diff options
Diffstat (limited to 'miscutils/dc.c')
-rw-r--r-- | miscutils/dc.c | 94 |
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; } |