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
|
'\" t
.TH "SD_BUS_MESSAGE_NEW_SIGNAL" "3" "" "systemd 241" "sd_bus_message_new_signal"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
sd_bus_message_new_signal \- Create a signal message
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <systemd/sd\-bus\&.h>
.fi
.ft
.HP \w'int\ sd_bus_message_new_signal('u
.BI "int sd_bus_message_new_signal(sd_bus\ *" "bus" ", sd_bus_message\ **" "m" ", const\ char\ *" "path" ", const\ char\ *" "interface" ", const\ char\ *" "member" ");"
.SH "DESCRIPTION"
.PP
The
\fBsd_bus_message_new_signal()\fR
function creates a new bus message object that encapsulates a D\-Bus signal, and returns it in the
\fIm\fR
output parameter\&. The signal will be sent to path
\fIpath\fR, on the interface
\fIinterface\fR, member
\fImember\fR\&. When this message is sent, no reply is expected\&. See
\fBsd_bus_message_new_call\fR(1)
for a short description of the meaning of the
\fIpath\fR,
\fIinterface\fR, and
\fImember\fR
parameters\&.
.SH "RETURN VALUE"
.PP
This function returns 0 if the message object was successfully created, and a negative errno\-style error code otherwise\&.
.SH "ERRORS"
.PP
Returned errors may indicate the following problems:
.PP
\fB\-EINVAL\fR
.RS 4
The output parameter
\fIm\fR
is
\fBNULL\fR\&.
.sp
The
\fIpath\fR
parameter is not a valid D\-Bus path ("/an/object/path"), the
\fIinterface\fR
parameter is not a valid D\-Bus interface name ("an\&.interface\&.name"), or the
\fImember\fR
parameter is not a valid D\-Bus member ("Name")\&.
.RE
.PP
\fB\-ENOTCONN\fR
.RS 4
The bus parameter
\fIbus\fR
is
\fBNULL\fR
or the bus is not connected\&.
.RE
.PP
\fB\-ENOMEM\fR
.RS 4
Memory allocation failed\&.
.RE
.SH "NOTES"
.PP
These APIs are implemented as a shared library, which can be compiled and linked to with the
\fBlibsystemd\fR\ \&\fBpkg-config\fR(1)
file\&.
.SH "EXAMPLES"
.PP
\fBExample\ \&1.\ \&Send a simple signal\fR
.sp
.if n \{\
.RS 4
.\}
.nf
#include <systemd/sd\-bus\&.h>
#define _cleanup_(f) __attribute__((cleanup(f)))
int send_unit_files_changed(sd_bus *bus) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *message = NULL;
int r;
r = sd_bus_message_new_signal(bus, &message,
"/org/freedesktop/systemd1",
"org\&.freedesktop\&.systemd1\&.Manager",
"UnitFilesChanged");
if (r < 0)
return r;
return sd_bus_send(bus, message, NULL);
}
.fi
.if n \{\
.RE
.\}
.PP
This function in systemd sources is used to emit the
"UnitFilesChanged"
signal when the unit files have been changed\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1),
\fBsd-bus\fR(3)
|
