1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)rexec.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd June 4, 1993 36.Dt REXEC 3 37.Os BSD 4.2 38.Sh NAME 39.Nm rexec 40.Nd return stream to a remote command 41.Sh SYNOPSIS 42.Ft int 43.Fn rexec "char **ahost" "int inport" "char *user" "char *passwd" "char *cmd" "int *fd2p" 44.Sh DESCRIPTION 45.Bf -symbolic 46This interface is obsoleted by 47.Xr rcmd 3 . 48It is available from the compatibility library, libcompat. 49.Ef 50.Pp 51The 52.Fn rexec 53function 54looks up the host 55.Fa *ahost 56using 57.Xr gethostbyname 3 , 58returning \-1 if the host does not exist. 59Otherwise 60.Fa *ahost 61is set to the standard name of the host. 62If a username and password are both specified, then these 63are used to authenticate to the foreign host; otherwise 64the environment and then the user's 65.Pa .netrc 66file in his 67home directory are searched for appropriate information. 68If all this fails, the user is prompted for the information. 69.Pp 70The port 71.Fa inport 72specifies which well-known 73.Tn DARPA 74Internet port to use for 75the connection; the call 76.Ql getservbyname(\\*qexec\\*q, \\*qtcp\\*q) 77(see 78.Xr getservent 3 ) 79will return a pointer to a structure, which contains the 80necessary port. 81The protocol for connection is described in detail in 82.Xr rexecd 8 . 83.Pp 84If the connection succeeds, 85a socket in the Internet domain of type 86.Dv SOCK_STREAM 87is returned to 88the caller, and given to the remote command as 89.Em stdin 90and 91.Em stdout . 92If 93.Fa fd2p 94is non-zero, then an auxiliary channel to a control 95process will be setup, and a descriptor for it will be placed 96in 97.Fa *fd2p . 98The control process will return diagnostic 99output from the command (unit 2) on this channel, and will also 100accept bytes on this channel as being 101.Tn UNIX 102signal numbers, to be 103forwarded to the process group of the command. The diagnostic 104information returned does not include remote authorization failure, 105as the secondary connection is set up after authorization has been 106verified. 107If 108.Fa fd2p 109is 0, then the 110.Em stderr 111(unit 2 of the remote 112command) will be made the same as the 113.Em stdout 114and no 115provision is made for sending arbitrary signals to the remote process, 116although you may be able to get its attention by using out-of-band data. 117.Sh SEE ALSO 118.Xr rcmd 3 , 119.Xr rexecd 8 120.Sh HISTORY 121The 122.Fn rexec 123function appeared in 124.Bx 4.2 . 125.Sh BUGS 126The 127.Fn rexec 128function sends the unencrypted password across the network. 129.Pp 130The underlying service is considered a big security hole and therefore 131not enabled on many sites, see 132.Xr rexecd 8 133for explanations. 134