REXEC(3)						     Linux Programmer's Manual							  REXEC(3)

NAME

       rexec - return stream to a remote command

SYNOPSIS

       #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);

DESCRIPTION

       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  get-
       servent(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.

CONFORMING TO

       Not in POSIX.1-2001.  Present on the BSDs, Solaris, and many other systems.  The rexec() function appeared in 4.2BSD.

BUGS

       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.

SEE ALSO

       rcmd(3), rexecd(8)

COLOPHON

       This page is part of release 3.27 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)