REXEC(3) Library Functions Manual REXEC(3)
rexec -- return stream to a remote command
Compatibility Library (libcompat, -lcompat)
rexec(char **ahost, int inport, char *user, char *passwd, char *cmd, int
This interface is obsoleted by rcmd(3). It is available from the
compatibility library, libcompat.
The rexec() function looks up the host *ahost using gethostbyname(3),
returning -1 if the host does not exist. Otherwise *ahost is set to the
standard name of the host. If a username and password are both
specified, then these are used to authenticate to the foreign host;
otherwise the environment and then the user's .netrc file in his home
directory are searched for appropriate information. If all this fails,
the user is prompted for the information.
The port inport specifies which well-known DARPA Internet port to use for
the connection; the call `getservbyname(*qexec*q, *qtcp*q)' (see
getservent(3)) will return a pointer to a structure, which contains the
necessary port. The protocol for connection is described in detail in
If the connection succeeds, a socket in the Internet domain of type
SOCK_STREAM is returned to the caller, and given to the remote command as
stdin and stdout. If fd2p is non-zero, then an auxiliary channel to a
control process will be set up, and a descriptor for it will be placed in
*fd2p. The control process will return diagnostic output from the
command (unit 2) on this channel, and will also accept bytes on this
channel as being UNIX signal numbers, to be forwarded to the process
group of the command. The diagnostic information returned does not
include remote authorization failure, as the secondary connection is set
up after authorization has been verified. If fd2p is 0, then the stderr
(unit 2 of the remote command) will be made the same as the stdout and no
provision is made for sending arbitrary signals to the remote process,
although you may be able to get its attention by using out-of-band data.
The rexec() function appeared in 4.2BSD.
NetBSD 6.1.5 June 4, 1993 NetBSD 6.1.5