| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | NOTES | SEE ALSO | COLOPHON |  | 
TTYNAME(3)                Linux Programmer's Manual               TTYNAME(3)
       ttyname, ttyname_r - return name of a terminal
       #include <unistd.h>
       char *ttyname(int fd);
       int ttyname_r(int fd, char *buf, size_t buflen);
       The function ttyname() returns a pointer to the null-terminated
       pathname of the terminal device that is open on the file descriptor
       fd, or NULL on error (for example, if fd is not connected to a
       terminal).  The return value may point to static data, possibly
       overwritten by the next call.  The function ttyname_r() stores this
       pathname in the buffer buf of length buflen.
       The function ttyname() returns a pointer to a pathname on success.
       On error, NULL is returned, and errno is set appropriately.  The
       function ttyname_r() returns 0 on success, and an error number upon
       error.
       EBADF  Bad file descriptor.
       ENOTTY File descriptor does not refer to a terminal device.
       ERANGE (ttyname_r()) buflen was too small to allow storing the
              pathname.
       ENODEV File descriptor refers to a slave pseudoterminal device but
              the corresponding pathname could not be found (see NOTES).
       For an explanation of the terms used in this section, see
       attributes(7).
       ┌────────────┬───────────────┬────────────────────────┐
       │Interface   │ Attribute     │ Value                  │
       ├────────────┼───────────────┼────────────────────────┤
       │ttyname()   │ Thread safety │ MT-Unsafe race:ttyname │
       ├────────────┼───────────────┼────────────────────────┤
       │ttyname_r() │ Thread safety │ MT-Safe                │
       └────────────┴───────────────┴────────────────────────┘
       POSIX.1-2001, POSIX.1-2008, 4.2BSD.
       A process that keeps a file descriptor that refers to a pts(4) device
       open when switching to another mount namespace that uses a different
       /dev/ptmx instance may still accidentally find that a device path of
       the same name for that file descriptor exists.  However, this device
       path refers to a different device and thus can't be used to access
       the device that the file descriptor refers to.  Calling ttyname() or
       ttyname_r() on the file descriptor in the new mount namespace will
       cause these functions to return NULL and set errno to ENODEV.
       tty(1), fstat(2), ctermid(3), isatty(3), pts(4)
       This page is part of release 4.15 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.
Linux                            2017-05-03                       TTYNAME(3)
Pages that refer to this page: ctermid(3), getttyent(3), getutent(3), isatty(3), openpty(3), ptsname(3), ttyslot(3)
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