Why use bzero over memset?
In a Systems Programming class I took this previous semester, we had to implement a basic client/server in C. When initializing the structs, like sock_addr_in, or char buffers (that we used to send data back and forth between client and server) the professor instructed us to only use bzero and not memset to initialize them. He never explained why, and I'm curious if there is a valid reason for this?
I see here: http://fdiv.net/2009/01/14/memset-vs-bzero-ultimate-showdown that bzero is more efficient due to the fact that is only ever going to be zeroing memory, so it doesn't have to do any additional checking that memset may do. That still doesn't necessarily seem like a reason to absolutely not use memset for zeroing memory though.
bzero is considered deprecated, and furthermore is a not a standard C function. According to the manual, memset is preferred over bzero for this reason. So why would you want to still use bzero over memset? Just for the efficiency gains, or is it something more? Likewise, what are the benefits of memset over bzero that make it the de facto preferred option for newer programs?
Answer
I don't see any reason to prefer bzero over memset.
memset is a standard C function while bzero has never been a C standard function. The rationale is probably because you can achieve exactly the same functionality using memset function.
Now regarding efficiency, compilers like gcc use builtin implementations for memset which switch to a particular implementation when a constant 0 is detected. Same for glibc when builtins are disabled.