Today, I was doing some command-line stuff and then this happened:
ls --help|less
Usage: ls [OPTION]... [FILE]...
List information about the FILEs (the current directory by default).
Sort entries alphabetically if none of -cftuvSUX nor --sort is specified.
Mandatory arguments to long options are mandatory for short options too.
ESC]8;;https://www.gnu.org/software/coreutils/manual/coreutils.html#ls-aESC\ESC[1m-a, --allESC[0mESC]8;;ESC\
do not ignore entries starting with .
ESC]8;;https://www.gnu.org/software/coreutils/manual/coreutils.html#ls-AESC\ESC[1m-A, --almost-allESC[0mESC]8;;ESC\
do not list implied . and ..
ESC]8;;https://www.gnu.org/software/coreutils/manual/coreutils.html#ls--authorESC\ESC[1m--authorESC[0mESC]8;;ESC\
It’s rendering ls --help with control characters. When I do ls --help|less --raw-control-chars it doesn’t show the control characters, and it looks all neat and pretty. Isn’t this the opposite of how it’s supposed to work?!
Is --raw-control-chars a toggle and some config is causing less to show control characters when I invoke it with no options? If so, where can I find this config and stop this?
This has absolutely no bearing on my work and my life in general except for the fact that I’ll go absolutely batshit trying to figure this out, because that’s how my brain is. So far, all of my web searches just confirm that less shouldn’t be working this way, but they don’t give me any way to fix it. Please help me, Lemmy!!!
When I do
ls --help|less --raw-control-charsit doesn’t show the control characters, and it looks all neat and pretty. Isn’t this the opposite of how it’s supposed to work?!You’ve gotten a longer reply to this, but just to make it clear: No, that’s how it’s supposed to work.
- By default
lessmangles control characters so they can’t do anything to your display (or bell) - With
-R,lesswill pass some control characters through raw and unmangled; enough to give you stuff like pretty colours - With
-r,lesswon’t mangle any control characters, which, if you’re doing something stupid like trying to read a binary file, can leave your terminal prompt fucked up and in need of areset.
- By default
Per the Gnu Coreutils NEWS file:
All commands now markup option names in --help and man pages, with bold attributes, and hyperlinks into the online manual on gnu.org. The links can be configured with the --enable-manual-url configure option, and the bold highlighting with --disable-bold-man-page-references. At runtime all markup can be disabled with the TERM=dumb env var value.This has nothing to do with less (or bash or fish). It is a new behavior as of Coreutils 9.10. It is to preserve the hyperlinks in the help output of ls, cp, rm, mv, etc. In default mode, less catches these control codes and escapes them so you see the visual escape codes. If you use
less --raw-control-charsthen less is NOT escaping the control characters (just passing them through) and they get interpreted by the terminal as screen formatting codes.Debian 13, which ships Coreutils 9.7 does not have the change and cannot reproduce the behavior.
You may want to tag your triple-backtick with something like
textorplainso you don’t get auto-inferred syntax highlighting. E.g:All commands now markup option names in --help and man pages,good one, thanks!
/usr/bin/ls --color=never --help | /usr/bin/lessand/usr/bin/ls --color=never --help > ~/Desktop/lshelp.txtproduces and contains the same characters, BTW. This happens in Bash and Zsh, using Kitty and Konsole terminals. So its not an issue with less, the shell or terminal. Meaning it might be an issue with ls itself. I have “ls (GNU coreutils) 9.11” fromls --version.Ah ls has an option for this:
-q, --hide-control-charsButls -q --color=never --help | lessseem not to hide anything, maybe because --help is in use. I can putstringsin between, it would only hide control characters, not the normal sequence for other stuff\ls -q --color=none --help | strings | lessLooks like an issue with ls. I feel helpless.
-qcontrols output for filenames. Fromls.c:/* True means output nongraphic chars in file names as '?'. (-q, --hide-control-chars) qmark_funny_chars and the quoting style (-Q, --quoting-style=WORD) are independent. The algorithm is: first, obey the quoting style to get a string representing the file name; then, if qmark_funny_chars is set, replace all nonprintable chars in that string with '?'. It's necessary to replace nonprintable chars even in quoted strings, because we don't want to mess up the terminal if control chars get sent to it, and some quoting methods pass through control chars as-is. */ static bool qmark_funny_chars;
I would say your
lsshouldn’t be working that way: when it detects that it’s standard output isn’t a terminal, it shouldn’t be outputting the control codes. Which makes me wonder what version of ls you are running.edit: what is the output from
alias lsand what happens if you run\ls --help | less?I’m using the fish shell. I checked, and there are no aliases for
lsorless.\ls --help | lessgives me the same result asls --help | less.What terminal are you using?
That’s surprising. I have an older version of coreutils (9.7 from Debian 13) that doesn’t produce the links and formatting. I’m running bash and the behaviour you’re experiencing isn’t reproduced.
Aliases aside, I wouldn’t expect the shell to be the cause. None the less, I installed version 4.0.2 of the fish shell and ran the same command in it and didn’t see any control characters. But that’s not really surprising - my old version of ls doesn’t produce them. So I ran
ls | lessbecause even with my versionlscolour highlights files by type, but in the pipeline to less, there were no codes.If I run
ls --color=always | lessthen I do see codes in the less output.You might check your environment variables to see if CLICOLOR_FORCE is set.
Otherwise, I am out of ideas.
What’s the value of $LESSOPEN? These URLs in a manual page look strange.
One option is to use
less -Rto see the pretty colors.
The boring option is to usels --color=neverand be sad.Yeah use less -r. You can set that in your environment
export LESS=“-EX -r”
is what I use.
Capital
-Ris for most use-cases a safer and better choice than plain-r.
From what I see you are missing spaces around pipe (the | character).
It should be
ls --help | lessThat doesn’t make any difference.
