Typing or pasting a line of 128 characters or more into the CLI hangs the
editor and overruns cmd_buffer[128]: the length check did not reserve room
for the terminating NUL written on Enter, and on a full buffer the character
was retried via continue without advancing the serial-ring read pointer at
the bottom of the loop, so input processing never caught up again.
Cap the line at CMD_BUF_SIZE-1 and, when full, drop the character but fall
through to consume the ring byte instead of spinning on it. The functional
change is three lines; the rest of the diff is re-indentation of the
insert-and-echo block (git diff -w shows the minimal form).
Currently only ASCII DEL (key code 127) is handled as backspace, but some terminal
emulators are sending ^H which is ASCII BS (key code 8). Looks like we can
safely treat both in the same matter.
The current code for entering commands via the serial CLI is completely
refactored and moved out of rtlplayground.c into a separate file cmd_edit.c
putting code into BANK2.
The serial ring buffer sbuf[] is now exclusively used for receiving
keys, including escape sequences (DEL will generate a 4-byte escape
sequence). The command is now held in cmd_buffer. This reduces
XMEM use, because the serial buffer can be much smaller.
Supported is only editing the current command line via backspace, del,
cursor left and right.
Because the code cannot distinguish escape sequences which are not yet
complete (because the serial isr has not yet put all characters into
the serial buffer) from the dozens of unsupported ones (F-keys/home,
Page up/down, cursor up/down...) they are ignored and remain in the
serial buffer until the ring-pointer overwrites them. This is standard
behaviour for consoles, which will print out garbage for unsupported
characters. In this implementation, the command line buffer and the
visible command line in the terminal are always synced, so garbage
can be removed again by ediing the line.
The code makes several redundant checks in order to prevent race-conditions
between the serial ISR and the comand-editing code.
René van Dorst
bloqaudio
feelfree69
diijkstra
logicog