X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=miscutils%2Fdc.c;h=6bcfbe2493a372ff3555e40c173af843567b3ee3;hb=577235dee826eed86d76b0d4ef866297a20ecd55;hp=ced5149df93103dd3af31cfd87b1f7ac21fc3764;hpb=74324c86663f57a19c1de303ee8c8e5449db9ef2;p=oweals%2Fbusybox.git diff --git a/miscutils/dc.c b/miscutils/dc.c index ced5149df..6bcfbe249 100644 --- a/miscutils/dc.c +++ b/miscutils/dc.c @@ -1,18 +1,60 @@ /* 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 -/* 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) -enum { STACK_SIZE = COMMON_BUFSIZE / sizeof(double) }; - -#define stack ((double*)&bb_common_bufsiz1) -static unsigned int pointer; -static unsigned char base; static void push(double a) { @@ -45,12 +87,14 @@ static void mul(void) push(pop() * pop()); } +#if ENABLE_FEATURE_DC_LIBM static void power(void) { double topower = pop(); push(pow(pop(), topower)); } +#endif static void divide(void) { @@ -61,51 +105,82 @@ static void divide(void) static void mod(void) { - unsigned int d = pop(); + data_t d = pop(); - push((unsigned int) pop() % d); + push((data_t) pop() % d); } static void and(void) { - push((unsigned int) pop() & (unsigned int) pop()); + push((data_t) pop() & (data_t) pop()); } static void or(void) { - push((unsigned int) pop() | (unsigned int) pop()); + push((data_t) pop() | (data_t) pop()); } static void eor(void) { - push((unsigned int) pop() ^ (unsigned int) pop()); + push((data_t) pop() ^ (data_t) pop()); } static void not(void) { - push(~(unsigned int) pop()); + push(~(data_t) pop()); } static void set_output_base(void) { - base = (unsigned char)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 int)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) { - unsigned int i = pointer; + unsigned i = pointer; while (i) print_base(stack[--i]); } @@ -129,9 +204,11 @@ static const struct op operators[] = { {"mul", mul}, {"/", divide}, {"div", divide}, +#if ENABLE_FEATURE_DC_LIBM {"**", power}, {"exp", power}, {"pow", power}, +#endif {"%", mod}, {"mod", mod}, {"and", and}, @@ -142,88 +219,63 @@ static const struct op operators[] = { {"p", print_no_pop}, {"f", print_stack_no_pop}, {"o", set_output_base}, - {"", 0} }; static void stack_machine(const char *argument) { - char *endPointer = 0; + char *end; double d; - const struct op *o = operators; - - if (argument == 0) - return; + const struct op *o; - 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 *start = NULL; - char *current; - - current = skip_whitespace(*buffer); - if (*current != 0) { - start = current; - current = skip_non_whitespace(current); - *buffer = current; - } - return start; + bb_error_msg_and_die("syntax error at '%s'", argument); } -/* In Perl one might say, scalar m|\s*(\S+)\s*|g */ -static int number_of_tokens(char *buffer) +int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int dc_main(int argc UNUSED_PARAM, char **argv) { - 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))) { + INIT_G(); + + argv++; + if (!argv[0]) { + /* take stuff from stdin if no args are given */ + char *line; + char *cursor; + char *token; + while ((line = xmalloc_fgetline(stdin)) != NULL) { cursor = line; - len = number_of_tokens(line); - for (i = 0; i < len; i++) { - token = get_token(&cursor); - *cursor++ = 0; + while (1) { + 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[1] == '-') - bb_show_usage(); - while (argc >= 2) { - stack_machine(argv[1]); - argv++; - argc--; - } + // why? it breaks "dc -2 2 + p" + //if (argv[0][0] == '-') + // bb_show_usage(); + do { + stack_machine(*argv); + } while (*++argv); } return EXIT_SUCCESS; }