buffer_putalign - write binary data to buffer
,const char* x
buffer_putalign is similar to buffer_put.
The difference to buffer_put is that, when there isn't enough space for new
data, buffer_put calls buffer_flush before copying any data, while
buffer_putalign fills all available space with data before calling
0 if everything is fine, -1 on error (setting errno
buffer_put(3), buffer_putsalign(3), buffer_flush(3), buffer(3)