/* vi: set sw=4 ts=4: */
-#include "internal.h"
-#include <ctype.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
#include <math.h>
/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
-static double stack[100];
-static unsigned int pointer;
+
+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))) {
- errorMsg("stack overflow\n");
- exit(-1);
- } else
- stack[pointer++] = a;
+ if (pointer >= STACK_SIZE)
+ bb_error_msg_and_die("stack overflow");
+ stack[pointer++] = a;
}
-static double pop()
+static double pop(void)
{
- if (pointer == 0) {
- errorMsg("stack underflow\n");
- exit(-1);
- }
+ if (pointer == 0)
+ bb_error_msg_and_die("stack underflow");
return stack[--pointer];
}
-static void add()
+static void add(void)
{
push(pop() + pop());
}
-static void sub()
+static void sub(void)
{
double subtrahend = pop();
push(pop() - subtrahend);
}
-static void mul()
+static void mul(void)
{
push(pop() * pop());
}
-static void divide()
+static void power(void)
+{
+ double topower = pop();
+
+ push(pow(pop(), topower));
+}
+
+static void divide(void)
{
double divisor = pop();
push(pop() / divisor);
}
-static void and()
+static void mod(void)
+{
+ unsigned d = pop();
+
+ push((unsigned) pop() % d);
+}
+
+static void and(void)
+{
+ push((unsigned) pop() & (unsigned) pop());
+}
+
+static void or(void)
+{
+ push((unsigned) pop() | (unsigned) pop());
+}
+
+static void eor(void)
{
- push((unsigned int) pop() & (unsigned int) pop());
+ push((unsigned) pop() ^ (unsigned) pop());
}
-static void or()
+static void not(void)
{
- push((unsigned int) pop() | (unsigned int) pop());
+ push(~(unsigned) pop());
}
-static void eor()
+static void set_output_base(void)
{
- push((unsigned int) pop() ^ (unsigned int) pop());
+ base = (unsigned)pop();
+ if ((base != 10) && (base != 16)) {
+ bb_error_msg("error, base %d is not supported", base);
+ base = 10;
+ }
}
-static void not()
+static void print_base(double print)
{
- push(~(unsigned int) pop());
+ if (base == 16)
+ printf("%x\n", (unsigned)print);
+ else
+ printf("%g\n", print);
}
-static void print()
+static void print_stack_no_pop(void)
{
- printf("%g\n", pop());
+ unsigned i = pointer;
+ while (i)
+ print_base(stack[--i]);
+}
+
+static void print_no_pop(void)
+{
+ print_base(stack[pointer-1]);
}
struct op {
- const char *name;
- void (*function) ();
+ const char name[4];
+ void (*function) (void);
};
static const struct op operators[] = {
{"mul", mul},
{"/", divide},
{"div", divide},
+ {"**", power},
+ {"exp", power},
+ {"pow", power},
+ {"%", mod},
+ {"mod", mod},
{"and", and},
{"or", or},
{"not", not},
{"eor", eor},
- {0, 0}
+ {"xor", eor},
+ {"p", print_no_pop},
+ {"f", print_stack_no_pop},
+ {"o", set_output_base},
+ { /* 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++;
}
- errorMsg("%s: syntax error.\n", argument);
- exit(-1);
+ 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;
-}
-
-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))) {
+ INIT_G();
+
+ 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]=='-')
- usage(dc_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( TRUE);
+ return EXIT_SUCCESS;
}
projects / oweals / busybox.git / blobdiff