The Unix command /bin/true (do nothing, exit with code zero) can be implemented as an empty file. When it's run, the kernel doesn't recognize it as binary code,

The Unix command /bin/true (do nothing, exit with code zero) can be implemented as an empty file. When it's run, the kernel doesn't recognize it as binary code, so it gives it to /bin/sh to run. There's at least two bugs in a zero-byte implementation of /bin/true: it's too slow and it uses too much memory.