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.\" 30.Dd June 4, 1993 31.Dt REXEC 3 32.Os 33.Sh NAME 34.Nm rexec 35.Nd return stream to a remote command 36.Sh LIBRARY 37.Lb libcompat 38.Sh SYNOPSIS 39.Ft int 40.Fn rexec "char **ahost" "int inport" "char *user" "char *passwd" "char *cmd" "int *fd2p" 41.Sh DESCRIPTION 42.Bf -symbolic 43This interface is obsoleted by 44.Xr rcmd 3 . 45.Ef 46.Pp 47The 48.Fn rexec 49function 50looks up the host 51.Fa *ahost 52using 53.Xr gethostbyname 3 , 54returning \-1 if the host does not exist. 55Otherwise 56.Fa *ahost 57is set to the standard name of the host. 58If a username and password are both specified, then these 59are used to authenticate to the foreign host; otherwise 60the environment and then the user's 61.Pa .netrc 62file in his 63home directory are searched for appropriate information. 64If all this fails, the user is prompted for the information. 65.Pp 66The port 67.Fa inport 68specifies which well-known 69.Tn DARPA 70Internet port to use for 71the connection; the call 72.Fn getservbyname \*qexec\*q \*qtcp\*q 73(see 74.Xr getservent 3 ) 75will return a pointer to a structure, which contains the 76necessary port. 77The protocol for connection is described in detail in 78.Xr rexecd 8 . 79.Pp 80If the connection succeeds, 81a socket in the Internet domain of type 82.Dv SOCK_STREAM 83is returned to 84the caller, and given to the remote command as 85.Dv stdin 86and 87.Dv stdout . 88If 89.Fa fd2p 90is non-zero, then an auxiliary channel to a control 91process will be setup, and a descriptor for it will be placed 92in 93.Fa *fd2p . 94The control process will return diagnostic 95output from the command (unit 2) on this channel, and will also 96accept bytes on this channel as being 97.Ux 98signal numbers, to be 99forwarded to the process group of the command. 100The diagnostic 101information returned does not include remote authorization failure, 102as the secondary connection is set up after authorization has been 103verified. 104If 105.Fa fd2p 106is 0, then the 107.Dv stderr 108(unit 2 of the remote 109command) will be made the same as the 110.Dv stdout 111and no 112provision is made for sending arbitrary signals to the remote process, 113although you may be able to get its attention by using out-of-band data. 114.Sh SEE ALSO 115.Xr rcmd 3 , 116.Xr rexecd 8 117.Sh HISTORY 118The 119.Fn rexec 120function appeared in 121.Bx 4.2 . 122.Sh BUGS 123The 124.Fn rexec 125function sends the unencrypted password across the network. 126.Pp 127The underlying service is considered a big security hole and therefore 128not enabled on many sites, see 129.Xr rexecd 8 130for explanations. 131