change message size cap (was 128) to INT64_MAX

src/caesarcrypt.c

@@ -12,9 +12,8 @@
 #include "dyninput.h"
 
 #include <stdio.h>
+#include <stdint.h>
 #include <stdlib.h>
-#include <string.h>
-#include <stdbool.h>
 
 
 int main()
@@ -26,14 +25,17 @@ int main()
 		,stdout
 	);
 	char buf[4];
+	int64_t maxsize = INT64_MAX;
 	fgets(buf, 3, stdin);
 	int choice = strtol(buf, NULL, 10);
-	
-	//char* msg = calloc(128, sizeof(char));
 
 	fputs("Enter your message text: ", stdout);
-	//if (msg) fgets(msg, 128, stdin);
-	char* msg = dyninput_str(INT64_MAX);
+	char* msg = dyninput_str(maxsize);
+	if (!msg)
+	{
+		puts("ERROR: String input failed! Exiting...");
+		return -1;
+	}
 
 	fputs("Enter your key (shift value): ", stdout);
 	fgets(buf, 4, stdin);
@@ -41,18 +43,18 @@ int main()
 
 	if (choice == 1)
 	{
-		caesar_encrypt(msg, 128, key);
+		caesar_encrypt(msg, maxsize, key);
 		puts("\nYour encrypted message is:");
-		for (int i = 0; i < 128 && msg[i]; i++)
+		for (int i = 0; i < maxsize && msg[i]; i++)
 		{
 			putchar(msg[i]);
 		}
 	}
 	else if (choice == 2)
 	{
-		caesar_decrypt(msg, 128, key);
+		caesar_decrypt(msg, maxsize, key);
 		puts("\nYour decrypted message is:");
-		for (int i = 0; i < 128 && msg[i]; i++)
+		for (int i = 0; i < maxsize && msg[i]; i++)
 		{
 			putchar(msg[i]);
 		}

src/crypt.c

@@ -9,8 +9,16 @@
 */
 
 #include "crypt.h"
-#include <stdbool.h>
 
+#include <stdbool.h>
+#include <stdint.h>
+
+
+/* 
+  * For built in C mod operator (%) -1 % 26 == -1
+  * For the requirements of this algorithm -1 mod 26 == 25 is required
+  * The below functions accomplish this
+*/
 
 // Which of the two below functions is faster (find out!)
 inline int mod(int a, int b)
@@ -26,15 +34,20 @@ inline int fast_mod(int a, int b)
 }
 
 
+/*
+  * 65 - 90	 = ASCII 'A' - 'Z'
+  * 97 - 122 = ASCII 'a' - 'z'
+*/
+
 inline bool isupper(char c)
 {
 	return c >= 'A' && c <= 'Z';
 }
 
 
-void caesar_encrypt(char* str, int size, int key)
+void caesar_encrypt(char* str, int64_t size, int key)
 {
-	for (int i = 0; i < size && str[i] != '\n'; i++)
+	for (int64_t i = 0; i < size && str[i] != '\n'; i++)
 		if (str[i] != ' ')
 		{
 			bool upper = isupper(str[i]);
@@ -45,9 +58,9 @@ void caesar_encrypt(char* str, int size, int key)
 }
 
 
-void caesar_decrypt(char* str, int size, int key)
+void caesar_decrypt(char* str, int64_t size, int key)
 {
-	for (int i = 0; i < size && str[i] != '\n'; i++)
+	for (int64_t i = 0; i < size && str[i] != '\n'; i++)
 		if (str[i] != ' ')
 		{
 			bool upper = isupper(str[i]);

src/crypt.h

@@ -9,8 +9,9 @@
 */
 
 #pragma once
+#include <stdint.h>
 
 
-void caesar_encrypt(char* str, int size, int key);
+void caesar_encrypt(char* str, int64_t size, int key);
 
-void caesar_decrypt(char* str, int size, int key);
+void caesar_decrypt(char* str, int64_t size, int key);

src/dyninput.c

@@ -15,33 +15,44 @@
 
 char* dyninput_str(int_least64_t maxsize)
 {
-    char* str = malloc(3 * sizeof(char));
-    /*if (!str)
-        puts("Error allocating memory!");
-        return NULL;*/
+	char* str = malloc(3 * sizeof(char));
+	if (!str)
+	{
+		puts("\nError allocating memory!");
+		return NULL;
+	}
 
-    int_least64_t size = 3, i = 0;
-    char c = 0;
+	int_least64_t size = 3, i = 0;
+	char c = 0;
 
-    do
-    {
-        c = getchar();
-        if (i + 2 == size)
-        {
-            char* tmp = realloc(str, size + 1);
-            if (!tmp)
-            {
-                puts("Error (re)allocating memory!");
-                return NULL;
-            }
-            str = tmp;
-            size++;
-        }
+	do
+	{
+		if (size == maxsize)
+		{
+			printf("Character limit of %lld reached!\n", maxsize);
+			break;
+		}
 
-        str[i] = c;
-        i++;
-    } while (c && c != '\n');
-    str[i] = '\0';
+		c = (char)getchar();
+		if (i + 1 == size)
+		{
+			char* tmp = realloc(str, size + 1);
+			if (!tmp)
+			{
+				puts("Error (re)allocating memory!");
+				return NULL;
+			}
+			str = tmp;
+			size++;
+		}
 
-    return str;
+		str[i] = c;
+		i++;
+	} while (c && c != '\n');
+	if (str[i - 1] != '\n') str[i - 1] = '\n';
+	str[i] = '\0';
+
+	// Sanitise stdin
+	while (c != '\n') c = (char)getchar();
+	return str;
 }