NAME
rexec —
return stream to a remote
command
LIBRARY
library “libcompat”
SYNOPSIS
int
rexec(char
**ahost, int
inport, char *user,
char *passwd,
char *cmd,
int *fd2p);
DESCRIPTION
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("exec",
"tcp")’ (see
getservent(3)) will return a pointer to a structure, which
contains the necessary port. The protocol for connection is described in
detail in rexecd(8).
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.
SEE ALSO
HISTORY
The rexec() function appeared in
4.2BSD.