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 overwritten 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);
fd_slave = open(slave, O_RDWR);
ioctl(fd_slave, I_PUSH, "ptem");
ioctl(fd_slave, I_PUSH, "ldterm");
AUTHOR
ptsname()
and
ptsname_r()
were developed by HP and OSF.
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