The Linux Programming Interface

Pseudoterminals 1387

q mfd = ptyMasterOpen(slname, MAX_SNAME);
if (mfd == -1)
return -1;

w if (slaveName != NULL) { / Return slave name to caller /
if (strlen(slname) < snLen) {
strncpy(slaveName, slname, snLen);

} else { /* 'slaveName' was too small */

close(mfd);

errno = EOVERFLOW;

return -1;

}

}

e childPid = fork();

if (childPid == -1) { /* fork() failed */

savedErrno = errno; /* close() might change 'errno' */

close(mfd); /* Don't leak file descriptors */

errno = savedErrno;

return -1;

}

r if (childPid != 0) { / Parent /
masterFd = mfd; / Only parent gets master fd /
return childPid; / Like parent of fork() */
}

/* Child falls through to here */

t if (setsid() == -1) / Start a new session /
err_exit("ptyFork:setsid");

y close(mfd); / Not needed in child /

u slaveFd = open(slname, O_RDWR); / Becomes controlling tty /
if (slaveFd == -1)
err_exit("ptyFork:open-slave");

i#ifdef TIOCSCTTY / Acquire controlling tty on BSD /
if (ioctl(slaveFd, TIOCSCTTY, 0) == -1)
err_exit("ptyFork:ioctl-TIOCSCTTY");
#endif

o if (slaveTermios != NULL) / Set slave tty attributes /
if (tcsetattr(slaveFd, TCSANOW, slaveTermios) == -1)
err_exit("ptyFork:tcsetattr");

a if (slaveWS != NULL) / Set slave tty window size /
if (ioctl(slaveFd, TIOCSWINSZ, slaveWS) == -1)
err_exit("ptyFork:ioctl-TIOCSWINSZ");