ttyname(3) [osx man page]

TTYNAME(3)						   BSD Library Functions Manual 						TTYNAME(3)

NAME

     isatty, ttyname, ttyslot -- get name of associated terminal (tty) from file descriptor

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     int
     isatty(int fildes);

     char *
     ttyname(int fildes);

     int
     ttyslot(void);

DESCRIPTION

     These functions operate on the system file descriptors for terminal type devices.	These descriptors are not related to the standard I/O FILE
     typedef, but refer to the special device files found in /dev and named /dev/ttyxx and for which an entry exists in the initialization file
     /etc/ttys.  (See ttys(5).)

     The isatty() function determines if the file descriptor fildes refers to a valid terminal type device.

     The ttyname() function gets the related device name of a file descriptor for which isatty() is true.

     The ttyslot() function fetches the current process' control terminal number from the ttys(5) file entry.

RETURN VALUES

     The ttyname() function returns the null terminated name if the device is found and isatty() is true; otherwise, a NULL pointer is returned.

     The ttyslot() function returns the unit number of the device file if found; otherwise, the value zero is returned.

FILES

     /dev/*
     /etc/ttys

SEE ALSO

     ioctl(2), ttys(5)

HISTORY

     A isatty(), ttyname(), and ttyslot() function appeared in Version 7 AT&T UNIX.

BUGS

     The ttyname() function leaves its result in an internal static object and returns a pointer to that object.  Subsequent calls to ttyname()
     will modify the same object.

BSD
								   June 4, 1993 							       BSD

TTYNAME(3)						   BSD Library Functions Manual 						TTYNAME(3)

NAME

     ttyname, ttyname_r, isatty, ttyslot -- get name of associated terminal (tty) from file descriptor

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>

     char *
     ttyname(int fd);

     int
     ttyname_r(int fd, char *buf, size_t len);

     int
     isatty(int fd);

     #include <stdlib.h>

     int
     ttyslot(void);

DESCRIPTION

     These functions operate on the system file descriptors for terminal type devices.	These descriptors are not related to the standard I/O FILE
     typedef, but refer to the special device files found in /dev and named /dev/ttyxx and for which an entry exists in the initialization file
     /etc/ttys (see ttys(5)), or for pseudo-terminal devices created in ptyfs and named /dev/pts/n.

     The isatty() function determines if the file descriptor fd refers to a valid terminal type device.

     The ttyname() function gets the related device name of a file descriptor for which isatty() is true.  The ttyname_r() is the reentrant ver-
     sion of the above, and it places the results in buf.  If there is not enough space to place the results (indicated by len), then it returns
     an error.

     The ttyslot() function fetches the current process' control terminal number from the ttys(5) file entry.  If the terminal is a pseudo-termi-
     nal, and there is no special entry in the ttys(5) file for it, the slot number returned is 1 + (last slot number) + minor(tty).  This will
     return a consistent and unique number for each pseudo-terminal device without requiring one to enumerate all of them in ttys(5).

IMPLEMENTATION NOTES

     As an optimisation, these functions attempt to obtain information about all devices from the /var/run/dev.cdb database, if it exists.  If the
     database exists but is out of date, then these functions may produce incorrect results.  The database should be updated using the dev_mkdb(8)
     command.

RETURN VALUES

     The ttyname() function returns the NUL-terminated name if the device is found and isatty() is true; otherwise a NULL pointer is returned and
     errno is set to indicate the error.

     The ttyname_r() functions returns 0 on success and an error code on failure.

     The isatty() function returns 1 if fd is associated with a terminal device; otherwise it returns 0 and errno is set to indicate the error.

     The ttyslot() function returns the unit number of the device file if found; otherwise the value zero is returned.

FILES

     /dev/*
     /etc/ttys

ERRORS

     The ttyname(), ttyname_r(), and isatty() functions will fail if:

     [EBADF]		The fd argument is not a valid file descriptor.

     [ENOTTY]		The fd argument does not refer to a terminal device.

     The ttyname_r() function will also fail if:

     [ENOENT]		The terminal device is not found.  This can happen if the device node has been removed after it was opened.

     [ERANGE]		The buffer provided is not large enough to fit the result.

SEE ALSO

     ioctl(2), ttys(5), dev_mkdb(8)

STANDARDS

     The ttyname() and isatty() functions conform to ISO/IEC 9945-1:1990 (``POSIX.1'').

HISTORY

     isatty(), ttyname(), and ttyslot() functions appeared in Version 7 AT&T UNIX.

BUGS

     The ttyname() function leaves its result in an internal static object and returns a pointer to that object.  Subsequent calls to ttyname()
     will modify the same object.

BSD
								   June 1, 2012 							       BSD