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-rw-r--r--miscutils/dc.c65
1 files changed, 51 insertions, 14 deletions
diff --git a/miscutils/dc.c b/miscutils/dc.c
index cb4b1e9..ebf3572 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -6,7 +6,39 @@
#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, **, exp, and, or, not, eor,\n"
+//usage: "p - print top of the stack (without popping),\n"
+//usage: "f - print entire stack, o - pop the value and set output radix\n"
+//usage: "(value must be 10, 16, 8 or 2).\n"
+//usage: "Examples: 'dc 2 2 add' -> 4, 'dc 8 8 * 2 2 + /' -> 16\n"
+//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 {
@@ -73,29 +105,29 @@ 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)
@@ -112,25 +144,30 @@ static void set_output_base(void)
static void print_base(double print)
{
- unsigned x, i;
+ data_t x, i;
+ x = (data_t) print;
if (base == 10) {
- printf("%g\n", print);
+ if (x == print) /* exactly representable as unsigned integer */
+ printf("%"DATA_FMT"u\n", x);
+ else
+ printf("%g\n", print);
return;
}
- x = (unsigned)print;
switch (base) {
case 16:
- printf("%x\n", x);
+ printf("%"DATA_FMT"x\n", x);
break;
case 8:
- printf("%o\n", x);
+ printf("%"DATA_FMT"o\n", x);
break;
default: /* base 2 */
- i = (unsigned)INT_MAX + 1;
+ i = MAXINT(data_t) - (MAXINT(data_t) >> 1);
+ /* i is 100000...00000 */
do {
- if (x & i) break;
+ if (x & i)
+ break;
i >>= 1;
} while (i > 1);
do {