This change is in preparation to [PR 10788]. PR 10788 will make the
shell exitable which may lead to unexpected behavior in comparison to
previous usage of the shell.
To prevent this, this PR introduces two "new" functions to the shell's
API: `shell_run_once()` and `shell_run_forever()`.
`shell_run_once()` basically has the same behavior as `shell_run()` in
current master: Start a shell and continue reading lines until EOF is
reached.
`shell_run_forever()` wraps around `shell_run_once()` and restarts the
shell if it exits.
`shell_run()` is re-introduced as a back-porting alias for
`shell_run_forever()`.
As a consequence all current calls to `shell_run()` won't exit even
with [PR 10788] merged (which would add EOT as additional exit
condition for `shell_run_once()`).
[PR 10788]: https://github.com/RIOT-OS/RIOT/pull/10788
In RIOT native, sending CTRL+D to a shell started using shell_run would resulted in and
endless prompt loop. I've been unable to trigger such a behaviour
on actual hardware using a UART connection, but calling `pm_off` seemed
like a better alternative than having an `#ifdef BOARD_NATIVE`.
Fixes#9946
changed from void(*put_char)(int) to int(*putchar)(int).
This is beneficial, as now the std-libs putchar can be given as
an argument to shell_init() directly.
Compare #708.
Now the tokenization of an input line is done by the shell itself. You
may quote arguments with `"..."`. Empty arguments, supplied by `""` are
preserved. Spaces in between arguments are squasheds; spaces inside
quotes are preserved.
You cannot partially quote an argument. You must not use
- `cmd "abc`,
- `cmd abc"def"`, or
- `cmd "abc"def`.