Less provides an alternative of <C-x> to stop following, but that is intercepted by most shells.
WoW, thanks a lot! That was my pain for many years. C-x works in Gnome Console just fine.
I might be misremembering, but I think I just had to rebind <C-x> in zsh to get less working.
The shell isn’t gone, but it isn’t active either from what I understand. The function of converting the user’s typing ^Z on a terminal (or a ^Z arriving on the master end of a pseudoterminal) into a SIGTSTP signal to the terminal’s foreground process group is[1] a built-in function of the kernel, much like for ^C and SIGINT or ^\ and SIGQUIT. (The use of ^Z resp. ^C or ^\ specifically, as well as the function being active at all, is configurable via a TTY ioctl wrapped by termios wrapped in turn by `stty susp` resp. `stty intr` or `stty quit`.) So is the default signal action of stopping (i.e. suspending) the process in response to that signal. The shell just sees its waitpid() syscall return and handles the possibility of that having happened due to the process stopping rather than dying (by updating its job bookkeeping, making itself the foreground process group again, and reëntering the REPL).
I am not saying that doing job control by filtering the child’s input would be a bad design in the abstract, and it is how terminal multiplexers work for instance. I admit the idea of kernel-side support for shell job control is pretty silly, it’s just how it’s traditionally done in a Unix system.
[1] https://www.gnu.org/software/libc/manual/html_node/Concepts-...
C-z is not processed by the shell but by the terminal "infrastructure".
You can disable it, or change the key binding, and a lot more, with stty(1).
Having to set bookmarks and remember them is a PITA I can usually do without. If I'm looking at "normal" log output, it's usually set up in a nice aggregator somewhere, where I can easily exclude noise and otherwise uninteresting output.
My mind was blown when finding out its really just "keep on polling after EOF". Meaning there is absolutely no difference between opening a file normally and "following" a file - and software could easily switch between the two "modes" on the fly.
As far as following the tail of the file: if the focused line is at the end of the file, the display will scroll automatically; otherwise, the display will stick to the current position. Also, if there is a search active, matches in the new data will be found and highlighted.
This exists on IBM keyboards and is called 'Pause'. Sadly most programs don't use it.
I would say it's a bad UX and not just odd. I can't see any benefit to making it modal. It should just load new data as it becomes available without making the user do anything.
" ... desirable if the deinitialization string does something unnecessary, like clearing the screen."
I prefer to not clear the screen. I usually want to continue to refer to something or even copy/paste from the content to my current command line.
...And combined with some of the other options in the post, my go-to has been "less -SEXIER" for a long time. Specifying E twice doesn't seem to do anything except make this easier to remember.
git uses "less -FRX" by default. This is how I learned about -F.
(To be pedentic, git uses "LESS=FRX less", which accomplishes the same thing.)
Admittedly, they are a bit slow sometime and sure, you could use `grep -v` then pipe which is way faster, but they've saved me on removing noise from logfiles from time to time when you don't always know what to filter beforehand :).
EDIT: It was in TFA.
-L: skip preprocessing the input file. When opening rotated log files with the names like logfile.1, logfile.2... the default preprocessor on some distros will recognize them as man page source and helpfully pipe through nroff. If the file is largish this introduces an annoying pause. Using -L skips all that.
Ctrl-R as the first character of a search string will search for that literal string, not the regular expression. Nice if you have regex metacharacters in the search string and don't want to bother with escaping (and don't need the regex facilities, of course.)
I have a single line in my config[1] which binds s to back-scroll, so that d and s are right next to each other and I can quickly page up/down with one hand.
If you’re on macOS, you may not be able to use this unless you install less from Homebrew, or otherwise replace the default less.[2]
[1] https://github.com/jez/dotfiles/blob/master/lesskey#L2
[2] https://apple.stackexchange.com/questions/27269/is-less1-mis...
I set a mark, move to somewhere else, then save the area between where I am and the mark: ma(assign mark "a" to position), jjj(move three lines away), |a(pipe from current-position to the "a" mark then a ! prompt appears so enter...) cat >somefile (which dumps the selected text, cur-pos to mark "a", into somefile).
That was great for saving snippets of news or emails.
Also, the -j setting. Sets the line position for searches so context is available, eg using -j8 means the search is 8 lines from the top of the screen.
When a commit is "selected" (at the top line of the screen), usually after a series of n/N, I can press a shortcut that invokes an action on this commit.
Currently, I use it for two things:
1. Running git-show on a commit I'm interested in. The cool thing is that once I quit the git-show's less, I'm back to where I was in git-log's less. They stack.
2. fixup-ing a commit, after verifying with the command from 1. that it really is the one I want. I've had enough problems with git-absorb and git-fixup that I prefer to do it myself.
I detect when a particular command is running[1] and set up keyboard shortcuts that send key sequences to less and ultimately lead to the top line of the screen being piped to a short script of mine that extracts the commit hash and does something with it.
[1]: via a debug trap in bash, which sets the terminal title, which, in turn, is detected by keyd-application-mapper; other setups are possible, I used to use tmux for that.
(I usually invoke this when viewing jq output, a JSON data formatter / query tool.)
However while I think the feature is neat, a clever use of an existing feature, I never use it. I think it is sort of the same as info pages and why the technologically superior solution sort of lost to the stupider simpler man pages. Having a simple uniform interface "press / to search, all information in one document" is far less cognitively distracting than the better system.
And final thoughts: if unfamiliar the bsd's use the mdoc set of troff macros to build semantic man pages. sort of like how latex lets you build semantic documents on the tex typesetting engine. Where linux man pages are usually plain troff. OpenBSD actually went one step further and now uses a specific mandoc program to render them rather than the troff + mdoc macros that was used before.
(I suppose I could `tee`, but then I would always dump to a file even if it ends up being useless output.)
1. Do `echo '^q toggle-option -redraw-screen\nq' >> ~/.config/lesskey`
2. Make sure `less` is invoked without `-X` (or with `-+X` if you want to be sure).
This `^q` command is particularly useful for `git log` output and other things where you might need to refer back to them in the next terminal command you do. (In fact, `git` uses `less -FRX` by default, so you'd need to override its config to use `less -FR` instead for the above to work as intended). The `q` command is useful when you don't want to lose what you had on the screen before invoking `less`.
echo '^q toggle-option -redraw-on-quit\nq' >> ~/.config/lesskey
The original version I suggested works too, but by accident. `redraw-on-quit` is the actual option name.(I'd edit my original message, but it's too late for that)
----
Also, note that if you put `--redraw-on-quit` into your `LESS` config (and not `-X`), and set up `^q` as above, things will still work but with flipped behavior of `q` and `^q`.
If your version of `less` is new enough, I believe that the `--redraw-on-quit` behavior is in every way (slightly) better than the `-X` behavior. In addition to the above, some terminals have special behaviors in alternate screen (like converting mouse wheel to up/down keys), which `--redraw-on-quit` will preserve.
Also useful for privilege escalation...
If a script running as root uses less (or vi), just do "!bash" and you have a root shell. Note that systems that let you do this are usually pretty weak, and there are often many other ways to get root access, but this is a particularly simple one that I used a few times in the past.
[0]: https://github.com/gwsw/less/blob/master/README#L67-L70
https://github.com/charmbracelet/glow/compare/master...fragm...
Thought I'd tag along to this submission and see if anyone has a recommendation?
`emacs -nw -e "(view-mode)"`
But there are (at least) 150 Psalms! You're going to need more less tips to match that.