why is free() a void?

[Doug Gwyn]

In article <2604 at cirrusl.UUCP> dhesi%cirrusl at oliveb.ATC.olivetti.com (Rahul Dhesi) writes:
>Both free() and (*handler)() used to return int at one time.

They certainly did not.

Before the "void" type was added to the C language, the only way to declare
or define a function that didn't return a value was to just omit its return
type.  Unfortunately, as a programmer convenience the common type "int" was
also permitted to be elided in many declarations, including as the return
type for a function declaration/definition.  Thus, an actually-void function
had type indistinguishable from function-returning-int.  After "void" was
added, we cleaned up this overloading.  Old-style actually-void function
code for the most part will continue to work, signal handlers being the
notable exception.  (And even they generally continue to work in nearly all
implementations.)