Duplicate an argument vector. Simply scans through @var{vector},
duplicating each argument until the terminating @code{NULL} is found.
-Returns a pointer to the argument vector if successful. Returns
+Returns a pointer to the argument vector if successful. Returns
@code{NULL} if there is insufficient memory to complete building the
argument vector.
system with the single function call @code{freeargv}, which takes the
returned result of @code{buildargv}, as it's argument.
-Returns a pointer to the argument vector if successful. Returns
+Returns a pointer to the argument vector if successful. Returns
@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
memory to complete building the argument vector.