1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
.\" Copyright (c) 1999 Berkeley Software Design, Inc. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Berkeley Software Design Inc's name may not be used to endorse or
.\" promote products derived from this software without specific prior
.\" written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd September 13, 2013
.Dt DAEMON 8
.Os
.Sh NAME
.Nm daemon
.Nd run detached from the controlling terminal
.Sh SYNOPSIS
.Nm
.Op Fl cfr
.Op Fl p Ar child_pidfile
.Op Fl P Ar supervisor_pidfile
.Op Fl u Ar user
.Ar command arguments ...
.Sh DESCRIPTION
The
.Nm
utility detaches itself from the controlling terminal and
executes the program specified by its arguments.
Privileges may be lowered to the specified user.
.Pp
The options are as follows:
.Bl -tag -width indent
.It Fl c
Change the current working directory to the root
.Pq Dq Pa / .
.It Fl f
Redirect standard input, standard output and standard error to
.Pa /dev/null .
.It Fl p Ar child_pidfile
Write the ID of the created process into the
.Ar child_pidfile
using the
.Xr pidfile 3
functionality.
The program is executed in a spawned child process while the
.Nm
waits until it terminates to keep the
.Ar child_pidfile
locked and removes it after the process exits.
The
.Ar child_pidfile
owner is the user who runs the
.Nm
regardless of whether the
.Fl u
option is used or not.
.It Fl P Ar supervisor_pidfile
Write the ID of the
.Nm
process into the
.Ar supervisor_pidfile
using the
.Xr pidfile 3
functionality.
The program is executed in a spawned child process while the
.Nm
waits until it terminates to keep the
.Ar supervisor_pidfile
locked and removes it after the process exits.
The
.Ar supervisor_pidfile
owner is the user who runs the
.Nm
regardless of whether the
.Fl u
option is used or not.
.It Fl r
Supervise and restart the program if it has been terminated.
.It Fl u Ar user
Login name of the user to execute the program under.
Requires adequate superuser privileges.
.El
.Pp
If the
.Fl p ,
.Fl P
or
.Fl r
option is specified the program is executed in a spawned child process.
The
.Nm
waits until it terminates to keep the pid file(s) locked and removes them
after the process exits or restarts the program.
In this case if the monitoring
.Nm
receives software termination signal (SIGTERM) it forwards it to the
spawned process.
Normally it will cause the child to exit, remove the pidfile(s)
and then terminate.
.Pp
The
.Fl P
option is useful combined with the
.Fl r
option as
.Ar supervisor_pidfile
contains the ID of the supervisor
not the child. This is especially important if you use
.Fl r
in an rc script as the
.Fl p
option will give you the child's ID to signal when you attempt to
stop the service, causing
.Nm
to restart the child.
.Sh EXIT STATUS
The
.Nm
utility exits 1 if an error is returned by the
.Xr daemon 3
library routine, 2 if
.Ar child_pidfile
or
.Ar supervisor_pidfile
is requested, but cannot be opened, 3 if process is already running (pidfile
exists and is locked),
otherwise 0.
.Sh DIAGNOSTICS
If the command cannot be executed, an error message is displayed on
standard error unless the
.Fl f
flag is specified.
.Sh SEE ALSO
.Xr setregid 2 ,
.Xr setreuid 2 ,
.Xr daemon 3 ,
.Xr exec 3 ,
.Xr pidfile 3 ,
.Xr termios 4 ,
.Xr tty 4
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 4.7 .
|
