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-rw-r--r--miscutils/dc.c94
1 files changed, 43 insertions, 51 deletions
diff --git a/miscutils/dc.c b/miscutils/dc.c
index ffc3f8d..68ecd8a 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -8,11 +8,18 @@
/* Tiny RPN calculator, because "expr" didn't give me bitwise operations. */
-enum { STACK_SIZE = COMMON_BUFSIZE / sizeof(double) };
-#define stack ((double*)&bb_common_bufsiz1)
-static unsigned int pointer;
-static unsigned char base;
+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 )
+
static void push(double a)
{
@@ -61,34 +68,34 @@ static void divide(void)
static void mod(void)
{
- unsigned int d = pop();
+ unsigned d = pop();
- push((unsigned int) pop() % d);
+ push((unsigned) pop() % d);
}
static void and(void)
{
- push((unsigned int) pop() & (unsigned int) pop());
+ push((unsigned) pop() & (unsigned) pop());
}
static void or(void)
{
- push((unsigned int) pop() | (unsigned int) pop());
+ push((unsigned) pop() | (unsigned) pop());
}
static void eor(void)
{
- push((unsigned int) pop() ^ (unsigned int) pop());
+ push((unsigned) pop() ^ (unsigned) pop());
}
static void not(void)
{
- push(~(unsigned int) pop());
+ push(~(unsigned) pop());
}
static void set_output_base(void)
{
- base = (unsigned char)pop();
+ base = (unsigned)pop();
if ((base != 10) && (base != 16)) {
bb_error_msg("error, base %d is not supported", base);
base = 10;
@@ -98,14 +105,14 @@ static void set_output_base(void)
static void print_base(double print)
{
if (base == 16)
- printf("%x\n", (unsigned int)print);
+ printf("%x\n", (unsigned)print);
else
printf("%g\n", print);
}
static void print_stack_no_pop(void)
{
- unsigned int i = pointer;
+ unsigned i = pointer;
while (i)
print_base(stack[--i]);
}
@@ -142,12 +149,12 @@ static const struct op operators[] = {
{"p", print_no_pop},
{"f", print_stack_no_pop},
{"o", set_output_base},
- {"", 0}
+ { /* zero filled */ }
};
static void stack_machine(const char *argument)
{
- char *endPointer = 0;
+ char *endPointer;
double d;
const struct op *o = operators;
@@ -176,54 +183,39 @@ static void stack_machine(const char *argument)
*/
static char *get_token(char **buffer)
{
- char *start = NULL;
- char *current;
-
- current = skip_whitespace(*buffer);
- if (*current != 0) {
- start = current;
- current = skip_non_whitespace(current);
- *buffer = current;
+ char *current = skip_whitespace(*buffer);
+ if (*current != '\0') {
+ *buffer = skip_non_whitespace(current);
+ return 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;
+ return NULL;
}
int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-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))) {
+int dc_main(int argc ATTRIBUTE_UNUSED, char **argv)
+{
+ argv++;
+ if (!argv[0]) {
+ /* take stuff from stdin if no args are given */
+ char *line;
+ char *cursor;
+ char *token;
+ while ((line = xmalloc_getline(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] == '-')
+ if (argv[0][0] == '-')
bb_show_usage();
- while (argc >= 2) {
- stack_machine(argv[1]);
- argv++;
- argc--;
- }
+ do {
+ stack_machine(*argv);
+ } while (*++argv);
}
return EXIT_SUCCESS;
}