NAME

ttyname, isatty − find name of a terminal

SYNOPSIS

char ∗ttyname (fildes)
int fildes;

int isatty (fildes)
int fildes;

DESCRIPTION

ttyname returns a pointer to a string containing the null-terminated path name of the terminal device associated with file descriptor fildes.

Isatty returns 1 if fildes is associated with a terminal device, 0 otherwise. 

FILES

/dev/∗

DIAGNOSTICS

ttyname returns a NULL pointer if fildes does not describe a terminal device in directory /dev. 

If isatty returns 0, errno will be set to indicate the reason:

[EBADF] the fildes argument is not a valid open file descriptor, or

[ENOTTY] the fildes argument is not associated with a terminal. 

NOTES

The return value of ttyname points to static data whose content is overwritten by each call. 

CX/UX Programmer’s Reference Manual