buffer_getline_sa - read line from buffer
#include <libowfat/stralloc.h>
#include <libowfat/buffer.h>
int buffer_getline_sa(buffer* b,stralloc* sa);
buffer_getline_sa appends data from the b to sa until a '\n' is
found, NOT overwriting the previous content of sa. The new-line is also
appended to sa.
If reading from the buffer or allocating memory fails,
buffer_getline_sa returns -1 and sets errno appropriately. At that
point sa may be empty or it may already contain a partial token.
-1 on error (setting errno), 0 on EOF, 1 when successful.
buffer_getline_sa appends instead of overwriting so it can be used on
non-blocking sockets (these signal error and set errno to EAGAIN; in
this case you can simply call buffer_getline_sa again when select or
poll indicate more data is available).
buffer_get_token_sa(3), buffer(3)