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: src/lib/libcompat/4.3/rexec.3,v 1.5.2.4 2001/08/17 15:42:56 ru Exp $ 34.\" 35.Dd June 4, 1993 36.Dt REXEC 3 37.Os 38.Sh NAME 39.Nm rexec 40.Nd return stream to a remote command 41.Sh LIBRARY 42.Lb libcompat 43.Sh SYNOPSIS 44.Ft int 45.Fn rexec "char **ahost" "int inport" "char *user" "char *passwd" "char *cmd" "int *fd2p" 46.Sh DESCRIPTION 47.Bf -symbolic 48This interface is obsoleted by 49.Xr rcmd 3 . 50.Ef 51.Pp 52The 53.Fn rexec 54function 55looks up the host 56.Fa *ahost 57using 58.Xr gethostbyname 3 , 59returning \-1 if the host does not exist. 60Otherwise 61.Fa *ahost 62is set to the standard name of the host. 63If a username and password are both specified, then these 64are used to authenticate to the foreign host; otherwise 65the environment and then the user's 66.Pa .netrc 67file in his 68home directory are searched for appropriate information. 69If all this fails, the user is prompted for the information. 70.Pp 71The port 72.Fa inport 73specifies which well-known 74.Tn DARPA 75Internet port to use for 76the connection; the call 77.Fn getservbyname \*qexec\*q \*qtcp\*q 78(see 79.Xr getservent 3 ) 80will return a pointer to a structure, which contains the 81necessary port. 82The protocol for connection is described in detail in 83.Xr rexecd 8 . 84.Pp 85If the connection succeeds, 86a socket in the Internet domain of type 87.Dv SOCK_STREAM 88is returned to 89the caller, and given to the remote command as 90.Em stdin 91and 92.Em stdout . 93If 94.Fa fd2p 95is non-zero, then an auxiliary channel to a control 96process will be setup, and a descriptor for it will be placed 97in 98.Fa *fd2p . 99The control process will return diagnostic 100output from the command (unit 2) on this channel, and will also 101accept bytes on this channel as being 102.Tn UNIX 103signal numbers, to be 104forwarded to the process group of the command. The diagnostic 105information returned does not include remote authorization failure, 106as the secondary connection is set up after authorization has been 107verified. 108If 109.Fa fd2p 110is 0, then the 111.Em stderr 112(unit 2 of the remote 113command) will be made the same as the 114.Em stdout 115and no 116provision is made for sending arbitrary signals to the remote process, 117although you may be able to get its attention by using out-of-band data. 118.Sh SEE ALSO 119.Xr rcmd 3 , 120.Xr rexecd 8 121.Sh HISTORY 122The 123.Fn rexec 124function appeared in 125.Bx 4.2 . 126.Sh BUGS 127The 128.Fn rexec 129function sends the unencrypted password across the network. 130.Pp 131The underlying service is considered a big security hole and therefore 132not enabled on many sites, see 133.Xr rexecd 8 134for explanations. 135