systemd sd_bus_message_append_string_memfd 3 sd_bus_message_append_string_memfd sd_bus_message_append_string_iovec sd_bus_message_append_string_space Attach a string to a message #include <systemd/sd-bus.h> int sd_bus_message_append_string_memfd sd_bus_message *m int memfd int sd_bus_message_append_string_iovec sd_bus_message *m const struct iovec *iov unsigned n int sd_bus_message_append_string_space sd_bus_message *m size_t size char **s The functions sd_bus_message_append_string_memfd() and sd_bus_message_append_string_iovec() can be used to append a single string (item of type s) to message m. In case of sd_bus_message_append_string_memfd(), the contents of memfd are the string. They must satisfy the same constraints as described for the s type in sd_bus_message_append_basic3. In case of sd_bus_message_append_string_iovec(), the payload of iov is the string. It must satisfy the same constraints as described for the s type in sd_bus_message_append_basic3. The iov argument must point to n struct iovec structures. Each structure may have the iov_base field set, in which case the memory pointed to will be copied into the message, or unset, in which case a block of spaces (ASCII 32) of length iov_len will be inserted. The memory pointed at by iov may be changed after this call. The sd_bus_message_append_string_space() function appends space for a string to message m. It behaves similar to sd_bus_message_append_basic() with type s, but instead of copying a string into the message, it returns a pointer to the destination area to the caller in pointer p. Space for the string of length size plus the terminating NUL is allocated. On success, those calls return 0 or a positive integer. On failure, they return a negative errno-style error code. systemd1, sd-bus3, sd_bus_message_append_basic3, The D-Bus specification