ttyslot(3) [osf1 man page]

ttyslot(3)						     Library Functions Manual							ttyslot(3)

NAME

       ttyslot - Finds the slot for the current user in the user accounting database

LIBRARY

       Standard C Library (libc.so, libc.a)

SYNOPSIS

       #include <stdlib.h>

       int ttyslot (void);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       ttyslot():  XSH4.2

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

DESCRIPTION

       The ttyslot() function returns the index of the current user's entry in the user accounting database.  The current user's entry is an entry
       for which the utline member matches the name of a terminal device associated with any of the process' file descriptors 0, 1, or 2 (standard
       input,  standard  output,  or  error output).  The index is an ordinal number representing the record number in the database of the current
       user's entry.  The first entry in the database is represented by the return value 0 (zero).

NOTES

       The ttyslot() function is scheduled to be withdrawn in a future version of the X/Open CAE Specification.

       [Tru64 UNIX]  When compiled in the X/Open UNIX environment, calls to the ttyslot() function are internally renamed by prepending _E to  the
       function  name. When you are debugging a module that includes the ttyslot() function and for which _XOPEN_SOURCE_EXTENDED has been defined,
       use _Ettyslot to refer to the ttyslot() call.  See standards(5) for information on when the _XOPEN_SOURCE_EXTENDED macro is defined.

RETURN VALUES

       Upon successful completion, the ttyslot() function returns the index of the current user's entry in the user accounting database.

       If an error is encountered while searching the database, or if none of the file descriptors 0, 1,  or  2  is  associated  with  a  terminal
       device, -1 is returned.

       The following behavior does not conform to the current standards, and is supported only for backward compatibility.

       [Tru64  UNIX]  In applications that are compiled in an environment that excludes the _XOPEN_SOURCE_EXTENDED standard definitions, the ttys-
       lot() function returns 0 (zero) on error.

RELATED INFORMATION

       Functions: getutxent(3), ttyname(3)

       Standards: standards(5) delim off

																	ttyslot(3)

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