nodemcu-firmware/components/lua/common/linput.c

109 lines
2.6 KiB
C

#include "platform.h"
#include "linput.h"
#include "lua.h"
#include "lauxlib.h"
#include <stdio.h>
#include <string.h>
static struct input_state {
char *data;
int line_pos;
size_t len;
const char *prompt;
char last_nl_char;
} ins = {
.prompt = "? ", // prompt should never be allowed to be null
};
#define NUL '\0'
#define BS '\010'
#define CR '\r'
#define LF '\n'
#define DEL 0x7f
#define BS_OVER "\010 \010"
bool input_echo = true;
bool run_input = true;
void input_setprompt (const char *prompt) {
if (prompt == NULL)
{
fprintf(stderr, "Error: attempted to set a null prompt?!");
return;
}
ins.prompt = prompt;
}
/*
** The input state (ins) is private, so input_setup() exposes the necessary
** access to public properties and is called in user_init() before the Lua
** enviroment is initialised.
*/
void input_setup(int bufsize, const char *prompt) {
// Initialise non-zero elements
ins.data = malloc(bufsize);
ins.len = bufsize;
// Call to get the prompt error checking
input_setprompt(prompt);
}
size_t feed_lua_input(const char *buf, size_t n)
{
for (size_t i = 0; i < n; ++i) {
char ch = buf[i];
if (!run_input) // We're no longer interested in the remaining bytes
return i;
/* handle CR & LF characters and aggregate \n\r and \r\n pairs */
char tmp_last_nl_char = ins.last_nl_char;
/* handle CR & LF characters
filters second char of LF&CR (\n\r) or CR&LF (\r\n) sequences */
if ((ch == CR && tmp_last_nl_char == LF) || // \n\r sequence -> skip \r
(ch == LF && tmp_last_nl_char == CR)) // \r\n sequence -> skip \n
{
continue;
}
/* backspace key */
if (ch == DEL || ch == BS) {
if (ins.line_pos > 0) {
if(input_echo) fwrite(BS_OVER, strlen(BS_OVER), 1, stdout);
ins.line_pos--;
}
ins.data[ins.line_pos] = 0;
continue;
}
/* end of data */
if (ch == CR || ch == LF) {
ins.last_nl_char = ch;
if (input_echo) putchar(LF);
if (ins.line_pos == 0) {
/* Get a empty line, then go to get a new line */
fwrite(ins.prompt, strlen(ins.prompt), 1, stdout);
fflush(stdout);
} else {
ins.data[ins.line_pos++] = LF;
lua_input_string(ins.data, ins.line_pos);
ins.line_pos = 0;
}
continue;
}
else
ins.last_nl_char = NUL;
if(input_echo) putchar(ch);
/* it's a large line, discard it */
if ( ins.line_pos + 1 >= ins.len ){
ins.line_pos = 0;
}
ins.data[ins.line_pos++] = ch;
}
return n; // we consumed/buffered all the provided data
}