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-rw-r--r--dc.c182
1 files changed, 0 insertions, 182 deletions
diff --git a/dc.c b/dc.c
deleted file mode 100644
index 8d7a92a..0000000
--- a/dc.c
+++ /dev/null
@@ -1,182 +0,0 @@
-/* vi: set sw=4 ts=4: */
-#include <ctype.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.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 void push(double a)
-{
- if (pointer >= (sizeof(stack) / sizeof(*stack)))
- error_msg_and_die("stack overflow");
- stack[pointer++] = a;
-}
-
-static double pop()
-{
- if (pointer == 0)
- error_msg_and_die("stack underflow");
- return stack[--pointer];
-}
-
-static void add()
-{
- push(pop() + pop());
-}
-
-static void sub()
-{
- double subtrahend = pop();
-
- push(pop() - subtrahend);
-}
-
-static void mul()
-{
- push(pop() * pop());
-}
-
-static void divide()
-{
- double divisor = pop();
-
- push(pop() / divisor);
-}
-
-static void and()
-{
- push((unsigned int) pop() & (unsigned int) pop());
-}
-
-static void or()
-{
- push((unsigned int) pop() | (unsigned int) pop());
-}
-
-static void eor()
-{
- push((unsigned int) pop() ^ (unsigned int) pop());
-}
-
-static void not()
-{
- push(~(unsigned int) pop());
-}
-
-static void print()
-{
- printf("%g\n", pop());
-}
-
-struct op {
- const char *name;
- void (*function) ();
-};
-
-static const struct op operators[] = {
- {"+", add},
- {"add", add},
- {"-", sub},
- {"sub", sub},
- {"*", mul},
- {"mul", mul},
- {"/", divide},
- {"div", divide},
- {"and", and},
- {"or", or},
- {"not", not},
- {"eor", eor},
- {0, 0}
-};
-
-static void stack_machine(const char *argument)
-{
- char *endPointer = 0;
- double d;
- const struct op *o = operators;
-
- if (argument == 0) {
- print();
- return;
- }
-
- d = strtod(argument, &endPointer);
-
- if (endPointer != argument) {
- push(d);
- return;
- }
-
- while (o->name != 0) {
- if (strcmp(o->name, argument) == 0) {
- (*(o->function)) ();
- return;
- }
- o++;
- }
- 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
- */
-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;
- }
- return start;
-}
-
-/* In Perl one might say, scalar m|\s*(\S+)\s*|g */
-static int number_of_tokens(char *buffer)
-{
- 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))) {
- cursor = line;
- len = number_of_tokens(line);
- for (i = 0; i < len; i++) {
- token = get_token(&cursor);
- *cursor++ = 0;
- stack_machine(token);
- }
- free(line);
- }
- } else {
- if (*argv[1]=='-')
- show_usage();
- while (argc >= 2) {
- stack_machine(argv[1]);
- argv++;
- argc--;
- }
- }
- stack_machine(0);
- return EXIT_SUCCESS;
-}