Originální popis anglicky:
openpty, login_tty, forkpty - tty utility functions
Návod, kniha: Linux Programmer's Manual
#include <pty.h> /* for openpty and forkpty */
#include <utmp.h> /* for login_tty */
int openpty(int *amaster, int *aslave, char
*name, struct termios *termp, struct winsize *
winp);
int login_tty(int fd);
pid_t forkpty(int *amaster, char *name, struct
termios *termp, struct winsize *winp);
Link with -lutil.
The
openpty() function finds an available pseudo-tty and returns file
descriptors for the master and slave in
amaster and
aslave. If
name is not NULL, the filename of the slave is returned in
name.
If
termp is not NULL, the terminal parameters of the slave will be set
to the values in
termp. If
winp is not NULL, the window size of
the slave will be set to the values in
winp.
The
login_tty() function prepares for a login on the tty
fd (which
may be a real tty device, or the slave of a pseudo-tty as returned by
openpty()) by creating a new session, making
fd the controlling
terminal for the current process, setting
fd to be the standard input,
output, and error streams of the current process, and closing
fd.
The
forkpty() function combines
openpty(),
fork(), and
login_tty() to create a new process operating in a pseudo-tty. The file
descriptor of the master side of the pseudo-tty is returned in
amaster,
and the filename of the slave in
name if it is not NULL. The
termp and
winp parameters, if not NULL, will determine the
terminal attributes and window size of the slave side of the pseudo-tty.
If a call to
openpty(),
login_tty(), or
forkpty() is not
successful, -1 is returned and
errno is set to indicate the error.
Otherwise,
openpty(),
login_tty(), and the child process of
forkpty() return 0, and the parent process of
forkpty() returns
the process ID of the child process.
openpty() will fail if:
- ENOENT
- There are no available ttys.
login_pty() will fail if
ioctl() fails to set
fd to the
controlling terminal of the current process.
forkpty() will fail if either
openpty() or
fork() fails.
These functions are included in libutil, hence you'll need to add
-lutil
to your compiler commandline.
/dev/[pt]ty[pqrstuwxyzabcdePQRST][0123456789abcdef]
These are BSD functions, present in libc5 and glibc2.
Nobody knows how much space should be reserved for
name. So, calling
openpty() or
forkpty() with non-NULL
name may not be
secure.
fork(2)
