1 /* vi: set sw=4 ts=4: */
3 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9 /* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
17 enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) };
18 #define G (*(struct globals*)&bb_common_bufsiz1)
19 #define pointer (G.pointer )
20 #define base (G.base )
21 #define stack (G.stack )
22 #define INIT_G() do { \
27 static void push(double a)
29 if (pointer >= STACK_SIZE)
30 bb_error_msg_and_die("stack overflow");
34 static double pop(void)
37 bb_error_msg_and_die("stack underflow");
38 return stack[--pointer];
48 double subtrahend = pop();
50 push(pop() - subtrahend);
58 #if ENABLE_FEATURE_DC_LIBM
59 static void power(void)
61 double topower = pop();
63 push(pow(pop(), topower));
67 static void divide(void)
69 double divisor = pop();
71 push(pop() / divisor);
78 push((unsigned) pop() % d);
83 push((unsigned) pop() & (unsigned) pop());
88 push((unsigned) pop() | (unsigned) pop());
93 push((unsigned) pop() ^ (unsigned) pop());
98 push(~(unsigned) pop());
101 static void set_output_base(void)
103 static const char bases[] ALIGN1 = { 2, 8, 10, 16, 0 };
104 unsigned b = (unsigned)pop();
106 base = *strchrnul(bases, b);
108 bb_error_msg("error, base %u is not supported", b);
113 static void print_base(double print)
118 printf("%g\n", print);
130 default: /* base 2 */
131 i = (unsigned)INT_MAX + 1;
137 bb_putchar('1' - !(x & i));
144 static void print_stack_no_pop(void)
146 unsigned i = pointer;
148 print_base(stack[--i]);
151 static void print_no_pop(void)
153 print_base(stack[pointer-1]);
158 void (*function) (void);
161 static const struct op operators[] = {
170 #if ENABLE_FEATURE_DC_LIBM
183 {"f", print_stack_no_pop},
184 {"o", set_output_base},
185 { /* zero filled */ }
188 static void stack_machine(const char *argument)
192 const struct op *o = operators;
197 d = strtod(argument, &endPointer);
199 if (endPointer != argument) {
205 if (strcmp(o->name, argument) == 0) {
211 bb_error_msg_and_die("%s: syntax error", argument);
214 /* return pointer to next token in buffer and set *buffer to one char
215 * past the end of the above mentioned token
217 static char *get_token(char **buffer)
219 char *current = skip_whitespace(*buffer);
220 if (*current != '\0') {
221 *buffer = skip_non_whitespace(current);
227 int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
228 int dc_main(int argc UNUSED_PARAM, char **argv)
234 /* take stuff from stdin if no args are given */
238 while ((line = xmalloc_fgetline(stdin)) != NULL) {
241 token = get_token(&cursor);
244 stack_machine(token);
249 if (argv[0][0] == '-')
252 stack_machine(*argv);