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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 num-
     ber 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

Mac OS X 10.8 - Generated Fri Aug 31 16:25:54 CDT 2012
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