Find the pathname of a terminal.
Format
#include <unixio.h> (Compatibility)
char *ttyname (void); (Compatibility)
#include <unistd.h> (OpenVMS V7.3-2 and higher)
char *ttyname (int filedes); (OpenVMS V7.3-2 and higher)
int ttyname_r (int filedes, char name, size_t
namesize); (OpenVMS V7.3-2 and higher),
(Integrity servers, Alpha)
1 – Arguments
filedes
An open file descriptor.
name
Pointer to a buffer in which the terminal name is stored.
namesize
The length of the buffer pointed to by the name argument.
2 – Description
The implementation of the ttyname function that takes no
argument is provided only for backward compatibility. This
legacy implementation returns a pointer to the null-terminated
name of the terminal device associated with file descriptor 0,
the default input device (stdin). A value of 0 is returned if
SYS$INPUT is not a TTY device.
The ttyname_r function and the implementation of ttyname that
takes a filedes argument are UNIX standard compliant and are
available with only OpenVMS Version 7.3-2 and higher.
The standard compliant ttyname function returns a pointer to a
string containing a null-terminated pathname of the terminal
associated with file descriptor filedes. The return value might
point to static data whose content is overwritten by each call.
The ttyname interface need not be reentrant.
The ttyname_r function returns a pointer to store the null-
terminated pathname of the terminal associated with the file
descriptor filedes in the character array referenced by name. The
array is namesize characters long and should have space for the
name and the terminating null character. The maximum length of
the terminal name is TTY_NAME_MAX.
If successful, ttyname returns a pointer to a string. Otherwise,
a NULL pointer is returned and errno is set to indicate the
error.
If successful, ttyname_r stores the terminal name as a null-
terminated string in the buffer pointed to by name and returns 0.
Otherwise, an error number is returned to indicate the error.
3 – Return Values
x Upon successful completion, ttyname returns a
pointer to a null-terminated string.
NULL Upon failure, ttyname returns a NULL pointer
and sets errno to indicate the failure:
o EBADF - The fildes argument is not a valid
file descriptor.
o ENOTTY - The fildes argument does not refer
to a terminal device.
0 Upon successful completion, ttyname_r returns
0.
n Upon failure, ttyname_r sets errno to indicate
the failure, and returns the same errno code:
o EBADF - The fildes argument is not a valid
file descriptor.
o ENOTTY - The fildes argument does not refer
to a TTY device.
o ERANGE - The value of namesize is smaller
than the length of the string to be
returned including the terminating null
character.
0 For the legacy ttyname, indicates that
SYS$INPUT is not a TTY device.