termux-packages/packages/libutil/pty.c

69 lines
1.3 KiB
C

#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/types.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
int openpty(int* amaster, int* aslave, char* name, const struct termios* termp, const struct winsize* winp)
{
char buf[512];
int master = open("/dev/ptmx", O_RDWR);
if (master == -1) return -1;
if (grantpt(master) || unlockpt(master) || ptsname_r(master, buf, sizeof buf)) goto fail;
int slave = open(buf, O_RDWR | O_NOCTTY);
if (slave == -1) goto fail;
/* XXX Should we ignore errors here? */
if (termp) tcsetattr(slave, TCSAFLUSH, termp);
if (winp) ioctl(slave, TIOCSWINSZ, winp);
*amaster = master;
*aslave = slave;
if (name != NULL) strcpy(name, buf);
return 0;
fail:
close(master);
return -1;
}
int login_tty(int fd)
{
setsid();
if (ioctl(fd, TIOCSCTTY, NULL) == -1) return -1;
dup2(fd, 0);
dup2(fd, 1);
dup2(fd, 2);
if (fd > 2) close(fd);
return 0;
}
int forkpty(int* amaster, char* name, const struct termios* termp, const struct winsize* winp)
{
int master, slave;
if (openpty(&master, &slave, name, termp, winp) == -1) {
return -1;
}
int pid;
switch (pid = fork()) {
case -1:
return -1;
case 0:
close(master);
if (login_tty(slave)) _exit(1);
return 0;
default:
*amaster = master;
close (slave);
return pid;
}
}