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Comment by theamk

6 years ago

That’s pretty nasty - this article is factually incorrect in probably the worst way: the code will work on author’s computer, but not for other people [0]

Not to mention that it is missing “good citizen” features like turning off colors when stdout is not a tty.

[0] https://news.ycombinator.com/item?id=18125374

9 comments

theamk

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n3t  6 years ago

> (...) the code will work on author’s computer, but not for other people

Is it actually the case?

The comment you cite says the code won't work on xterm or gnome-terminal.

I've checked with what I had available: XTerm(330) and GNOME Terminal 3.30.1 using VTE 0.54.1. On both terminals the last code sample from the post works perfectly fine as far as I can tell.

What terminal should I use to see improper behavior of the program?

inetknght  6 years ago

> “good citizen” features like turning off colors when stdout is not a tty.

Better solution: do not detect whether your output is a tty or not.

Let the user decide they want colors or not by using `--color=always` or `--color=never` or similar.

There's few things worse than writing a script and getting different output just because you're no longer running the program interactively.

  • theamk  6 years ago

    I don't see how this is supposed to work? Let's take "grep" for example -- you want both of these to work, and print color to terminal:

        grep box file.txt
    grep box file.txt | grep -v orange-box

    Having --color=always is nice sometimes, but there is a reason grep has "--color=auto" and it is the default. If we write invisible characters to file, this breaks all sorts of tools, so it is much safer and more predictable to not include them.

    • inetknght  6 years ago

      If I wanted to see just orange-box, then I would do

          grep --color=always orange-box file.txt

      But, I don't want to see just orange-box. I want to see orange-box and compare against other cases of box. So I would do:

          grep --color=always box file.txt | grep --color=always orange-box

      Without that --color=always, other cases of box will be drowned out by the noise.

      And if I wanted to write that out to a file then I would do

          grep --color=never orange-box file.txt > matches.txt

      Alternatively, I'd add a filter to the file with `ansi2txt`

          grep --color=always box file.txt | grep --color=always box | ansi2txt > no-color-matches.txt

      1 reply →

  • anitil  6 years ago

    Gah i got bit by this with 'jq'!

    > $ echo "{}" | jq > {} > $ echo "{}" | jq > out.json > jq - commandline JSON processor [version 1.5-1-a5b5cbe] ... etc ...

    Turns out when stdout isn't a tty you _must_ specify a filter (in this case '.')

sime2009  6 years ago

> Not to mention that it is missing “good citizen” features like turning off colors when stdout is not a tty.

It's a tutorial, not a 1000 page book. Some things won't be in there.

Besides, detecting stdout or tty isn't even relevant for interactive TUI applications.