ttyslot(3C)
find the slot in the utmp file of the current user
From the original Amiga UNIX 2.1 manual. Some things it mentions may not be in this release.
NAME
ttyslot - find the slot in the utmp file of the current user
SYNOPSIS
#include <stdlib.h> int ttyslot (void);
DESCRIPTION
ttyslot returns the index of the current user's entry in the /var/adm/utmp file. The returned index is accomplished by scanning files in /dev for the name of the terminal associated with the standard input, the standard output, or the standard error output (0, 1, or 2).
FILES
/var/adm/utmp
SEE ALSO
getut(3C), ttyname(3C).
DIAGNOSTICS
A value of -1 is returned if an error was encountered while searching for the terminal name or if none of the above file descriptors are associated with a terminal device.