From 7f5df7b999d247198e0d6fa15e2d1ffd36318842 Mon Sep 17 00:00:00 2001
From: James Townsend <j.a.townsend2000@gmail.com>
Date: Mon, 21 Jun 2021 14:15:01 +0100
Subject: [PATCH] Separate enigma code from frontend

---
 Makefile   | 11 +++++++----
 enigma.c   | 46 +---------------------------------------------
 enigma.h   | 28 ++++++++++++++++++++++++++++
 frontend.c | 25 +++++++++++++++++++++++++
 4 files changed, 61 insertions(+), 49 deletions(-)
 create mode 100644 enigma.h
 create mode 100644 frontend.c

diff --git a/Makefile b/Makefile
index ed340e3..87ff7be 100644
--- a/Makefile
+++ b/Makefile
@@ -1,13 +1,16 @@
 OPTS := -Wall -pedantic -std=c11
 
-all: enigma
+all: frontend
 
 build/%.o: %.c
-	gcc $(OPTS) -c $< -g -o $@
+	gcc $(OPTS) -c $< -g -fpic -o $@
 
 
-enigma: build/enigma.o build/readlines.o build/rotor.o
-	gcc build/enigma.o build/readlines.o build/rotor.o -o build/enigma
+build/libenigma.so: build/enigma.o build/readlines.o build/rotor.o
+	gcc build/enigma.o build/readlines.o build/rotor.o -shared -o build/libenigma.so
+
+frontend: build/libenigma.so
+	gcc -Lbuild -Wl,-rpath=build -o build/enigma frontend.c -lenigma
 
 make clean:
 	rm -f build/*.o build/*.so build/enigma
\ No newline at end of file
diff --git a/enigma.c b/enigma.c
index 36e77c3..89935fa 100644
--- a/enigma.c
+++ b/enigma.c
@@ -1,50 +1,6 @@
 #include <stdlib.h>
 #include <stdio.h>
-#include "readlines.h"
-#include "rotor.h"
-
-struct enigma_structure {
-    rotor rotors[3];
-    rotor reflector;
-    char plugboard[27]; // Used to perform substitution
-    char pairs[30]; // Not needed for enigma functionality, but useful to output plugboard config
-};
-
-typedef struct enigma_structure *enigma;
-
-void keypress_rotate(rotor rotors[3]);
-char *encode_message(char *message, rotor rotors[3], rotor reflector, char plugboard[26]);
-char p_sub(char c, char p[26]);
-void input(char *string,int length);
-enigma create_enigma_from_file(FILE *config_file, r_template templates[], int num_templates);
-void destroy_engima(enigma e);
-void display_config(enigma e);
-r_template *load_templates_from_file(FILE* f, int *num_rotors);
-enigma create_enigma(r_template rotors[3], r_template reflector, char positions[3], char ring_settings[3], char plugboard[27], char pairs[30]);
-
-int main() {
-    FILE* file = fopen("rotors", "r");
-    int num_rotors = 0;
-    r_template *templates = load_templates_from_file(file, &num_rotors);
-    fclose(file);
-
-    FILE *config_file = fopen("config", "r");
-    enigma e = create_enigma_from_file(config_file, templates, num_rotors);
-    fclose(config_file);
-    free(templates);
-
-    display_config(e);
-
-    printf("Enter message to be encoded: ");
-    char buffer[BUFFER_SIZE];
-    input(buffer, BUFFER_SIZE);
-
-    char *result = encode_message(buffer, e->rotors, e->reflector, e->plugboard);
-
-    printf("Result: %s\n", result);
-    destroy_engima(e);
-    free(result);
-}
+#include "enigma.h"
 
 r_template *load_templates_from_file(FILE* f, int *num_rotors) {
     int arr_size = LINES_ARR_LEN;
diff --git a/enigma.h b/enigma.h
new file mode 100644
index 0000000..66bc276
--- /dev/null
+++ b/enigma.h
@@ -0,0 +1,28 @@
+#ifndef enigma_h
+
+#define enigma_h
+
+#include "rotor.h"
+#include "readlines.h"
+#include <stdio.h>
+
+struct enigma_structure {
+    rotor rotors[3];
+    rotor reflector;
+    char plugboard[27]; // Used to perform substitution
+    char pairs[30]; // Not needed for enigma functionality, but useful to output plugboard config
+};
+
+typedef struct enigma_structure *enigma;
+
+void keypress_rotate(rotor rotors[3]);
+char *encode_message(char *message, rotor rotors[3], rotor reflector, char plugboard[26]);
+char p_sub(char c, char p[26]);
+void input(char *string,int length);
+enigma create_enigma_from_file(FILE *config_file, r_template templates[], int num_templates);
+void destroy_engima(enigma e);
+void display_config(enigma e);
+r_template *load_templates_from_file(FILE* f, int *num_rotors);
+enigma create_enigma(r_template rotors[3], r_template reflector, char positions[3], char ring_settings[3], char plugboard[27], char pairs[30]);
+
+#endif
\ No newline at end of file
diff --git a/frontend.c b/frontend.c
new file mode 100644
index 0000000..fecb240
--- /dev/null
+++ b/frontend.c
@@ -0,0 +1,25 @@
+#include "enigma.h"
+
+int main() {
+    FILE* file = fopen("rotors", "r");
+    int num_rotors = 0;
+    r_template *templates = load_templates_from_file(file, &num_rotors);
+    fclose(file);
+
+    FILE *config_file = fopen("config", "r");
+    enigma e = create_enigma_from_file(config_file, templates, num_rotors);
+    fclose(config_file);
+    free(templates);
+
+    display_config(e);
+
+    printf("Enter message to be encoded: ");
+    char buffer[BUFFER_SIZE];
+    input(buffer, BUFFER_SIZE);
+
+    char *result = encode_message(buffer, e->rotors, e->reflector, e->plugboard);
+
+    printf("Result: %s\n", result);
+    destroy_engima(e);
+    free(result);
+}
\ No newline at end of file