# sd_bus_message_read_strv 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 \ 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 # Description `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. # Return Value On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code. ## Errors 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. # History `sd_bus_message_read_strv()` was added in version 246. `sd_bus_message_read_strv_extend()` was added in version 252. # See Also `systemd(1)`, `sd-bus(3)`, `sd_bus_message_read(3)`