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.Dd June 4, 1993 29.Dt REXEC 3 30.Os 31.Sh NAME 32.Nm rexec 33.Nd return stream to a remote command 34.Sh LIBRARY 35.Lb libcompat 36.Sh SYNOPSIS 37.Ft int 38.Fn rexec "char **ahost" "int inport" "char *user" "char *passwd" "char *cmd" "int *fd2p" 39.Sh DESCRIPTION 40.Bf -symbolic 41This interface is obsoleted by 42.Xr rcmd 3 . 43.Ef 44.Pp 45The 46.Fn rexec 47function 48looks up the host 49.Fa *ahost 50using 51.Xr gethostbyname 3 , 52returning \-1 if the host does not exist. 53Otherwise 54.Fa *ahost 55is set to the standard name of the host. 56If a username and password are both specified, then these 57are used to authenticate to the foreign host; otherwise 58the environment and then the user's 59.Pa .netrc 60file in his 61home directory are searched for appropriate information. 62If all this fails, the user is prompted for the information. 63.Pp 64The port 65.Fa inport 66specifies which well-known 67.Tn DARPA 68Internet port to use for 69the connection; the call 70.Fn getservbyname \*qexec\*q \*qtcp\*q 71(see 72.Xr getservent 3 ) 73will return a pointer to a structure, which contains the 74necessary port. 75The protocol for connection is described in detail in 76.Xr rexecd 8 . 77.Pp 78If the connection succeeds, 79a socket in the Internet domain of type 80.Dv SOCK_STREAM 81is returned to 82the caller, and given to the remote command as 83.Dv stdin 84and 85.Dv stdout . 86If 87.Fa fd2p 88is non-zero, then an auxiliary channel to a control 89process will be setup, and a descriptor for it will be placed 90in 91.Fa *fd2p . 92The control process will return diagnostic 93output from the command (unit 2) on this channel, and will also 94accept bytes on this channel as being 95.Ux 96signal numbers, to be 97forwarded to the process group of the command. 98The diagnostic 99information returned does not include remote authorization failure, 100as the secondary connection is set up after authorization has been 101verified. 102If 103.Fa fd2p 104is 0, then the 105.Dv stderr 106(unit 2 of the remote 107command) will be made the same as the 108.Dv stdout 109and no 110provision is made for sending arbitrary signals to the remote process, 111although you may be able to get its attention by using out-of-band data. 112.Sh SEE ALSO 113.Xr rcmd 3 , 114.Xr rexecd 8 115.Sh HISTORY 116The 117.Fn rexec 118function appeared in 119.Bx 4.2 . 120.Sh BUGS 121The 122.Fn rexec 123function sends the unencrypted password across the network. 124.Pp 125The underlying service is considered a big security hole and therefore 126not enabled on many sites, see 127.Xr rexecd 8 128for explanations. 129