/* vi: set sw=4 ts=4: */
-#include <ctype.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
#include <math.h>
-#include "busybox.h"
/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
-static double stack[100];
-static unsigned int pointer;
-static unsigned char base;
+
+struct globals {
+ unsigned pointer;
+ unsigned base;
+ double stack[1];
+};
+enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) };
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define pointer (G.pointer )
+#define base (G.base )
+#define stack (G.stack )
+#define INIT_G() do { } while (0)
+
static void push(double a)
{
- if (pointer >= (sizeof(stack) / sizeof(*stack)))
- error_msg_and_die("stack overflow");
+ if (pointer >= STACK_SIZE)
+ bb_error_msg_and_die("stack overflow");
stack[pointer++] = a;
}
static double pop(void)
{
if (pointer == 0)
- error_msg_and_die("stack underflow");
+ bb_error_msg_and_die("stack underflow");
return stack[--pointer];
}
push(pop() * pop());
}
+static void power(void)
+{
+ double topower = pop();
+
+ push(pow(pop(), topower));
+}
+
static void divide(void)
{
double divisor = pop();
push(pop() / divisor);
}
+static void mod(void)
+{
+ unsigned d = pop();
+
+ push((unsigned) pop() % d);
+}
+
static void and(void)
{
- push((unsigned int) pop() & (unsigned int) pop());
+ push((unsigned) pop() & (unsigned) pop());
}
static void or(void)
{
- push((unsigned int) pop() | (unsigned int) pop());
+ push((unsigned) pop() | (unsigned) pop());
}
static void eor(void)
{
- push((unsigned int) pop() ^ (unsigned int) pop());
+ push((unsigned) pop() ^ (unsigned) pop());
}
static void not(void)
{
- push(~(unsigned int) pop());
+ push(~(unsigned) pop());
}
static void set_output_base(void)
{
- base=(unsigned char)pop();
+ base = (unsigned)pop();
if ((base != 10) && (base != 16)) {
- fprintf(stderr, "Error: base = %d is not supported.\n", base);
- base=10;
+ bb_error_msg("error, base %d is not supported", base);
+ base = 10;
}
}
static void print_base(double print)
{
- if (base == 16)
- printf("%x\n", (unsigned int)print);
+ if (base == 16)
+ printf("%x\n", (unsigned)print);
else
- printf("%g\n", print);
+ printf("%g\n", print);
}
static void print_stack_no_pop(void)
{
- unsigned int i=pointer;
+ unsigned i = pointer;
while (i)
print_base(stack[--i]);
}
print_base(stack[pointer-1]);
}
-static void print(void)
-{
- print_base(pop());
-}
-
struct op {
- const char *name;
+ const char name[4];
void (*function) (void);
};
{"mul", mul},
{"/", divide},
{"div", divide},
+ {"**", power},
+ {"exp", power},
+ {"pow", power},
+ {"%", mod},
+ {"mod", mod},
{"and", and},
{"or", or},
{"not", not},
{"eor", eor},
+ {"xor", eor},
{"p", print_no_pop},
{"f", print_stack_no_pop},
{"o", set_output_base},
- {0, 0}
+ { /* zero filled */ }
};
static void stack_machine(const char *argument)
{
- char *endPointer = 0;
+ char *endPointer;
double d;
const struct op *o = operators;
- if (argument == 0) {
- print();
+ if (argument == 0)
return;
- }
d = strtod(argument, &endPointer);
return;
}
- while (o->name != 0) {
+ while (o->name[0]) {
if (strcmp(o->name, argument) == 0) {
- (*(o->function)) ();
+ o->function();
return;
}
o++;
}
- error_msg_and_die("%s: syntax error.", argument);
+ bb_error_msg_and_die("%s: syntax error", argument);
}
/* return pointer to next token in buffer and set *buffer to one char
- * past the end of the above mentioned token
+ * past the end of the above mentioned token
*/
static char *get_token(char **buffer)
{
- char *start = NULL;
- char *current = *buffer;
-
- while (isspace(*current)) { current++; }
- if (*current != 0) {
- start = current;
- while (!isspace(*current) && current != 0) { current++; }
- *buffer = current;
+ char *current = skip_whitespace(*buffer);
+ if (*current != '\0') {
+ *buffer = skip_non_whitespace(current);
+ return current;
}
- return start;
+ return NULL;
}
-/* In Perl one might say, scalar m|\s*(\S+)\s*|g */
-static int number_of_tokens(char *buffer)
+int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int dc_main(int argc UNUSED_PARAM, char **argv)
{
- int i = 0;
- char *b = buffer;
- while (get_token(&b)) { i++; }
- return i;
-}
+ INIT_G();
-int dc_main(int argc, char **argv)
-{
- /* take stuff from stdin if no args are given */
- if (argc <= 1) {
- int i, len;
- char *line = NULL;
- char *cursor = NULL;
- char *token = NULL;
- while ((line = get_line_from_file(stdin))) {
+ argv++;
+ if (!argv[0]) {
+ /* take stuff from stdin if no args are given */
+ char *line;
+ char *cursor;
+ char *token;
+ while ((line = xmalloc_fgetline(stdin)) != NULL) {
cursor = line;
- len = number_of_tokens(line);
- for (i = 0; i < len; i++) {
+ while (1) {
token = get_token(&cursor);
- *cursor++ = 0;
+ if (!token) break;
+ *cursor++ = '\0';
stack_machine(token);
}
free(line);
}
} else {
- if (*argv[1]=='-')
- show_usage();
- while (argc >= 2) {
- stack_machine(argv[1]);
- argv++;
- argc--;
- }
+ if (argv[0][0] == '-')
+ bb_show_usage();
+ do {
+ stack_machine(*argv);
+ } while (*++argv);
}
- stack_machine(0);
return EXIT_SUCCESS;
}