The C in v7 is, canonically, the language described in K&R, right?

I must be doing something dumb.

I am getting Webb Miller’s “s” editor built there, and I am down to one function.

/* chop_arg - chop a function's argument to a maximum length */
static chop_arg(fcn, arg, maxlen)
int (*fcn)();
int maxlen;
char *arg;
    char save;

    save = arg[maxlen];
    arg[maxlen] = '\0';
    arg[maxlen] = save;

This doesn’t like the function pointer.

$ cc -c choparg.c
choparg.c:11: Call of non-function

So, uh, what is the obvious thing I am missing?  How am I supposed to be passing function pointers in the C compiler that comes with v7?