/* Read up from standard input up to the first newline (\n) character,
and at most size-1 characters, into the buffer s, with echoing and
support for backspace. Returns the number of characters read. You
can check whether a full line was read by seeing whether a newline
precedes the terminating \0. */
ssize_t readline(char *s, size_t size)
{
size_t count = 0;
while (1) {
int c = getc_raw();
switch (c) {
case '\r': /* Treat as newline */
case '\n':
putc('\n');
goto stop;
break;
case 127:
if (count > 0) {
putc('\010');
putc(' ');
putc('\010');
count--;
}
break;
default:
if (count<size-1) {
putc(s[count++]=c);
}
}
}
stop:
s[count] = '\0';
return count;
}
int getc(void)
{
unsigned char ch;
uint64_t start;
/*
* For 100us we read the characters from the serial driver
* into a kfifo. This helps us not to lose characters
* in small hardware fifos.
*/
start = get_time_ns();
while (1) {
if (tstc()) {
kfifo_putc(console_input_buffer, getc_raw());
start = get_time_ns();
}
if (is_timeout(start, 100 * USECOND) &&
kfifo_len(console_input_buffer))
break;
}
kfifo_getc(console_input_buffer, &ch);
return ch;
}
/* Prompt for input, and read from standard input up to the first newline (\n)
character, with support for backspace, into dynamically reallocated buffer
buf of initial size BUFSIZE. Returns buf */
char *readline(char *prompt)
{
int c;
char *buf;
char *newbuf;
size_t bufsize = BUFSIZE;
size_t count = 0;
buf = malloc(bufsize*sizeof(char));
puts(prompt);
while (1) {
c = getc_raw();
switch (c) {
case '\r': /* Treat as newline */
case '\n':
putc('\n');
goto stop;
break;
case 127: /* handle DELelte */
if (count > 0) {
putc('\010');
putc(' ');
putc('\010');
count--;
}
break;
default:
if (count >= bufsize-1) {
bufsize *= 2;
newbuf = realloc(buf, bufsize*sizeof(char));
if (newbuf == NULL)
goto stop;
else
buf = newbuf;
}
buf[count] = c;
putc(c);
count++;
}
}
stop:
buf[count] = '\0';
newbuf = realloc(buf, (count+1)*sizeof(char));
if (newbuf == NULL)
newbuf = buf;
return newbuf;
}
/* Read character from standard input, with echoing. Returns a
non-negative integer on success, which can be casted to char. */
int getc(void)
{
char c = getc_raw();
syscall_write(stdout, &c, 1); /* Echo back at user. */
return c;
}
/* Read character from standard input, with echoing. Returns a
non-negative integer on success, which can be casted to char. */
int getc(void)
{
char c = getc_raw();
syscall_write(FILEHANDLE_STDOUT, &c, 1); /* Echo back at user. */
return c;
}
