xref: /dragonfly/lib/libcompat/4.3/rexec.3 (revision abf903a5) 
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28.\"     @(#)rexec.3	8.1 (Berkeley) 6/4/93
29.\" $FreeBSD: src/lib/libcompat/4.3/rexec.3,v 1.5.2.4 2001/08/17 15:42:56 ru Exp $
30.\" $DragonFly: src/lib/libcompat/4.3/rexec.3,v 1.3 2007/07/30 22:11:33 swildner Exp $
31.\"
32.Dd June 4, 1993
33.Dt REXEC 3
34.Os
35.Sh NAME
36.Nm rexec
37.Nd return stream to a remote command
38.Sh LIBRARY
39.Lb libcompat
40.Sh SYNOPSIS
41.Ft int
42.Fn rexec "char **ahost" "int inport" "char *user" "char *passwd" "char *cmd" "int *fd2p"
43.Sh DESCRIPTION
44.Bf -symbolic
45This interface is obsoleted by
46.Xr rcmd 3 .
47.Ef
48.Pp
49The
50.Fn rexec
51function
52looks up the host
53.Fa *ahost
54using
55.Xr gethostbyname 3 ,
56returning \-1 if the host does not exist.
57Otherwise
58.Fa *ahost
59is set to the standard name of the host.
60If a username and password are both specified, then these
61are used to authenticate to the foreign host; otherwise
62the environment and then the user's
63.Pa .netrc
64file in his
65home directory are searched for appropriate information.
66If all this fails, the user is prompted for the information.
67.Pp
68The port
69.Fa inport
70specifies which well-known
71.Tn DARPA
72Internet port to use for
73the connection; the call
74.Fn getservbyname \*qexec\*q \*qtcp\*q
75(see
76.Xr getservent 3 )
77will return a pointer to a structure, which contains the
78necessary port.
79The protocol for connection is described in detail in
80.Xr rexecd 8 .
81.Pp
82If the connection succeeds,
83a socket in the Internet domain of type
84.Dv SOCK_STREAM
85is returned to
86the caller, and given to the remote command as
87.Em stdin
88and
89.Em stdout .
90If
91.Fa fd2p
92is non-zero, then an auxiliary channel to a control
93process will be setup, and a descriptor for it will be placed
94in
95.Fa *fd2p .
96The control process will return diagnostic
97output from the command (unit 2) on this channel, and will also
98accept bytes on this channel as being
99.Ux
100signal numbers, to be
101forwarded to the process group of the command.  The 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.Em stderr
109(unit 2 of the remote
110command) will be made the same as the
111.Em 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