Add pointer test, and reading files.

Modify struct test, add flip bools test, and array test.

.vscode/settings.json

@@ -1,5 +1,8 @@
 {
     "files.associations": {
-        "math_functions.h": "c"
+        "math_functions.h": "c",
+        "pointer_test.h": "c",
+        "struct_test.h": "c",
+        "stdio.h": "c"
     }
 }

CMakeLists.txt

@@ -14,6 +14,8 @@ src/main.c
 src/hello.c
 src/math_functions.c
 src/struct_test.c
+src/pointer_test.c
+src/read_file.c
 )
 
 # https://discourse.cmake.org/t/how-to-properly-include-header-files/4762

src/main.c

@@ -6,6 +6,9 @@
 #include "math_functions.h"
 #include "hello.h"
 #include "struct_test.h"
+#include "pointer_test.h"
+#include "read_file.h"
+
 
 // Test
 // https://stackoverflow.com/questions/8666378/detect-windows-or-linux-in-c-c
@@ -13,6 +16,8 @@
 #include <Windows.h>
 #endif
 
+#include "stdbool.h"
+
 
 // TODO Move this into a different project.
 #ifdef _WIN32
@@ -23,14 +28,59 @@ void guiTest(){
 
 #endif
 
+// #define _FLIP_BOOLS
+// Hmm, very evil
+#ifdef _FLIP_BOOLS
+// This is just madness, inverting the boolean values :P
+#define true FALSE
+#define false TRUE
+// #define true (rand() % 2)
+// #define false (rand() % 2)
+#endif //_FLIP_BOOLS
+
 // TODO Look into making a gtk C program
 // https://www.geeksforgeeks.org/how-to-create-gui-in-c-programming-using-gtk-toolkit/
 
+// Print out the memory addresses for each item in an array.
+void array_test() {
+    // https://www.tutorialspoint.com/cprogramming/c_memory_address.htm
+    // Int array
+    int numbers[5] = {1,2,3,4,5};
+    int i = 0;
+
+    printf("numbers = %p\n", numbers);
+
+    do {
+        printf("numbers[%u] = %p\n", i, (void *)&numbers[i]);
+        i++;
+    } while (i < 5);
+
+    printf("sizeof(numbers) = %lu\n", sizeof(numbers));
+
+}
+
+// https://www.tutorialspoint.com/cprogramming/c_ternary_operator.htm
+void check_even_odd(int num) {
+    (num %2 == 0) ? printf("%d is even\n", num) : printf("%d is odd\n", num);
+}
+
+
 int main() {
     char welcomeMsg[] = "Welcome to KCNet";
     // printf(welcomeMsg);
 
     uint16_t test = -2;
+
+    // array_test();
+    // for (int i=0; i<5; i++) {
+    //     check_even_odd(i);
+    // }
+    // check_even_odd(1);
+
+    // new_struct();
+    read_file("test.txt");
+
+
     // This doesn't work
     // uint16_test();
 
@@ -42,7 +92,22 @@ int main() {
     // printf("Number: %" PRIu32, test);
 
     // mathFunctions();
-    print_struct();
+    // print_struct();
+    int i = 22222;
+    int* i_ptr = &i;
+    // pointer_madness(i_ptr);
+
+#ifdef _FLIP_BOOLS
+    bool testb = false;
+    if (testb) {
+        printf("True");
+    } else {
+        printf("False");
+    }
+
+#endif //_FLIP_BOOLS
+
+
     
     // printf_example();
     return 0;

src/pointer_test.c

@@ -0,0 +1,18 @@
+#include <stdio.h>
+#include "pointer_test.h"
+
+
+// https://www.freecodecamp.org/news/pointers-in-c-are-not-as-difficult-as-you-think/
+// https://www.tutorialspoint.com/cprogramming/c_pointers.htm
+
+// https://stackoverflow.com/questions/32914298/print-value-and-address-of-pointer-defined-in-function
+void pointer_madness(int* test) {
+    // int *test = 0;
+    // test = 2;
+
+    printf("Value pointed to: %i\n", *test);
+
+    printf("Address pointed to by test: 0x%x\n", (unsigned int)test);
+    printf("Address of test itself: 0x%x\n", (unsigned int) &test);
+
+}

src/pointer_test.h

@@ -0,0 +1 @@
+void pointer_madness(int* test);

src/read_file.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+// https://solarianprogrammer.com/2019/04/03/c-programming-read-file-lines-fgets-getline-implement-portable-getline/
+
+// This works! The file has to be where the .exe is which makes sense.
+void read_file(const char* file_name) {
+    FILE *fp = fopen(file_name, "r");
+
+    // Check if file exists
+    if (fp == NULL) {
+        // perror("Unable to open file %s!", file_name);
+        perror("Unable to open file! ");
+        exit(1);
+    }
+
+    char chunk[128];
+
+    while (fgets(chunk, sizeof(chunk), fp) != NULL) {
+        fputs(chunk, stdout);
+        // fputs("\n", stdout); // Marker string used to show where the content of the chunk array has ended.
+    }
+
+    // Close the file
+    fclose(fp);
+}

src/read_file.h

@@ -0,0 +1 @@
+void read_file(const char* file_name);

src/struct_test.c

@@ -7,6 +7,16 @@
 
 // https://www.w3schools.com/c/c_structs.php
 
+void new_struct() {
+    struct structT1_ s1;
+
+    strcpy(structT1.username, "user");
+    structT1.tag_number = 22;
+    // s1.username = "user";
+    // s1.tag_number = 22;
+
+    printf("Username: %s\nTag number: %i", structT1.username, structT1.tag_number);
+}
 
 void print_struct(){
     struct TestStruct s1;

src/struct_test.h

@@ -8,6 +8,12 @@ struct TestStruct {
     int age;
 };
 
+struct structT1_ {
+    char username[20];
+    int tag_number;
+
+} structT1;
+
 // Not sure how to use this
 #ifdef _TEST
 // https://stackoverflow.com/questions/10162152/how-to-work-with-string-fields-in-a-c-struct
@@ -25,4 +31,4 @@ char *addr, char*bd, char sex);
 #endif //_TEST
 
 void print_struct();
-
+void new_struct();