>Ok, I understand, but how can I check the entire member?

Assuming the BOOL is being mapped to a 4-byte integer, you'd have to convert the string representation (which is in low-byte to high byte order), to an integer. In short if any of the bytes begininning at 21 and ending at 24 is not 0, the return value is true.

BTW, I believe Sergey may have erred in saying byte 19 was the beginning. The previous 5 members of the structure are 4 bytes each.