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