TTYNAME(3C) Standard C Library Functions TTYNAME(3C)


NAME


ttyname, ttyname_r - find pathname of a terminal

SYNOPSIS


#include <unistd.h>

char *ttyname(int fildes);


char *ttyname_r(int fildes, char *name, int namelen);


Standard conforming


cc [ flag...] file ... -D_POSIX_PTHREAD_SEMANTICS [ library ... ]

int ttyname_r(int fildes, char *name, size_t namesize);


DESCRIPTION


The ttyname() function returns a pointer to a string containing the null-
terminated path name of the terminal device associated with file
descriptor fildes. The return value points to thread-specific data whose
content is overwritten by each call from the same thread.


The ttyname_r() function has the same functionality as ttyname() except
that the caller must supply a buffer name with length namelen to store
the result; this buffer must be at least _POSIX_PATH_MAX in size (defined
in <limits.h>). The standard-conforming version (see standards(5)) of
ttyname_r() takes a namesize parameter of type size_t.

RETURN VALUES


Upon successful completion, ttyname() and ttyname_r() return a pointer to
a string. Otherwise, a null pointer is returned and errno is set to
indicate the error.


The standard-conforming ttyname_r() returns 0 if successful or the error
number upon failure.

ERRORS


The ttyname() and ttyname_r() functions may fail if:

EBADF
The fildes argument is not a valid file descriptor. This
condition is reported.


ENOTTY
The fildes argument does not refer to a terminal device. This
condition is reported.


The ttyname_r() function may fail if:

ERANGE
The value of namesize is smaller than the length of the string
to be returned including the terminating null character.


ATTRIBUTES


See attributes(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | Safe |
+--------------------+-----------------+

SEE ALSO


Intro(3), gettext(3C), setlocale(3C), attributes(5), standards(5)

NOTES


When compiling multithreaded applications, see Intro(3), Notes On
Multithreaded Applications.


Messages printed from this function are in the native language specified
by the LC_MESSAGES locale category. See setlocale(3C).


The return value of ttyname() points to thread-specific data whose
content is overwritten by each call from the same thread. This function
is safe to use in multithreaded applications, but its use is discouraged.
The ttyname_r() function should used instead.


Solaris 2.4 and earlier releases provided definitions of the ttyname_r()
interface as specified in POSIX.1c Draft 6. The final POSIX.1c standard
changed the interface as described above. Support for the Draft 6
interface is provided for compatibility only and might not be supported
in future releases. New applications and libraries should use the
standard-conforming interface.


March 31, 2005 TTYNAME(3C)