systemd/man/sd_bus_message_append_basic.3
2015-02-17 11:22:16 +01:00

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'\" t
.TH "SD_BUS_MESSAGE_APPEND_BASIC" "3" "" "systemd 219" "sd_bus_message_append_basic"
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.SH "NAME"
sd_bus_message_append_basic \- Attach a single part to a message
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <systemd/sd\-bus\&.h>
.fi
.ft
.HP \w'int\ sd_bus_message_append_basic('u
.BI "int sd_bus_message_append_basic(sd_bus_message\ *" "m" ", char\ " "type" ", char\ void\ *" "p" ");"
.SH "DESCRIPTION"
.PP
\fBsd_bus_message_append_basic\fR
appends a single item to the message
\fIm\fR\&. Parameter
\fItype\fR
determines how pointer
\fIp\fR
is interpreted\&.
\fItype\fR
must be one of the basic types as defined by the
\m[blue]\fBBasic Types\fR\m[]\&\s-2\u[1]\d\s+2
section of the D\-Bus specification, and listed in the table below\&.
.sp
.it 1 an-trap
.nr an-no-space-flag 1
.nr an-break-flag 1
.br
.B Table\ \&1.\ \&Item format specifiers
.TS
allbox tab(:);
lB lB lB lB.
T{
Specifier
T}:T{
Constant
T}:T{
Description
T}:T{
Size
T}
.T&
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l l l l.
T{
"y"
T}:T{
\fBSD_BUS_TYPE_BYTE\fR
T}:T{
unsigned integer
T}:T{
1 byte
T}
T{
"b"
T}:T{
\fBSD_BUS_TYPE_BOOLEAN\fR
T}:T{
boolean
T}:T{
4 bytes
T}
T{
"n"
T}:T{
\fBSD_BUS_TYPE_INT16\fR
T}:T{
signed integer
T}:T{
2 bytes
T}
T{
"q"
T}:T{
\fBSD_BUS_TYPE_UINT16\fR
T}:T{
unsigned integer
T}:T{
2 bytes
T}
T{
"i"
T}:T{
\fBSD_BUS_TYPE_INT32\fR
T}:T{
signed integer
T}:T{
4 bytes
T}
T{
"u"
T}:T{
\fBSD_BUS_TYPE_UINT32\fR
T}:T{
unsigned integer
T}:T{
4 bytes
T}
T{
"x"
T}:T{
\fBSD_BUS_TYPE_INT64\fR
T}:T{
signed integer
T}:T{
8 bytes
T}
T{
"t"
T}:T{
\fBSD_BUS_TYPE_UINT64\fR
T}:T{
unsigned integer
T}:T{
8 bytes
T}
T{
"d"
T}:T{
\fBSD_BUS_TYPE_DOUBLE\fR
T}:T{
floating\-point
T}:T{
8 bytes
T}
T{
"s"
T}:T{
\fBSD_BUS_TYPE_STRING\fR
T}:T{
Unicode string
T}:T{
variable
T}
T{
"o"
T}:T{
\fBSD_BUS_TYPE_OBJECT_PATH\fR
T}:T{
object path
T}:T{
variable
T}
T{
"g"
T}:T{
\fBSD_BUS_TYPE_SIGNATURE\fR
T}:T{
signature
T}:T{
variable
T}
T{
"h"
T}:T{
\fBSD_BUS_TYPE_UNIX_FD\fR
T}:T{
UNIX file descriptor
T}:T{
4 bytes
T}
.TE
.sp 1
.PP
The value of the parameter is copied into the memory area containing the message and may be changed after this call\&. If
\fItype\fR
is
"h"
(UNIX file descriptor), it is always "consumed" by this call, and either successfully appended to the message or closed\&.
.PP
For types
"s",
"o", and
"g", the parameter
\fIp\fR
is interpreted as a pointer to a
\fBNUL\fR\-terminated character sequence\&. As a special case, a
\fBNULL\fR
pointer is interpreted as an empty string\&. The string should be valid Unicode string encoded as UTF\-8\&. In case of the two latter types, the additional requirements for a D\-Bus object path or type signature should be satisfied\&. Those requirements should be verified by the recipient of the message\&.
.SH "RETURN VALUE"
.PP
On success, this call returns 0 or a positive integer\&. On failure, it returns a negative errno\-style error code\&.
.SH "ERRORS"
.PP
Returned errors may indicate the following problems:
.PP
\fB\-EINVAL\fR
.RS 4
Specified parameter is invalid\&.
.RE
.PP
\fB\-EPERM\fR
.RS 4
Message has been sealed\&.
.RE
.PP
\fB\-ESTALE\fR
.RS 4
Message is in invalid state\&.
.RE
.PP
\fB\-ENXIO\fR
.RS 4
Message cannot be appended to\&.
.RE
.PP
\fB\-ENOMEM\fR
.RS 4
Memory allocation failed\&.
.RE
.SH "NOTES"
.PP
The
\fBsd_bus_append_basic()\fR
function described here is available as a shared library, which can be compiled and linked to with the
\fBlibsystemd\fR\ \&\fBpkg-config\fR(1)
file\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1),
\fBsd-bus\fR(3),
\fBsd_bus_message_append\fR(3),
\m[blue]\fBThe D\-Bus specification\fR\m[]\&\s-2\u[2]\d\s+2
.SH "NOTES"
.IP " 1." 4
Basic Types
.RS 4
\%http://dbus.freedesktop.org/doc/dbus-specification.html#basic-types
.RE
.IP " 2." 4
The D-Bus specification
.RS 4
\%http://dbus.freedesktop.org/doc/dbus-specification.html
.RE