Adds better file error handling

Creates a find id function

src/csv.c

@@ -9,7 +9,7 @@
 #include "json.h"
 #include "csv.h"
 
-#define MAX_BUFFER_SIZE 512
+#define MAX_BUFFER_SIZE 1024
 
 int get_next_id()
 {
@@ -31,6 +31,37 @@ int get_next_id()
 	return atoi(id) + 1;
 }
 
+long find_id(int id_to_find)
+{
+	FILE* csv;
+	char* buffer;
+	size_t line_size = MAX_BUFFER_SIZE - 1;
+	int i, file_exists;
+	long file_pos;
+
+
+	file_exists = access(FILE_NAME, F_OK);
+	if (0 != file_exists) {
+		fprintf(stderr, "%s does not exist!", FILE_NAME);
+		exit(EXIT_FAILURE);
+	}
+
+	csv = fopen(FILE_NAME, "r");
+	if (NULL == csv) {
+		fprintf(stderr, "Failed to open %s!\n", FILE_NAME);
+		exit(EXIT_FAILURE);
+	}
+
+	for(i = 0; i < id_to_find + 1; i++)
+		getline(&buffer, &line_size, csv);
+
+	file_pos = ftell(csv);
+	fclose(csv);
+
+	return file_pos;
+}
+
+
 void write_to_file(book_t* book)
 {
 	FILE* file;
@@ -52,6 +83,11 @@ void write_to_file(book_t* book)
 		book_id = get_next_id();
 	}
 
+	if (NULL == file) {
+		fprintf(stderr, "Failed to open %s!\n", FILE_NAME);
+		exit(EXIT_FAILURE);
+	}
+
 	// now we write the information
 	fprintf(file, "%d,\"%s\",\"%s\",\"%s\",\"%s\",%d,%d\n", 
 			book_id, book->isbn, book->title, book->authors, book->image_url, book->year_of_publication, book->page_len);

src/csv.h

@@ -7,4 +7,6 @@ int get_next_id();
 
 void write_to_file(book_t* book);
 
+long find_id(int id_to_find);
+
 #endif

src/main.c

@@ -80,6 +80,8 @@ void process_args(char* argv[])
 
 int main(int argc, char* argv[])
 {
+	return 0;
+	
 	if (1 == argc) {
 		printf("Not enough arguments! Try typing %s --help\n", argv[0]);
 		return EXIT_FAILURE;