a3: Kommentare hinzugefügt

src/c/a3.c

@@ -8,21 +8,22 @@ void memdump(unsigned char *string) {
 
     int columns = 16;
     int rows = 4;
-    char array[columns * rows];
+    char symbols[columns * rows];
 
     for(int i = 0; i < rows; i++) {
-        printf("%p\t", (void *) &string[i * columns]);
+        printf("%p\t", (void *) &string[i * columns]);//print address
 
         for (int j = i * columns; j < (i + 1) * columns; j++) {
-            printf("%02x ", string[j]);
-            if(string[j] < 0x20 || string[j] > 0x7e) array[j] = '.';
-            else array[j] = string[j];
+            printf("%02x ", string[j]);//print char number
+            if(string[j] < 0x20 || string[j] > 0x7e)//check for printable characters
+                symbols[j] = '.';
+            else symbols[j] = string[j];
         }
         printf(" ");
 
+        //print characters
         for (int j = i * columns; j < (i + 1) * columns; j++) {
-            printf("%c", array[j]);
-
+            printf("%c", symbols[j]);
         }
         printf("\n");
     }
@@ -32,10 +33,11 @@ void memdump(unsigned char *string) {
 int memreplace(char *string, char cin, char cout, char **caddr) {
     int found = 0;
     for (int i = 0; i < strlen(string); ++i) {
+        //if char is to be replaced
         if(string[i] == cin) {
+            string[i] = cout;//replace char
             found++;
-            string[i] = cout;
-            *caddr = &string[i];
+            *caddr = &string[i];//setting last found address
         }
     }
     return found;
@@ -49,11 +51,10 @@ int main(int argc, char **argv) {
 
     memdump((unsigned char *) argv[1]);
 
-
     printf("\tLaenge der Zeichenkette (inkl \\0): %i Byte(s)\n", (int) strlen(argv[1]));
     printf("\tErsetzen: '%c' mit '%c'\n", *argv[2], *argv[3]);
 
-    unsigned char *copy = malloc(4 * 16 * sizeof(char));
+    unsigned char *copy = malloc(4 * 16 * sizeof(char));//allocate memory for all chars
     strcpy((char *) copy, argv[1]);
 
     char *lastAddress = NULL;