mdw@git.distorted.org.uk Git - termux-packages/blob - packages/libutil/pty.c

   1 #include <fcntl.h>
   2 #include <sys/ioctl.h>
   3 #include <sys/param.h>
   4 #include <sys/types.h>
   5 #include <stdlib.h>
   6 #include <termios.h>
   7 #include <unistd.h>
   8
   9
  10 int openpty(int* amaster, int* aslave, char* name, const struct termios* termp, const struct winsize* winp)
  11 {
  12         char buf[512];
  13
  14         int master = open("/dev/ptmx", O_RDWR);
  15         if (master == -1) return -1;
  16         if (grantpt(master) || unlockpt(master) || ptsname_r(master, buf, sizeof buf)) goto fail;
  17
  18         int slave = open(buf, O_RDWR | O_NOCTTY);
  19         if (slave == -1) goto fail;
  20
  21         /* XXX Should we ignore errors here?  */
  22         if (termp) tcsetattr(slave, TCSAFLUSH, termp);
  23         if (winp) ioctl(slave, TIOCSWINSZ, winp);
  24
  25         *amaster = master;
  26         *aslave = slave;
  27         if (name != NULL) strcpy(name, buf);
  28         return 0;
  29
  30 fail:
  31         close(master);
  32         return -1;
  33 }
  34
  35
  36 int login_tty(int fd)
  37 {
  38         setsid();
  39         if (ioctl(fd, TIOCSCTTY, NULL) == -1) return -1;
  40         dup2(fd, 0);
  41         dup2(fd, 1);
  42         dup2(fd, 2);
  43         if (fd > 2) close(fd);
  44         return 0;
  45 }
  46
  47
  48 int forkpty(int* amaster, char* name, const struct termios* termp, const struct winsize* winp)
  49 {
  50         int master, slave;
  51         if (openpty(&master, &slave, name, termp, winp) == -1) {
  52                 return -1;
  53         }
  54
  55         int pid;
  56         switch (pid = fork()) {
  57                 case -1:
  58                         return -1;
  59                 case 0:
  60                         close(master);
  61                         if (login_tty(slave)) _exit(1);
  62                         return 0;
  63                 default:
  64                         *amaster = master;
  65                         close (slave);
  66                         return pid;
  67         }
  68 }