buffer_getline man page
buffer_getline — read line from buffer
ssize_t buffer_getline(buffer* b,char* x,size_t len);
buffer_getline copies data from b to x, x, ..., x[len-1] until len bytes have been copied or a new-line character ('\n') is encountered. That character is also copied.
Note that line is not 0-terminated to make reading lines with 0-bytes possible through this interface.
Number of bytes read (without '\n'), -1 on error (setting errno).
buffer_init(3), buffer_feed(3), buffer_peek(3), buffer_seek(3), buffer(3)