This is a common approach, CLI tools often use isatty [1] to check if the output fd is a TTY or not. Try running "git log" for example; if you have many commits, it will page through "less" or $PAGER only if it sees that you're on a real TTY; but if not, it will not. Try this:
git log # PAGER undefined; uses less
PAGER=/usr/bin/head git log # pages through head, you get 10 lines
PAGER= git log # PAGER is empty; does not page
git log | cat # output is not a TTY; does not page
(also, notice that git uses colors if the output is going to a terminal, and does not if not)
I don't think I was ever bothered by the automatic paging through "less".
I'm bothered by it because whatever git command that I'm executing will put its output in a pager and when I quit the pager it's not there anymore. I want the output on the screen when I start typing the next command. Oh my God, this is such a frustrating pattern.
Another example, which I find very annoying, is `systemctl status`; when the service has... either enough log lines or wide enough lines, idk, it will helpfully page them. So checking the status of a service randomly may or may not block your terminal. I cannot stress enough that I do not want to have to look at the screen and decide interactively whether or not I need to hit q before I can run another command.
Yeah no. If I wanted to use a pager, I'd use a pager.
I want the output visible on screen after I exit the pager. If I didn't want it on screen, I'd pipe it to a file and open that in a text editor. That will disappear when I close the file. As a bonus: I can then use grep without having to repeat whatever command I used.
Even more importantly: I want the command to behave identically regardless of whether its stdin or stdout is /dev/null or a terminal or a socket or a serial port or a pipe or anything else that it can read or write with. Try writing a script when the tools themselves change how they behave whether they're running in a script or in a terminal or elsewhere. It kinda sucks.
Right. IMO this is bad behavior. I have `pager=cat` in my git config to deal with it there and several other aliases (include --no-pager) for systemd related stuff that do it to.
100% - I want to use whatever pager I might prefer at the moment, this advice violates their core principle "you make programs that are modular enough to be recombined as needed"
I find it far more convenient for tools to take options to use a pager, rather than to having to manually type "| less" for every command that I want to behave nicely. Just behave nicely by default; if I want you to behave awkwardly, I'll let you know!
For example, many pagers don't work well when stdin is line-buffered (they assume they'll see individual key presses as they happen)
Pagers can also conflict with keys that the terminal emulator is using for a different purpose. This is especially annoying when the terminal emulator is using those keys for pager-like functionality in the first place!
An example of both of these is Emacs `shell-mode`.
(I personally set `PAGER=cat` in my Bash profile, which avoids most of these shenanigans)
I don't think I was ever bothered by the automatic paging through "less".
[1]: https://man7.org/linux/man-pages/man3/isatty.3.html