Is there anyway to pass terminal colors through a pipe?

As a simple example, ls -l --color=always | grep ii.

When you just run the ls -l --color=always part alone, you get the filenames color coded. But adding grep ii removes the color coding and just has the grep match highlighting.

Screenshot of both examples:

In the above example I would want ii.mp3 and ii.png filenames to retain the cyan and magenta highlighting, respectively. With or without the grep match highlighting.

Question is not specific to ls or grep.

If this is possible, is there a correct term/name for it? I am unable to locate anything.

  • Onno (VK6FLAB)
    2·
    6 hours ago

    TL;DR - Essentially you’re attempting to mix two types of output, a pipe with a terminal. This is pretty much not going to work as expected.

    To make colour in a terminal, commands like ls add so-called Escape sequences, a series of bytes that your terminal knows how to interpret as colour.

    Whilst you might be able to force those characters though a pipe, they’re just characters, so if you only grab part of those characters, you’ll create invalid Escape sequences and all hell will break loose, exactly like what happens if you run cat on a binary file and the terminal display goes haywire. You can often recover using the reset command.

    This is why programs like ls and grep detect if they’re running as a terminal command or a pipe command and suppress the Escape sequences when you are sending their output to anything other than a terminal.