NAME
sd_bus_message_append_basic - Attach a single field to a messageSYNOPSIS
#include <systemd/sd-bus.h>
int
sd_bus_message_append_basic(sd_bus_message *m,
char type,
const void *p);
DESCRIPTION
sd_bus_message_append_basic() appends a single field to the message m. The parameter type determines how the pointer p is interpreted. type must be one of the basic types as defined by the Basic Types[1] section of the D-Bus specification, and listed in the table below.Specifier | Constant | Description | Size | Expected C Type |
"y" | SD_BUS_TYPE_BYTE | unsigned integer | 1 byte | uint8_t |
"b" | SD_BUS_TYPE_BOOLEAN | boolean | 4 bytes | int |
"n" | SD_BUS_TYPE_INT16 | signed integer | 2 bytes | int16_t |
"q" | SD_BUS_TYPE_UINT16 | unsigned integer | 2 bytes | uint16_t |
"i" | SD_BUS_TYPE_INT32 | signed integer | 4 bytes | int32_t |
"u" | SD_BUS_TYPE_UINT32 | unsigned integer | 4 bytes | uint32_t |
"x" | SD_BUS_TYPE_INT64 | signed integer | 8 bytes | int64_t |
"t" | SD_BUS_TYPE_UINT64 | unsigned integer | 8 bytes | uint64_t |
"d" | SD_BUS_TYPE_DOUBLE | floating-point | 8 bytes | double |
"s" | SD_BUS_TYPE_STRING | Unicode string | variable | char[] |
"o" | SD_BUS_TYPE_OBJECT_PATH | object path | variable | char[] |
"g" | SD_BUS_TYPE_SIGNATURE | signature | variable | char[] |
"h" | SD_BUS_TYPE_UNIX_FD | UNIX file descriptor | 4 bytes | int |
RETURN VALUE
On success, this call returns 0 or a positive integer. On failure, it returns a negative errno-style error code.Errors
Returned errors may indicate the following problems: -EINVALSpecified parameter is invalid.
-EPERM
Message has been sealed.
-ESTALE
Message is in invalid state.
-ENXIO
Message cannot be appended to.
-ENOMEM
Memory allocation failed.
NOTES
These APIs are implemented as a shared library, which can be compiled and linked to with the libsystemd pkg-config(1) file.SEE ALSO
systemd(1), sd-bus(3), sd_bus_message_read_basic(3), sd_bus_message_append(3), The D-Bus specification[2]NOTES
- 1.
- Basic Types
- 2.
- The D-Bus specification
systemd 252 |