ptsname_r(2)                                               ptsname_r(2)

  ptsname()

  NAME

    ptsname(), ptsname_r() - get name of subordinate (slave) pseudo-terminal
    device

  SYNOPSIS

    #include 

    char * ptsname(int fildes)
    int ptsname_r (int filedes, char *buf, size_t len)

  DESCRIPTION

    The ptsname(2) call returns the name of a subordinate (also called slave)
    pty that corresponds to the master pseudo-terminal device indicated by
    fildes. This call is normally used after opening /dev/ptmx.

    The format of the subordinate name is /dev/tty[pqrs]0-9a-f].

    The ptsname_r(2) function is similar to ptsname(2) except that it places
    its result into the buffer identified by the buf argument, the length of
    which is specified by the len argument.

  RETURN VALUE

    On success, ptsname(2) returns a pointer to a string which is the name of
    the subordinate pseudo terminal. On failure, it returns NULL. (It fails if
    fildes can't be associated with the master side of a valid pseudo
    terminal.)

    On success, ptsname_r(2) returns zero; otherwise it returns nonzero.

  SEE ALSO

    grantpt(2)

    open(2)

    ttyname(2)

    unlockpt(2)

    pty(4)

    termios(4)

    tty(4)

  USAGE NOTES

    The ptsname_r function is thread safe. The ptsname function is not thread
    safe.

    None of these functions are async-signal safe.