/* vi: set sw=4 ts=4: */
/*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#include <math.h>
-/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
+//usage:#define dc_trivial_usage
+//usage: "EXPRESSION..."
+//usage:
+//usage:#define dc_full_usage "\n\n"
+//usage: "Tiny RPN calculator. Operations:\n"
+//usage: "+, add, -, sub, *, mul, /, div, %, mod, "IF_FEATURE_DC_LIBM("**, exp, ")"and, or, not, xor,\n"
+//usage: "p - print top of the stack (without popping),\n"
+//usage: "f - print entire stack,\n"
+//usage: "o - pop the value and set output radix (must be 10, 16, 8 or 2).\n"
+//usage: "Examples: 'dc 2 2 add p' -> 4, 'dc 8 8 mul 2 2 + / p' -> 16"
+//usage:
+//usage:#define dc_example_usage
+//usage: "$ dc 2 2 + p\n"
+//usage: "4\n"
+//usage: "$ dc 8 8 \\* 2 2 + / p\n"
+//usage: "16\n"
+//usage: "$ dc 0 1 and p\n"
+//usage: "0\n"
+//usage: "$ dc 0 1 or p\n"
+//usage: "1\n"
+//usage: "$ echo 72 9 div 8 mul p | dc\n"
+//usage: "64\n"
+
+#if 0
+typedef unsigned data_t;
+#define DATA_FMT ""
+#elif 0
+typedef unsigned long data_t;
+#define DATA_FMT "l"
+#else
+typedef unsigned long long data_t;
+#define DATA_FMT "ll"
+#endif
struct globals {
unsigned pointer;
unsigned base;
double stack[1];
-};
+} FIX_ALIASING;
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 { \
+ base = 10; \
} while (0)
push(pop() * pop());
}
+#if ENABLE_FEATURE_DC_LIBM
static void power(void)
{
double topower = pop();
push(pow(pop(), topower));
}
+#endif
static void divide(void)
{
static void mod(void)
{
- unsigned d = pop();
+ data_t d = pop();
- push((unsigned) pop() % d);
+ push((data_t) pop() % d);
}
static void and(void)
{
- push((unsigned) pop() & (unsigned) pop());
+ push((data_t) pop() & (data_t) pop());
}
static void or(void)
{
- push((unsigned) pop() | (unsigned) pop());
+ push((data_t) pop() | (data_t) pop());
}
static void eor(void)
{
- push((unsigned) pop() ^ (unsigned) pop());
+ push((data_t) pop() ^ (data_t) pop());
}
static void not(void)
{
- push(~(unsigned) pop());
+ push(~(data_t) pop());
}
static void set_output_base(void)
{
- base = (unsigned)pop();
- if ((base != 10) && (base != 16)) {
- bb_error_msg("error, base %d is not supported", base);
+ static const char bases[] ALIGN1 = { 2, 8, 10, 16, 0 };
+ unsigned b = (unsigned)pop();
+
+ base = *strchrnul(bases, b);
+ if (base == 0) {
+ bb_error_msg("error, base %u is not supported", b);
base = 10;
}
}
static void print_base(double print)
{
- if (base == 16)
- printf("%x\n", (unsigned)print);
- else
- printf("%g\n", print);
+ data_t x, i;
+
+ x = (data_t) print;
+ if (base == 10) {
+ if (x == print) /* exactly representable as unsigned integer */
+ printf("%"DATA_FMT"u\n", x);
+ else
+ printf("%g\n", print);
+ return;
+ }
+
+ switch (base) {
+ case 16:
+ printf("%"DATA_FMT"x\n", x);
+ break;
+ case 8:
+ printf("%"DATA_FMT"o\n", x);
+ break;
+ default: /* base 2 */
+ i = MAXINT(data_t) - (MAXINT(data_t) >> 1);
+ /* i is 100000...00000 */
+ do {
+ if (x & i)
+ break;
+ i >>= 1;
+ } while (i > 1);
+ do {
+ bb_putchar('1' - !(x & i));
+ i >>= 1;
+ } while (i);
+ bb_putchar('\n');
+ }
}
static void print_stack_no_pop(void)
{"mul", mul},
{"/", divide},
{"div", divide},
+#if ENABLE_FEATURE_DC_LIBM
{"**", power},
{"exp", power},
{"pow", power},
+#endif
{"%", mod},
{"mod", mod},
{"and", and},
{"p", print_no_pop},
{"f", print_stack_no_pop},
{"o", set_output_base},
- { /* zero filled */ }
};
static void stack_machine(const char *argument)
{
- char *endPointer;
+ char *end;
double d;
- const struct op *o = operators;
+ const struct op *o;
- if (argument == 0)
- return;
-
- d = strtod(argument, &endPointer);
-
- if (endPointer != argument) {
+ d = strtod(argument, &end);
+ if (end != argument && *end == '\0') {
push(d);
return;
}
- while (o->name[0]) {
+ o = operators;
+ do {
if (strcmp(o->name, argument) == 0) {
o->function();
return;
}
o++;
- }
- bb_error_msg_and_die("%s: syntax error", argument);
-}
+ } while (o != operators + ARRAY_SIZE(operators));
-/* 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 *current = skip_whitespace(*buffer);
- if (*current != '\0') {
- *buffer = skip_non_whitespace(current);
- return current;
- }
- return NULL;
+ bb_error_msg_and_die("syntax error at '%s'", argument);
}
int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int dc_main(int argc ATTRIBUTE_UNUSED, char **argv)
+int dc_main(int argc UNUSED_PARAM, char **argv)
{
INIT_G();
char *line;
char *cursor;
char *token;
- while ((line = xmalloc_getline(stdin)) != NULL) {
+ while ((line = xmalloc_fgetline(stdin)) != NULL) {
cursor = line;
while (1) {
- token = get_token(&cursor);
- if (!token) break;
- *cursor++ = '\0';
+ token = skip_whitespace(cursor);
+ if (*token == '\0')
+ break;
+ cursor = skip_non_whitespace(token);
+ if (*cursor != '\0')
+ *cursor++ = '\0';
stack_machine(token);
}
free(line);
}
} else {
- if (argv[0][0] == '-')
- bb_show_usage();
+ // why? it breaks "dc -2 2 + p"
+ //if (argv[0][0] == '-')
+ // bb_show_usage();
do {
stack_machine(*argv);
} while (*++argv);
projects / platform / upstream / busybox.git / blobdiff