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Diffstat (limited to 'i/pc104/initrd/conf/busybox/miscutils/dc.c')
-rw-r--r--i/pc104/initrd/conf/busybox/miscutils/dc.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/i/pc104/initrd/conf/busybox/miscutils/dc.c b/i/pc104/initrd/conf/busybox/miscutils/dc.c
new file mode 100644
index 0000000..2121f76
--- /dev/null
+++ b/i/pc104/initrd/conf/busybox/miscutils/dc.c
@@ -0,0 +1,232 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "busybox.h"
+#include <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <math.h>
+
+/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
+
+static double stack[100];
+static unsigned int pointer;
+static unsigned char base;
+
+static void push(double a)
+{
+ if (pointer >= (sizeof(stack) / sizeof(*stack)))
+ bb_error_msg_and_die("stack overflow");
+ stack[pointer++] = a;
+}
+
+static double pop(void)
+{
+ if (pointer == 0)
+ bb_error_msg_and_die("stack underflow");
+ return stack[--pointer];
+}
+
+static void add(void)
+{
+ push(pop() + pop());
+}
+
+static void sub(void)
+{
+ double subtrahend = pop();
+
+ push(pop() - subtrahend);
+}
+
+static void mul(void)
+{
+ 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 int d = pop();
+
+ push((unsigned int) pop() % d);
+}
+
+static void and(void)
+{
+ push((unsigned int) pop() & (unsigned int) pop());
+}
+
+static void or(void)
+{
+ push((unsigned int) pop() | (unsigned int) pop());
+}
+
+static void eor(void)
+{
+ push((unsigned int) pop() ^ (unsigned int) pop());
+}
+
+static void not(void)
+{
+ push(~(unsigned int) pop());
+}
+
+static void set_output_base(void)
+{
+ base=(unsigned char)pop();
+ if ((base != 10) && (base != 16)) {
+ fprintf(stderr, "Error: base = %d is not supported.\n", base);
+ base=10;
+ }
+}
+
+static void print_base(double print)
+{
+ if (base == 16)
+ printf("%x\n", (unsigned int)print);
+ else
+ printf("%g\n", print);
+}
+
+static void print_stack_no_pop(void)
+{
+ unsigned int 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) (void);
+};
+
+static const struct op operators[] = {
+ {"+", add},
+ {"add", add},
+ {"-", sub},
+ {"sub", sub},
+ {"*", mul},
+ {"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}
+};
+
+static void stack_machine(const char *argument)
+{
+ char *endPointer = 0;
+ double d;
+ const struct op *o = operators;
+
+ if (argument == 0)
+ 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++;
+ }
+ 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
+ */
+static char *get_token(char **buffer)
+{
+ char *start = NULL;
+ char *current;
+
+ current = skip_whitespace(*buffer);
+ 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);
+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 = xmalloc_getline(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]=='-')
+ bb_show_usage();
+ while (argc >= 2) {
+ stack_machine(argv[1]);
+ argv++;
+ argc--;
+ }
+ }
+ return EXIT_SUCCESS;
+}