moves out the file functions into their own file

src/Makefile

@@ -1,15 +1,16 @@
 TARGET=xxd
 CC=gcc
 
-OBJ = main.o hex.o
+OBJ = main.o hex.o file.o
 
 $(TARGET): $(OBJ)
 	mkdir -p ../build
 	$(CC) -Wall -g -o $(TARGET) $(OBJ) -g
 	mv $(TARGET) ../build/
 
-main.o: include/hex.h
+main.o: include/hex.h include/file.h
 hex.o: include/hex.h
+file.o: include/file.h
 
 .PHONY: clean
 clean:

src/file.c

@@ -0,0 +1,49 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "include/file.h"
+
+void read_file_to_buf(const char* filename, char** buf)
+{
+	FILE* f;
+	int err, bufsize, newlen;
+
+	f = fopen(filename, "r");
+	if (f == NULL) {
+		perror("fopen");
+		exit(EXIT_FAILURE);
+	}
+
+	err = fseek(f, 0L, SEEK_END);
+	if (err != 0) {
+		perror("fseek");
+		fclose(f);
+		exit(EXIT_FAILURE); }
+
+	bufsize = ftell(f);
+	if (bufsize == -1) {
+		perror("ftell");
+		fclose(f);
+		exit(EXIT_FAILURE);
+	}
+
+	(*buf) = malloc(sizeof(char) * (bufsize + 1));
+	if (*buf == NULL) {
+		perror("malloc");
+		fclose(f);
+		exit(EXIT_FAILURE);
+	}
+
+	rewind(f); 
+
+	newlen = fread(*buf, sizeof(char), bufsize, f);
+	if (ferror(f) != 0) {
+		perror("fread");
+		fclose(f);
+		exit(EXIT_FAILURE);
+	} else {
+		(*buf)[newlen++] = '\0'; // just to be safe	
+	}
+
+	fclose(f);
+}

src/include/file.h

@@ -0,0 +1,14 @@
+#ifndef FILE_H
+#define FILE_H
+
+/**
+ * read_file_to_buf
+ *
+ * - const char* filename - Name of the file we're opening
+ * - char** buf - pointer to the buffer to hold the file in
+ *
+ *   read the file into a buffer to prevent unnecessary file ops
+ */
+void read_file_to_buf(const char* filename, char** buf);
+
+#endif

src/main.c

@@ -3,59 +3,7 @@
 #include <string.h>
 
 #include "include/hex.h"
-
-/**
- * read_file_to_buf
- *
- * - const char* filename - Name of the file we're opening
- * - char** buf - pointer to the buffer to hold the file in
- *
- *   read the file into a buffer to prevent unnecessary file ops
- */
-void read_file_to_buf(const char* filename, char** buf)
-{
-	FILE* f;
-	int err, bufsize, newlen;
-
-	f = fopen(filename, "r");
-	if (f == NULL) {
-		perror("fopen");
-		exit(EXIT_FAILURE);
-	}
-
-	err = fseek(f, 0L, SEEK_END);
-	if (err != 0) {
-		perror("fseek");
-		fclose(f);
-		exit(EXIT_FAILURE); }
-
-	bufsize = ftell(f);
-	if (bufsize == -1) {
-		perror("ftell");
-		fclose(f);
-		exit(EXIT_FAILURE);
-	}
-
-	(*buf) = malloc(sizeof(char) * (bufsize + 1));
-	if (*buf == NULL) {
-		perror("malloc");
-		fclose(f);
-		exit(EXIT_FAILURE);
-	}
-
-	rewind(f); 
-
-	newlen = fread(*buf, sizeof(char), bufsize, f);
-	if (ferror(f) != 0) {
-		perror("fread");
-		fclose(f);
-		exit(EXIT_FAILURE);
-	} else {
-		(*buf)[newlen++] = '\0'; // just to be safe	
-	}
-
-	fclose(f);
-}
+#include "include/file.h"
 
 int get_hex_lines(int len)
 {