systemd A monkey with a typewriter Zbigniew Jędrzejewski-Szmek zbyszek@in.waw.pl sd_bus_message_append_basic 3 sd_bus_message_append_basic Attach a single part to a message #include <systemd/sd-bus.h> int sd_bus_message_append_basic sd_bus_message *m char type char void *p sd_bus_message_append_basic appends a single item to the message m. Parameter type determines how pointer p is interpreted. type must be one of the basic types as defined by the Basic Types section of the D-Bus specification, and listed in the table below. Specifier Constant Description Size y SD_BUS_TYPE_BYTE unsigned integer 1 byte b SD_BUS_TYPE_BOOLEAN boolean 4 bytes n SD_BUS_TYPE_INT16 signed integer 2 bytes q SD_BUS_TYPE_UINT16 unsigned integer 2 bytes i SD_BUS_TYPE_INT32 signed integer 4 bytes u SD_BUS_TYPE_UINT32 unsigned integer 4 bytes x SD_BUS_TYPE_INT64 signed integer 8 bytes t SD_BUS_TYPE_UINT64 unsigned integer 8 bytes d SD_BUS_TYPE_DOUBLE floating-point 8 bytes s SD_BUS_TYPE_STRING Unicode string variable o SD_BUS_TYPE_OBJECT_PATH object path variable g SD_BUS_TYPE_SIGNATURE signature variable h SD_BUS_TYPE_UNIX_FD UNIX file descriptor 4 bytes The value of the parameter is copied into the memory area containing the message and may be changed after this call. If type is h (UNIX file descriptor), it is always "consumed" by this call, and either successfully appended to the message or closed. For types s, o, and g, the parameter p is interpreted as a pointer to a NUL-terminated character sequence. As a special case, a NULL 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. On success, this call returns 0 or a positive integer. On failure, it returns a negative errno-style error code. Returned errors may indicate the following problems: -EINVAL Specified parameter is invalid. -EPERM Message has been sealed. -ESTALE Message is in invalid state. -ENXIO Message cannot be appended to. -ENOMEM Memory allocation failed. The sd_bus_append_basic() function described here is available as a shared library, which can be compiled and linked to with the libsystemd pkg-config1 file. systemd1, sd-bus3, sd_bus_message_append3, The D-Bus specification