ago
  That's why you pair it with a command line switch: --color=auto (default, isatty + termcap) --color=always --color=never Now if we could only agree on a standard to do this using environment variables... Unfortunately, the most widely known "standard" [0], is still very rarely supported. [0] https://bixense.com/clicolors/ https://bixense.com/clicolors/

kevin_thibedeau 3y ago

The isatty() check is obnoxious when you do want to preserve the control chars and can't force it on.

doix 3y ago
That's a pretty niche case, you can force it by either allocating a pseudo tty or using LD_PRELOAD with an isatty() shim that returns true. I only ever had to do it once (using LD_PRELOAD) because there was an insane vendor binary blob that would return "SUCCESS" in green/red depending on if it passed or failed. When isatty() returned false, it was impossible to tell if it passed or failed, but the software was pure garbage.
- kps 3y ago
  > That's a pretty niche case I don't entirely agree. When I do want colour (generally because I've taken the time to configure the program suitably for it), then I usually still want the colour when I pipe its output through a pager. `diff` is the canonical example. Edit: Another comment¹ points out pipetty² as a workaround, so I learned something useful today. ¹ https://news.ycombinator.com/item?id=36102160 https://news.ycombinator.com/item?id=36102160 ² https://github.com/kilobyte/colorized-logs https://github.com/kilobyte/colorized-logs
franga2000 3y ago
That's why you pair it with a command line switch: --color=auto (default, isatty + termcap) --color=always --color=never Now if we could only agree on a standard to do this using environment variables... Unfortunately, the most widely known "standard" [0], is still very rarely supported. [0] https://bixense.com/clicolors/ https://bixense.com/clicolors/