Final

HW9b.c

@@ -10,39 +10,53 @@
 #include <stdlib.h>
 #include <string.h>
 
+// Globals
+// ptr_size is number of chars in stack
+// ptr is pointer to stack memory
 int ptr_size = 0;
 char* ptr;
 
+// Pushes parameter addition to stack
 void push(char addition) {
-    // Deal with allocation every time push is called and pop. If not initialized, the source is NULL
+    // Deal with allocation every time push is called and pop. If not initialized, the source is NULL to initialize
+    // Add one to the current size, and realloc using the extended memory
     ptr = realloc((ptr_size == 0)? NULL: ptr, (ptr_size+1)*sizeof(char));
+    // Set the item at the new maximum position and increment the size after it is stored
     *(ptr+ptr_size) = addition;
     ptr_size++;
 }
 
+// Takes the last element off the stack and returns it
 char pop() {
+    // Before data is adjusted, take the item to be removed out and store for returning later
     char removal = *(ptr+ptr_size-1);
     ptr_size--;
+    // Deal with allocation every time push is called and pop. If not initialized, the source is NULL to initialize
+    // Realloc the memory, effectively "deleting" the newest, now "popped"
     ptr = realloc((ptr_size == 0)? NULL:ptr, (ptr_size)*sizeof(char));
     return removal;
 }
 
+// Prints the entire stack
 void print() {
+    // Starts at the end, where the start of the stack is
     for (int i = ptr_size - 1; i >= 0; i--)
         printf("%c\n",*(ptr+i));
 }
 
 int main() {
     char input[20] = "";
+    // Start input menu
     while(strncmp("quit",input,4)!= 0) {
-        printf("Enter command (push, print, or quit): ");
+        printf("Enter command (push, pop, print, or quit): ");
         fgets(input,20,stdin);
         // Strip newline character from input (fgets)
         for (int i=0;i<strlen(input);i++) if (input[i] == '\n') input[i] = '\0';
 
 
-        // Check if the first 4 letter of string are push, then process string for remaining integer
+        // Check if the first 4 letter of string are push
         if (strncmp("push",input,4) == 0) {
+            // Test for maximum
             if (ptr_size != 10) {
                 // Extract char from push. Should be slot 5
                 char temp = input[5];
@@ -51,7 +65,7 @@ int main() {
                 printf("Error: Maximum elements in the stack\n");
             }
         }
-
+        // Check if the first 3 letters of the string are pop
         if (strncmp("pop",input,3) == 0)
             printf("Popped: %c \n",pop());
 

HW9c.c

@@ -11,14 +11,20 @@
 #include "PEASE.h"
 
 int main() {
+    // Input string
     printf("Reverse a phrase: ");
     char input[20];
     fgets(input,20,stdin);
+    // Strip newline
     for (int i=0;i<strlen(input);i++) if (input[i] == '\n') input[i] = '\0';
+
+    // Start String Reversal, reversal string only has to be as long as the input string
     char reverse[strlen(input)];
+    // Two Loops, one to throw in the stack....
     for (int i = 0; i < strlen(input); i++) {
         push(input[i]);
     }
+    // ... one to yank it back out again
     for (int i = 0; i < strlen(input); i++) {
         reverse[i] = pop();
     }

PEASE.h

@@ -1,24 +1,19 @@
 // Library File for Part C adapting my code from part B
-
 #ifndef PEASE_H_
 #define PEASE_H_
 #include <stdlib.h>
 
 int ptr_size = 0;
 char* ptr;
-
 void push(char addition) {
-    // Deal with allocation every time push is called and pop. If not initialized, the source is NULL
     ptr = realloc((ptr_size == 0)? NULL: ptr, (ptr_size+1)*sizeof(char));
     *(ptr+ptr_size) = addition;
     ptr_size++;
 }
-
 char pop() {
     char removal = *(ptr+ptr_size-1);
     ptr_size--;
     ptr = realloc((ptr_size == 0)? NULL: ptr, (ptr_size)*sizeof(char));
     return removal;
 }
-
 #endif

command_line_input.c

@@ -1,50 +0,0 @@
-#include <stdio.h>
-
-/*
- * Users can pass command line arguments when they execute a C program
- *
- * e.g., following command will execute the 'test_program' and supply 5 as the first argument
- * ./test_program 5
- *
- * e.g., following command will execute the 'test_program' and supply "COS135" as the first argument and "Hello" as the second
- * ./test_program COS135 Hello
- *
- * Notice the change to the main() function, int argc, char *argv[]
- * int argc - refers to the number of arguments passed (including the program name; so if you are passing one argument, the value of argc will be 2)
- * char *argv[] - is a pointer array which points to each argument passed to the program
- *
- * Noted that argv[0] holds the name of the program itself and argv[1] is a pointer to the first command line argument supplied,
- * and *argv[n] is the last argument.
- * If no arguments are supplied, argc will be one, and if you pass one argument then argc is set at 2.
- *
- */
-
-int main(int argc, char *argv[])  // note the change to the parameters in the main() function
-{
-    
-    // argv[0] is always the program name
-    printf("Program name %s\n", argv[0]);
-    
-    // argc contains the number of arguments supplied.
-    // if no arguments, it is 1 as the first argument, by default, is the program name
-    printf("There are %d arguments.\n", argc);
-    
-    // The first argument is at argv[1] array location. Note that these values are in char arrays (i.e., strings)
-    // you can use functions in stdlib.h to convert to numbers, if necessary
-    // e.g., atoi(), atof(), strtod(), or strtol() functions
-    // check sample codes at week8-2-codes.zip
-    // note: you cannot typecast string (char array) to int
-    if( argc == 2 ) {
-        printf("The first argument supplied is %s\n", argv[1]);
-    }
-    else if( argc > 2 ) {
-        printf("More than one arguments supplied. The list of arguments supplied are: \n");
-        // using a loop to output all the arguments
-        for(int i = 1; i < argc; i++)
-            printf("%s\n", argv[i]);
-        putchar('\n');
-    }
-    else {  // just making sure at least one argument should be given
-        printf("One argument expected.\n");
-    }
-}