/* vi: set sw=4 ts=4: */ /* * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ /* config/applet/usage bits are in bc.c */ //#include "libbb.h" //#include "common_bufsiz.h" #include <math.h> #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 { \ setup_common_bufsiz(); \ base = 10; \ } while (0) static void check_under(void) { if (pointer == 0) bb_error_msg_and_die("stack underflow"); } static void push(double a) { if (pointer >= STACK_SIZE) bb_error_msg_and_die("stack overflow"); stack[pointer++] = a; } static double pop(void) { check_under(); return stack[--pointer]; } static void add(void) { push(pop() + pop()); } static void sub(void) { double subtrahend = pop(); push(pop() - subtrahend); } 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) { double divisor = pop(); push(pop() / divisor); } static void mod(void) { data_t d = pop(); push((data_t) pop() % d); } static void and(void) { push((data_t) pop() & (data_t) pop()); } static void or(void) { push((data_t) pop() | (data_t) pop()); } static void eor(void) { push((data_t) pop() ^ (data_t) pop()); } static void not(void) { push(~(data_t) pop()); } static void set_output_base(void) { 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) { 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 i = pointer; while (i) print_base(stack[--i]); } static void print_no_pop(void) { check_under(); print_base(stack[pointer-1]); } struct op { const char name[4]; void (*function) (void); }; static const struct op operators[] = { #if ENABLE_FEATURE_DC_LIBM {"^", power}, // {"exp", power}, // {"pow", power}, #endif {"%", mod}, // {"mod", mod}, // logic ops are not standard, remove? {"and", and}, {"or", or}, {"not", not}, {"xor", eor}, {"+", add}, // {"add", add}, {"-", sub}, // {"sub", sub}, {"*", mul}, // {"mul", mul}, {"/", divide}, // {"div", divide}, {"p", print_no_pop}, {"f", print_stack_no_pop}, {"o", set_output_base}, }; /* Feed the stack machine */ static void stack_machine(const char *argument) { char *end; double number; const struct op *o; next: number = strtod(argument, &end); if (end != argument) { argument = end; push(number); goto next; } /* We might have matched a digit, eventually advance the argument */ argument = skip_whitespace(argument); if (*argument == '\0') return; o = operators; do { char *after_name = is_prefixed_with(argument, o->name); if (after_name) { argument = after_name; o->function(); goto next; } o++; } while (o != operators + ARRAY_SIZE(operators)); bb_error_msg_and_die("syntax error at '%s'", argument); } static void process_file(FILE *fp) { char *line; while ((line = xmalloc_fgetline(fp)) != NULL) { stack_machine(line); free(line); } } int dc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int dc_main(int argc UNUSED_PARAM, char **argv) { bool script = 0; INIT_G(); /* Run -e'SCRIPT' and -fFILE in order of appearance, then handle FILEs */ for (;;) { int n = getopt(argc, argv, "e:f:"); if (n <= 0) break; switch (n) { case 'e': script = 1; stack_machine(optarg); break; case 'f': script = 1; process_file(xfopen_for_read(optarg)); break; default: bb_show_usage(); } } argv += optind; if (*argv) { do process_file(xfopen_for_read(*argv++)); while (*argv); } else if (!script) { /* Take stuff from stdin if no args are given */ process_file(stdin); } return EXIT_SUCCESS; }