switch to using getopt for command line options

src/error.hxx

@@ -39,4 +39,12 @@ namespace err {
     inline void undeclared(std::optional<std::string> err) {
         std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mundeclared varible '" << err.value() << "'\033[0m" << std::endl;
     }
+
+    inline void nofile() {
+        std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mno input files\033[0m" << std::endl;
+    }
+
+    inline void help() {
+        std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mhelp no implemented... just... uhm... look at main.cxx?\033[0m" << std::endl;
+    }
 }

src/main.cxx

@@ -3,6 +3,7 @@
 #include <sstream>
 #include <optional>
 #include <vector>
+#include <getopt.h>
 
 #include "arena.hxx"
 #include "parser.hxx"
@@ -10,15 +11,52 @@
 #include "tokenization.hxx"
 
 int main(int argc, char* argv[]) {
-    if (argc != 2) {
+    std::string outfile = "out.asm";
-        std::cerr << "xlang: \033[1;31merror:\033[0m \033[1;37mno input files\033[0m" << std::endl; // yes i spent 10 minutes to emulate clangs output...
+    std::optional<std::string> infile;
+    int opt;
+    struct option long_options[] = {
+        {"help", no_argument, nullptr, 'h'},
+        {"version", no_argument, nullptr, 'v'},
+        {"output", required_argument, nullptr, 'o'},
+        {nullptr, 0, nullptr, 0}
+    };
+
+    while (true) {
+        int option_index = 0;
+        opt = getopt_long(argc, argv, "hvo:", long_options, &option_index);
+        if (opt == -1) break;
+
+        switch (opt) {
+            case 'h':
+                err::help();
+                break;
+            case 'v':
+                std::cout << "Version 0.0.1a\n";
+                break;
+            case 'o':
+                outfile = optarg;
+                break;
+            default:
+                err::help();
+                return EXIT_FAILURE;
+        }
+    }
+
+    if (optind < argc) {
+        infile = argv[optind];
+    } else {
+        err::nofile();
         return EXIT_FAILURE;
     }
 
+    if (!infile.has_value()) {
+        err::nofile();
+        return EXIT_FAILURE;
+    }
     std::string contents;
     {
         std::stringstream contents_stream;
-        std::fstream input(argv[1], std::ios::in);
+        std::fstream input(infile.value(), std::ios::in);
         contents_stream << input.rdbuf();
         contents = contents_stream.str();
     }
@@ -37,11 +75,13 @@ int main(int argc, char* argv[]) {
     Generator generator(prog.value());
 
     {
-        std::fstream output("out.asm", std::ios::out);
+        std::fstream output(outfile, std::ios::out);
         output << generator.gen_prog();
     }
 
-    system("nasm -felf64 out.asm");
+    std::stringstream nasmcmd;
+    nasmcmd << "nasm -felf64 " << outfile;
+    system(nasmcmd.str().c_str());
     system("ld -o out out.o");
 
     return EXIT_SUCCESS;