| NAME | SYNOPSIS | DESCRIPTION | CONFORMING TO | BUGS | SEE ALSO | COLOPHON | The Linux Programming Interface |
REXEC(3) Linux Programmer's Manual REXEC(3)
rexec - return stream to a remote command
#define _BSD_SOURCE /* See feature_test_macros(7) */
#include <netdb.h>
int rexec(char **ahost, int inport, char *user,
char *passwd, char *cmd, int *fd2p);
This interface is obsoleted by rcmd(3).
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 that 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 nonzero, then an auxiliary channel to a control
process will be setup, 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.
Not in POSIX.1-2001. Present on the BSDs, Solaris, and many other systems.
The rexec() function appeared in 4.2BSD.
The rexec() function sends the unencrypted password across the network.
The underlying service is considered a big security hole and therefore not
enabled on many sites, see rexecd(8) for explanations.
rcmd(3), rexecd(8)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2010-09-10 REXEC(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface