No file on common unix platforms is interpreted directly as machine code. Machine code executables have headers which contain information on the environment needed, memory mappings, program entry points etc. Binary executables are not just immediately jumped into, they must be opened by a loader which will parse these headers and do the required work before continuing execution in the program itself.

A zero-length binary fed into either ld.so (a.out loader) or ld-linux.so (elf loader) will not produce a zero-length output, but a parsing error.