systemd sd_bus_message_read_strv 3 sd_bus_message_read_strv sd_bus_message_read_strv_extend Access an array of strings in a message #include <systemd/sd-bus.h> int sd_bus_message_read_strv sd_bus_message *m char ***l int sd_bus_message_read_strv_extend sd_bus_message *m char ***l sd_bus_message_read_strv() reads an array of string-like items from the message m. The "read pointer" in the message must be right before an array of strings (D-Bus type as), object paths (D-Bus type ao), or signatures (D-Bus type ag). On success, a pointer to a NULL-terminated array of strings (strv) is returned in the output parameter l. Note that ownership of this array is transferred to the caller. Hence, the caller is responsible for freeing this array and its contents. Also note that as a matter of optimization, if an empty array is encountered a NULL pointer might be returned here, and should be considered equivalent to an array with zero entries. sd_bus_message_read_strv_extend() is similar, but the second parameter is an input-output parameter. If *l is NULL, if behaves identically to sd_bus_message_read_strv(). Otherwise, *l must point to a strv, which will be reallocated and extended with additional strings. This function is particularly useful when combining multiple lists of strings in a message or messages into a single array of strings. On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code. Returned errors may indicate the following problems: -EINVAL m or l are NULL. -EPERM The message is not sealed. -EBADMSG The message cannot be parsed. -ENXIO The message "read pointer" is not right before an array of the appropriate type. sd_bus_message_read_strv() was added in version 246. sd_bus_message_read_strv_extend() was added in version 252. systemd1 sd-bus3 sd_bus_message_read3