If the script is meant to be piped from curl, and is well written, it will be written so that it first defines everything as functions and then at the very end makes a single function call. This ensures that the script will only do anything if it has been completely downloaded.
For example, the script that rustup.rs tells you to pipe from curl is written in that way.
This is not sufficient. More care is required.
lsp_init() {
...
}
lsp_init
In other words, not only do you have to wrap your script in functions, but you have to ensure that any top-level function / command invocations are named such that they do not become different commands if truncated.
This is unsolvable in general, because the user can have any arbitrary names in their $PATH , such as custom personal utils in ~/.local/bin which can have any unforeseeable name.
It's much easier to just wrap the script in `()` to make it run in a subshell. bash will not run anything until it sees the closing `)` so truncated scripts are not a problem, and it also doesn't have the name collision problem.
For you, apparently. Other people do worry about it, which is why they do take care to wrap their script in functions. And my point is there's an even easier and more foolproof way than that.
>in the same way that a cosmic ray bitflip could cause a kernel bug that erases my entire drive but in reality I don't spend any time worrying about this.
Other people use ECC memory because they worry about this, and because it does measurably happen.
My shell[0] dies with a error "source file did not end with a newline". This is easily solvable in general, regardless of what's in PATH, as long as the shell works correctly. Valid text files do not end with bytes other than 0x0A.
0: That I wrote, because of bugs other than this one in bash et al, such as $FILE_WITH_SPACES.
The problem with piping is that bash will read line by line, keeping the connection open while it runs. If the connection fails for any reason, the script will stop, potentially breaking or corrupting things.
This can be prevented by first downloading the file, and then running it.