NAME
rexec —
return stream to a remote
command
LIBRARY
Compatibility Library (libcompat, -lcompat)
SYNOPSIS
int
rexec(
char
**ahost,
int inport,
char *user,
char *passwd,
char *cmd,
int *fd2p);
DESCRIPTION
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
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
rcmd(3),
rexecd(8)
HISTORY
The
rexec() function appeared in
4.2BSD.