dc: fix "small dc" to have standard command line API

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 48 insertions, 25 deletions

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 24e4b6392..e543b2b93 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -159,8 +159,7 @@
 //usage:
 //usage:#define dc_full_usage "\n"
 //usage:     "\nTiny RPN calculator. Operations:"
-//usage:     "\n+, -, *, /, %, ^, exp, ~, divmod, |, "
-//usage:       "modular exponentiation,"
+//usage:     "\n+, -, *, /, %, ~, ^, |,"
 //usage:     "\np - print top of the stack (without popping)"
 //usage:     "\nf - print entire stack"
 //usage:     "\nk - pop the value and set the precision"
diff --git a/miscutils/dc.c b/miscutils/dc.c
index bca4778bf..17fdda8fd 100644
--- a/miscutils/dc.c
+++ b/miscutils/dc.c
@@ -20,7 +20,6 @@ typedef unsigned long long data_t;
 #define DATA_FMT "ll"
 #endif
 
-
 struct globals {
         unsigned pointer;
         unsigned base;
@@ -36,7 +35,6 @@ enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(
         base = 10; \
 } while (0)
 
-
 static void check_under(void)
 {
         if (pointer == 0)
@@ -184,25 +182,25 @@ struct op {
 
 static const struct op operators[] = {
 #if ENABLE_FEATURE_DC_LIBM
-        {"**",  power},
-        {"exp", power},
-        {"pow", power},
+        {"^",   power},
+//      {"exp", power},
+//      {"pow", power},
 #endif
         {"%",   mod},
-        {"mod", mod},
+//      {"mod", mod},
+        // logic ops are not standard, remove?
         {"and", and},
         {"or",  or},
         {"not", not},
-        {"eor", eor},
         {"xor", eor},
         {"+",   add},
-        {"add", add},
+//      {"add", add},
         {"-",   sub},
-        {"sub", sub},
+//      {"sub", sub},
         {"*",   mul},
-        {"mul", mul},
+//      {"mul", mul},
         {"/",   divide},
-        {"div", divide},
+//      {"div", divide},
         {"p", print_no_pop},
         {"f", print_stack_no_pop},
         {"o", set_output_base},
@@ -243,24 +241,50 @@ static void stack_machine(const char *argument)
         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();
 
-//TODO: fix this, should take: dc -eSCRIPT -fFILE FILE
-        argv++;
-        if (!argv[0]) {
-                /* take stuff from stdin if no args are given */
-                char *line;
-                while ((line = xmalloc_fgetline(stdin)) != NULL) {
-                        stack_machine(line);
-                        free(line);
+        /* 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();
                 }
-        } else {
-                do {
-                        stack_machine(*argv);
-                } while (*++argv);
         }
+        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;
 }