ptsname.3c (2010 09)

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ptsname(3C) ptsname(3C)
NAME
ptsname() - get the pathname of a slave pty (pseudo-terminal)
SYNOPSIS
#include <stdlib.h>
char * ptsname (int fildes);
Obsolescent Interfaces
char * ptsname_r (int fildes, char *slavename, int len);
Remarks
ptsname() supports STREAMS pty (see ptm(7) and pts (7)), and non-STREAMS pty (see pty (7)) which
have different device naming conventions. Notice that the STREAMS pty, being an optional feature, is
supported only when it is installed on the system.
ptsname() is useful only on systems that follow the insf (1M) naming conventions for pty (STREAMS
and non-STREAMS).
DESCRIPTION
The passed parameter, fildes , is a file descriptor of an opened master pty.
ptsname() generates the
name of the slave pty corresponding to this master pty. This means that their minor numbers will be
identical.
Obsolescent Interfaces
ptsname_r() gets the pathname of a slave pty (pseudo-terminal).
RETURN VALUE
Upon successful completion,
ptsname() returns a string containing the full path name of a slave pty.
Otherwise, a NULL pointer is returned. The return value is pointed to static data area which is overwrit-
ten with each call to ptsname(), so it should be copied if it is to be saved.
ERRORS
ptsname() fails and returns a NULL pointer under the following conditions:
• File descriptor does not refer to an open master pty.
• Request falls outside pty name-space.
• Pty device naming conventions have not been followed.
•
ptsname() failed to find a match.
WARNINGS
ptsname_r() is obsolescent interface supported only for compatibility with existing DCE applications.
New multi-threaded applications should use
ptsname().
EXAMPLES
The following example shows how
ptsname() is typically used for non-STREAMS pty to obtain the
pathname of the slave pty corresponding to a master pty obtained through a pty clone open.
int fd_master;
char *path;
...
fd_master = open("/dev/ptym/clone", O_RDONLY);
path = ptsname(fd_master);
The following example shows how ptsname() is typically used on obtaining the pathname of the
STREAMS slave pty corresponding to a STREAMS master pty.
int fd_master, fd_slave;
char *slave;
...
fd_master = open("/dev/ptmx", O_RDWR);
grantpt(fd_master);
unlockpt(fd_master);
slave = ptsname(fd_master);
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1