NAME
ooppeennppttyy, llooggiinnttttyy, ffoorrkkppttyy - tty utility functions
SYNOPSIS
##iinncclluuddee <
int ooppeennppttyy(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp); int llooggiinnttttyy(int fd); pidt ffoorrkkppttyy(int *amaster, char *name, struct termios *termp, struct winsize *winp);> DESCRIPTION
The ooppeennppttyy(), llooggiinnttttyy(), and ffoorrkkppttyy() functions perform manipulationson ttys and pseudo-ttys.
The ooppeennppttyy() function finds an available pseudo-tty and returns file
descriptors for the master and slave in amaster and aslave. If name isnon-null, the filename of the slave is returned in name. If termp is
non-null, the terminal parameters of the slave will be set to the values
in termp. If winp is non-null, the window size of the slave will be set
to the values in winp. The llooggiinnttttyy() function prepares for a login on the tty fd (which may bea real tty device, or the slave of a pseudo-tty as returned by ooppeennppttyy())
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 ffoorrkkppttyy() function combines ooppeennppttyy(), ffoorrkk(), and llooggiinnttttyy() tocreates 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 file-
name of the slave in name if it is non-null. The termp and winp parame-
ters, if non-null, will determine the terminal attributes and window size
of the slave side of the pseudo-tty.
RETURN VALUES
If a call to ooppeennppttyy(), llooggiinnttttyy(), or ffoorrkkppttyy() is not successful, -1
is returned and errno is set to indicate the error. Otherwise, ooppeennppttyy(), llooggiinnttttyy(), and the child process of ffoorrkkppttyy() return 0, and the parent process of ffoorrkkppttyy() returns the process ID of the child process. EERRRROORRSS ooppeennppttyy() will fail if: [ENOENT] There are no available ttys.llooggiinnttttyy() will fail if iiooccttll() fails to set fd to the controlling ter-
minal of the current process. ffoorrkkppttyy() will fail if either ooppeennppttyy() or ffoorrkk() fails. FILES /dev/[pt]ty[pqrstuwxyzPQRST][0123456789abcdef]SEE ALSO
fork(2)BUGS
The names of the virtual consoles for the i386 PCVT console driver con-
flict with what would be the seventh group of pseudo-ttys, so ooppeennppttyy()
skips /dev/[pt]tyv[0123456789abcdef] while looking for pseudo-ttys.
BSD November 4, 1996 BSD