third_party/ulib/musl/src/misc/openpty.c

#include <fcntl.h>
#include <pty.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

/* Nonstandard, but vastly superior to the standard functions */

int openpty(int* pm, int* ps, char* name, const struct termios* tio, const struct winsize* ws) {
    int m, s, n = 0;
    char buf[20];

    m = open("/dev/ptmx", O_RDWR | O_NOCTTY);
    if (m < 0)
        return -1;

    if (ioctl(m, TIOCSPTLCK, &n) || ioctl(m, TIOCGPTN, &n))
        goto fail;

    if (!name)
        name = buf;
    snprintf(name, sizeof buf, "/dev/pts/%d", n);
    if ((s = open(name, O_RDWR | O_NOCTTY)) < 0)
        goto fail;

    if (tio)
        tcsetattr(s, TCSANOW, tio);
    if (ws)
        ioctl(s, TIOCSWINSZ, ws);

    *pm = m;
    *ps = s;

    return 0;
fail:
    close(m);
    return -1;
}