CHK
#define CHK(s) (*arg == s[0] && !strcmp(arg, s))
#define CHK(s) (*p == s[0] && !strcmp(p, s))
#define CHK(s) (!strcmp(name, s))
#define CHK(fld) do { \
#define CHK(val, dft) (val <= 0 ? dft : val)
#define CHK(s) (*name == s[0] && !strcmp(name, s))