X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=miscutils%2Fdc.c;h=6903761e4f4b9983a7c31c5331fd5ce73aafae88;hb=604499e5a93d8055a761e968b12d6a0907bc3d0a;hp=61293755637e8def4ca739b6999074dab2db738d;hpb=d0a071a5281f8ba4b291f0c3beb74bee1f8df6a3;p=oweals%2Fbusybox.git diff --git a/miscutils/dc.c b/miscutils/dc.c index 612937556..6903761e4 100644 --- a/miscutils/dc.c +++ b/miscutils/dc.c @@ -1,25 +1,58 @@ /* 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, eor,\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 * 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) @@ -54,12 +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) { @@ -70,46 +105,77 @@ 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) @@ -138,9 +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}, @@ -151,7 +219,7 @@ static const struct op operators[] = { {"p", print_no_pop}, {"f", print_stack_no_pop}, {"o", set_output_base}, - { /* zero filled */ } + { "", NULL } }; static void stack_machine(const char *argument) @@ -160,41 +228,25 @@ static void stack_machine(const char *argument) double d; const struct op *o = operators; - if (argument == 0) - return; - d = strtod(argument, &endPointer); - if (endPointer != argument) { + if (endPointer != argument && *endPointer == '\0') { push(d); return; } - while (o->name[0]) { + while (o->function) { if (strcmp(o->name, argument) == 0) { o->function(); return; } o++; } - bb_error_msg_and_die("%s: syntax error", argument); -} - -/* 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(); @@ -204,19 +256,23 @@ int dc_main(int argc ATTRIBUTE_UNUSED, char **argv) 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);