Ergonomic way to search man pages
You often have to read man pages to use Linux/Unix software. However, many man pages are not easy to read. They are very long, not always conveniently arranged, and man
does not appear to have any way to handle indices or sections. A great example is man rsync
.
I am often in a situation where some popular tool has a LOOONG man page, and I just need to look up the one argument about a specific thing. I don't like having to read the whole thing just for one tiny part of it. It takes a long time, breaks my flow, and if I try to read it start to finish, I am usually very confused and overwhelmed by the time I get to the end. The default pager (I think less
) lets me search with /
, but it's not very user friendly and it's easy to end up with an too general or too specific search string.
I've been resorting to stuff like man rsync | rg -C 3 symlink
, which is much nicer. However, this is still a bit too dumb sometimes. For example, man pacman | rg -C 3 owns
does find the switch that tells you what package provides a file, but then you still have to dig through the man page to figure out that it's in the section of switches applicable to -S
(which is much higher in the page so ripgrep's context switch doesn't help).
Man pages have been around for half a century. Surely in this time, someone has come out with a way to peruse them that's better than this?
PS: For other people, there are tools like https://tldr.sh/ and https://github.com/cheat/cheat that provide shorter, alternate manual pages. Unfortunately these don't work for my question because they are not comprehensive - they obviously omit many details of the man page, and also there is not always a tldr page for every man page.
2 answers
Unix systems are made out of many small tools that focus on specific tasks but are general enough that the investment made in learning their specific switches and hotkeys pays off over many applications.
In that spirit, I would encourage you to get to know less
better. It's not a tool specifically designed for the one use case of reading man pages; it's a general purpose tool that will come in handy in many situations, which is why learning how to use it well is worth the small ergonomic cost you'd be sacrificing by not using (or writing, as I don't know of such software) a program specifically designed to make reading man pages newbie-friendly.
Did you know:
- Anything that you can tell
less
on the command line, you can toggle while you are viewing what you're viewing—to turn strict case sensitivity on or off, just type-i
(the exact same characters you'd use on the command line to turn this mode on). -
less
's filters give a great way to find a specific occurrence of a string when you don't know exactly what you're looking for. As you brought it up as an example, here's how I look for something to do with symlinks inman rsync
. I'd type&symlink⏎⃣
to view a list of all the lines with the wordsymlink
in them. That's a lot of results; I'd type/↑⃣
to highlight the word I just used to filter. Let's say that I'm interested in the line near the bottom of the results that says, ‘Symbolic links are considered unsafe if they are absolute symlinks’. Sometimes I'd typeJ
to move down the list until that line is at the top of the screen (J
, as opposed toj
or down arrow, will keep moving the screen even ifless
is at the end of its content—very useful in this context), but in this case, I'm more likely to type/unsafe⏎⃣
(which searches within the already filtered results) and typen
a much smaller number of times to get to the interesting line. Then I'll type&⏎⃣
to turn off the filter, and now I'm viewing that line in context in the full man page. - Want a table of contents for the man page? Use filters again:
&^[^ ]⏎⃣
shows only the section headers.J
will move down them until I have arrived at the section I want, and then&⏎⃣
‘expands’ it. - Do you frequently fat-finger regexes like the above? You can store custom commands in lesskey files: add the command
toc filter \^[\^ ]\r
and now you just have to remembertoc
. (The standard location for lesskey files is~/.config/lesskey
, and you can learn how to write one withman lesskey
.)
All of this might seem a little arcane as ways to accomplish things like ‘view a table of contents’, but once you start to mentally decompose those problems into smaller, more general problems (like ‘display lines matching a filter’ and ‘test if a line is a section header’), a solid familiarity with the capabilities of tried-and-true Unix tools will serve you well.
0 comment threads
Not a real answer, but these days there are some nice LLM models and they're good at summarizing text. If you have the CLI scripts to interact with them, you can submit the man page as the "system prompt" (in ChatGPT parlance) and ask the question in the "user prompt".
This will be somewhat slow and will cost you money (API credits), but it is technically quite versatile. It is also possible for the LLM to hallucinate incorrect stuff.
1 comment thread