some small fixes, and begining of reverse

src/hex.c

@@ -21,6 +21,8 @@ void init_flags(struct flags* flags)
 
 	flags->littleendian = false;
 
+	flags->reverse_op = false;
+
 	flags->octets = 2;
 	flags->customoctets = false;
 

src/include/hex.h

@@ -29,6 +29,8 @@ struct flags {
 
 	bool littleendian;
 
+	bool reverse_op;
+
 	uint offset;
 	int seek;
 	

src/main.c

@@ -25,6 +25,7 @@ static struct argp_option options[] = {
 	{0, 'o', "off", 0, "add <off> to the displayed file position.", 0},
 	{0, 'e', 0, 0, "little-endian dump (incompatible with -ps,-i,-r).", 0},
 	{0, 's', "seek", 0, "start at <[+][-] seek> bytes abs. infile offset.", 0},
+	{0, 'r', 0, 0, "reverse operation: convert (or patch) hexdump into binary.", 0},
 	{0}
 };
 
@@ -65,6 +66,9 @@ static error_t parse_opt(int key, char* arg, struct argp_state* state)
 			else
 			 	flags->coloured = true;
 			break;
+		case 'r':
+			flags->reverse_op = true;
+			flags->coloured = false;
 		case 'l':
 			flags->len = atoi(arg);
 			break;
@@ -126,11 +130,11 @@ static void do_text_parse(hex_chunk_t** lines, bool interactive)
 	}
 
 	if (flags.seek >= 0) {
-		if (flags.seek > strlen(file_content))
+		if (flags.seek > (int) strlen(file_content))
 			exit(EXIT_SUCCESS);
 		seek = flags.seek;
 	} else {
-		if ((flags.seek * -1) > strlen(file_content)) {
+		if ((flags.seek * -1) > (int) strlen(file_content)) {
 			fprintf(stderr, "xxd: Sorry, cannot seek.\n");
 			exit(EXIT_FAILURE);
 		}