static int completeLine(int fd, const char *prompt, char *buf, size_t buflen, size_t *len, size_t *pos, size_t cols) {
linenoiseCompletions lc = { 0, NULL };
int nwritten;
char c = 0;
completionCallback(buf,&lc);
if (lc.len == 0) {
beep();
} else {
size_t stop = 0, i = 0;
size_t clen;
while(!stop) {
/* Show completion or original buffer */
if (i < lc.len) {
clen = strlen(lc.cvec[i]);
refreshLine(fd,prompt,lc.cvec[i],clen,clen,cols);
} else {
refreshLine(fd,prompt,buf,*len,*pos,cols);
}
do {
c = linenoiseReadChar(fd);
} while (c == (char)-1);
switch(c) {
case 0:
freeCompletions(&lc);
return -1;
case 9: /* tab */
i = (i+1) % (lc.len+1);
if (i == lc.len) beep();
break;
case 27: /* escape */
/* Re-show original buffer */
if (i < lc.len) {
refreshLine(fd,prompt,buf,*len,*pos,cols);
}
stop = 1;
break;
default:
/* Update buffer and return */
if (i < lc.len) {
nwritten = snprintf(buf,buflen,"%s",lc.cvec[i]);
*len = *pos = nwritten;
}
stop = 1;
break;
}
}
}
freeCompletions(&lc);
return c; /* Return last read character */
}
static int linenoisePrompt(int fd, char *buf, size_t buflen, const char *prompt) {
size_t plen = strlen(prompt);
size_t pos = 0;
size_t len = 0;
size_t cols = getColumns();
buf[0] = '\0';
buflen--; /* Make sure there is always space for the nulterm */
/* The latest history entry is always our current buffer, that
* initially is just an empty string. */
linenoiseHistoryAdd("");
history_index = history_len-1;
if (write(1,prompt,plen) == -1) return -1;
while(1) {
char c = linenoiseReadChar(fd);
if (c == 0) return len;
if (c == (char)-1) {
refreshLine(fd,prompt,buf,len,pos,cols);
continue;
}
/* Only autocomplete when the callback is set. It returns < 0 when
* there was an error reading from fd. Otherwise it will return the
* character that should be handled next. */
if (c == 9 && completionCallback != NULL) {
c = completeLine(fd,prompt,buf,buflen,&len,&pos,cols);
/* Return on errors */
if (c < 0) return len;
/* Read next character when 0 */
if (c == 0) continue;
}
switch(c) {
case 13: /* enter */
history_len--;
free(history[history_len]);
return (int)len;
case 3: /* ctrl-c */
errno = EAGAIN;
return -1;
case 127: /* delete */
if (len > 0 && pos < len) {
memmove(buf+pos,buf+pos+1,len-pos-1);
len--;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 8: /* backspace or ctrl-h */
if (pos > 0 && len > 0) {
memmove(buf+pos-1,buf+pos,len-pos);
pos--;
len--;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 4: /* ctrl-d, remove char at right of cursor */
if (len > 1 && pos < (len-1)) {
memmove(buf+pos,buf+pos+1,len-pos);
len--;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
} else if (len == 0) {
history_len--;
free(history[history_len]);
return -1;
}
break;
case 20: /* ctrl-t */
if (pos > 0 && pos < len) {
int aux = buf[pos-1];
buf[pos-1] = buf[pos];
buf[pos] = aux;
if (pos != len-1) pos++;
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 2: /* ctrl-b */ /* left arrow */
if (pos > 0) {
pos--;
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 6: /* ctrl-f */
/* right arrow */
if (pos != len) {
pos++;
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 16: /* ctrl-p */
case 14: /* ctrl-n */
/* up and down arrow: history */
if (history_len > 1) {
/* Update the current history entry before to
* overwrite it with tne next one. */
free(history[history_index]);
history[history_index] = strdup(buf);
/* Show the new entry */
history_index += (c == 16) ? -1 : 1;
if (history_index < 0) {
history_index = 0;
break;
} else if (history_index >= history_len) {
history_index = history_len-1;
break;
}
strncpy(buf,history[history_index],buflen);
buf[buflen] = '\0';
len = pos = strlen(buf);
refreshLine(fd,prompt,buf,len,pos,cols);
}
break;
case 27: /* escape sequence */
break; /* should be handled by linenoiseReadChar */
default:
if (len < buflen) {
if (len == pos) {
buf[pos] = c;
pos++;
len++;
buf[len] = '\0';
if (plen+len < cols) {
/* Avoid a full update of the line in the
* trivial case. */
if (write(1,&c,1) == -1) return -1;
} else {
refreshLine(fd,prompt,buf,len,pos,cols);
}
} else {
memmove(buf+pos+1,buf+pos,len-pos);
buf[pos] = c;
len++;
pos++;
buf[len] = '\0';
refreshLine(fd,prompt,buf,len,pos,cols);
}
}
break;
case 21: /* Ctrl+u, delete the whole line. */
buf[0] = '\0';
pos = len = 0;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 11: /* Ctrl+k, delete from current to end of line. */
buf[pos] = '\0';
len = pos;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 1: /* Ctrl+a, go to the start of the line */
pos = 0;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 5: /* ctrl+e, go to the end of the line */
pos = len;
refreshLine(fd,prompt,buf,len,pos,cols);
break;
case 12: /* ctrl+l, clear screen */
linenoiseClearScreen();
refreshLine(fd,prompt,buf,len,pos,cols);
}
}
return len;
}
int main(void)
{
int epollFD;
epollFD = epoll_create1(EPOLL_CLOEXEC);
if (epollFD < 0) {
printf("Failed to create epollFD: %m\n");
exit(1);
}
struct epoll_event ev = {
.events = EPOLLIN | EPOLLPRI,
.data.fd = STDIN_FILENO };
int ret = epoll_ctl(epollFD, EPOLL_CTL_ADD, ev.data.fd, &ev);
if (ret < 0) {
printf("epoll_ctl() failed: %m\n");
exit(1);
}
linenoiseSetHandlerCallback(NULL, callback);
linenoiseSetPrompt("input>");
linenoiseForcedUpdateDisplay();
while(!stopped) {
#define MAX_EVENTS 10
struct epoll_event events[MAX_EVENTS];
int nfds = epoll_wait(epollFD, events, MAX_EVENTS, -1);
if (nfds < 0 ) {
printf("epoll_wait: %m\n");
if (errno == EINTR) continue;
return -1;
}
/* handle selected fds */
for (int s=0; s<nfds; s++) {
int fd = events[s].data.fd;
if (fd < 0) continue;
if (events[s].events & EPOLLIN) {
switch (fd) {
case STDIN_FILENO:
linenoiseReadChar();
break;
default:
printf("Data available on %d\n", fd);
}
}
if (events[s].events & EPOLLHUP) {
printf("HUP on sock %d\n", fd);
}
if (events[s].events & EPOLLERR) {
printf("error happened on fd %d\n", fd);
int r = epoll_ctl(epollFD, EPOLL_CTL_DEL, fd, NULL);
printf("epoll_ctl(CTL_DEL) returns %d: %m\n", r);
close(fd);
}
}
}
sleep(1);
linenoiseRemoveHandlerCallback();
printf("\n");
return 0;
}