Now parsing commandline arguments.

CMakeLists.txt

@@ -5,7 +5,7 @@ if(CMAKE_BUILD_TYPE STREQUAL "")
     set(CMAKE_BUILD_TYPE RelWithDebInfo)
 endif()
 
-set(CMAKE_C_FLAGS "-std=gnu99 -Wall -Wextra -Werror -Wpedantic -Wmissing-declarations -Wfatal-errors -pedantic-errors")
+set(CMAKE_C_FLAGS "-std=c11 -Wall -Wextra -Werror -Wpedantic -Wfatal-errors -Wmissing-declarations -pedantic-errors")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS} -g -O0")
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS} -O3")
 set(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS} -g -O3")

src/Main.c

@@ -1,14 +1,74 @@
 #include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <getopt.h>
+#include <unistd.h>
 
-// 0 = false;
-// 1 = true;
-char version[16] = "v0.5";
-int verbose = 0;
+const char *version = "v0.5";
+bool helpFlag = false;
+bool versionFlag = false;
+bool verboseFlag = false;
+char *infile = NULL;
+
+inline void printHelp();
+
+int main(int argc, char **argv) {
+    int arg;
+
+    while((arg = getopt(argc, argv, "hvVf:")) != -1) {
+        switch(arg) {
+            case 'h':
+                helpFlag = true;
+                break;
+
+            case 'v':
+                verboseFlag = true;
+                break;
+
+            case 'V':
+                versionFlag = true;
+                break;
+
+            case 'f':
+                infile = optarg;
+                break;
+
+            case '?':
+                if(optopt == 'f') {
+                    fprintf(stderr, "Option -%c requires an argument.\n", optopt);
+                } else if(isprint(optopt)) {
+                    fprintf(stderr, "Unknown option `-%c'.\n", optopt);
+                } else {
+                    fprintf(stderr, "Unknown character `\\x%x'.\n", optopt);
+                }
+                return 1;
+
+            default:
+                abort();
+        }
+    }
+
+    if(helpFlag) {
+        printHelp();
+        return 0;
+    } else if(versionFlag) {
+        printf("%s\n", version);
+        return 0;
+    }
 
-int main(/*int argc, char **argv*/) {
     printf("MMMCalc %s, Copyright (c) 2016 Nicolás A. Ortega.\n", version);
     printf("This program comes with ABSOLUTELY NO WARRANTY.\n");
     printf("This program is free software and you are welcome to redistribute\n");
     printf("under the terms and conditions of the GNU GPLv3 or higher.\n\n");
     return 0;
 }
+
+void printHelp() {
+    printf("Usage: mmmcalc [options]\n");
+    printf("Options:\n");
+    printf(" -f <file> -- The file to read variables from.\n");
+    printf(" -h -- Show this help information.\n");
+    printf(" -v -- Be verbose, prints the equations used.\n");
+    printf(" -V -- Print the version number.\n");
+}