astol() - converts ASCII to long
astol(string,l)
char *string;
int *l;
astol() converts the characters pointed to by string to a long stored at l. It
returns a pointer to the first character in the string that was not used for
the conversion. If the entire string is to be used, it should point to a NULL
character ('\0'). Leading spaces and tabs are skipped.
extern char *astol();
if (*astod(string, &l) != '\0')
error("Not a number %s\n", string);
astod(3), astof(3), astoi(3)
Returns a pointer to first unused character.