What's the use of memset() return value?

问题

memset() is declared to return void* that is always the same value as the address passed into the function.

What's the use of the return value? Why does it not return void?

回答1:

The signature is in line with all the other similar functions: memcpy(), strcpy() etc. I always thought this was done to enable one to chain calls to such functions, and to otherwise use such calls in expressions.

That said, I've never come across a real-world situation where I would feel compelled to use the return value in such a manner.

回答2:

It may be used for call chaining like:

char a[200];
strcpy(memset(a, 0, 200), "bla");

回答3:

In order to use the function as an argument for another function such as sprintf

回答4:

I came across this question when Googling to see what memset returned.

I have some code where I test for one value, then if that is true test to see if a value is zeros.

Because there is no completely portable way in C to test for zeros I have to run memset in the middle.

So my code is:

if ( a==true && (memcmp(memset(zeros, 0, sizeof(zeros)), b, sizeof(zeros)) == 0) )

This speaks to the chaining purpose listed in the previous questions, but it is an example of a use for this technique.

I'll leave it to others to judge if this is good coding or not.

来源：https://stackoverflow.com/questions/13720428/whats-the-use-of-memset-return-value