Limit source code to 80 chars, and declare functions return type and
modifiers on a separate line.
This allows to avoid very long lines, and all function names are
aligned.
(We do this on VLC, and I like it.)
The common command.c handled process errors from system-specific int
values (errno).
Rather, expose a new enum process_result to handle error cause in a
generic way.
There are many user who encounters missing adb.
To stop things happens again, we check it and show
sexy response to user.
Signed-off-by: yuchenlin <npes87184@gmail.com>
A missing initialization (fixed by the previous commit) leaded to kill
unexpected process.
In order to prevent consequences of similar errors in the future, never
call kill() with a non-positive PID.
See <https://github.com/Genymobile/scrcpy/issues/182>.