HP-UX Reference (11i v1 00/12) - 3 Library Functions N-Z (vol 7)
__________________________________________________________________________________________________________________________________________________________________________________________________
__________________________________________________________________________________________________________________________________________________________________________________________________
STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man3/nan.3m
________________________________________________________________
___ ___
r
rcmd(3N) rcmd(3N)
IPPORT_RESERVED−1 are exhausted.
If the call succeeds, the socket descriptor is returned to the caller and the port number is returned in the
location pointed to by port. If the call fails, −1 is returned to the caller.
The socket returned by rresvport() has the SO_KEEPALIVE option on.
Only the superuser is permitted to bind a privileged address to a socket. Therefore, any program using
rresvport() must be run as superuser.
ruserok()
The ruserok() function is used by servers to authenticate clients requesting service with rcmd().
ruserok() verifies that ruser on rhost is authorized to act as luser on the local host.
superuser is an integer flag that should be nonzero if the local user name corresponds to a superuser. If the
superuser flag is not set, ruserok() first checks the file /etc/hosts.equiv to authenticate the
request for service. If this check succeeds, ruserok() returns 0. If the superuser flag is set, or if there
is no file /etc/hosts.equiv, or if the check fails, ruserok() then checks the file .rhosts (if there
is one) in the local user’s home directory. ruserok() returns 0 if this check succeeds. Otherwise, it
returns −1.
Typically, the file
/etc/hosts.equiv
contains a list of host names, and users’ .rhosts
files contain
host-name/user-name pairs. A remote user is authenticated by
ruserok() if the remote host name
appears in
/etc/hosts.equiv
and the remote user name and local user name are the same, or if the
remote host name and the remote user name appear together in
.rhosts in the home directory of the
local user.
For a complete explanation of the syntax understood by ruserok(), see hosts.equiv(4).
MULTITHREADED USAGE
Thread Safe: Yes
Cancel Safe: Yes
Async-cancel Safe: No
Async-signal Safe: No
These functions can be called safely in a multithreaded environment. They may be cancellation points in
that they call functions that are cancellation points.
DIAGNOSTICS
rcmd() Diagnostic Messages
rcmd() generates the following diagnostic messages.
hostname: Unknown host
gethostbyname was unable to find an entry in the hosts database matching the name of the
server (see gethostent(3N) and hosts(4)).
Next step: Have the system administrator of your host check whether the remote host’s entry is
in the hosts database (see hosts(4)).
connect: hostname: ...
Unable to establish a connection to the reserved port. A message that specifies the reason for
the failure is appended to this diagnostic message.
write: Setting up stderr
Error writing to the socket connection set up for error message transmission.
system call: ...
Error executing the system call. Appended to this error is a message specifying the reason for
the failure.
socket: Protocol failure in circuit setup
Socket connection not established on a reserved port or socket address not of the Internet family
type.
read: hostname: ...
Section 3−−746 − 2 − HP-UX Release 11i: December 2000
___
___