diff --git a/backend/2of5.c b/backend/2of5.c
index f917ccd5..94b9dee9 100644
--- a/backend/2of5.c
+++ b/backend/2of5.c
@@ -44,7 +44,7 @@ int matrix_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 80) {
+	if(ustrlen(source) > 80) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -57,7 +57,7 @@ int matrix_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	/* start character */
 	concat (dest, "411111");
 
-	for(i = 0; i <= strlen(source); i++) {
+	for(i = 0; i <= ustrlen(source); i++) {
 		lookup(NESET, C25MatrixTable, source[i], dest);
 	}
 
@@ -78,7 +78,7 @@ int industrial_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 45) {
+	if(ustrlen(source) > 45) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -91,7 +91,7 @@ int industrial_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	/* start character */
 	concat (dest, "313111");
 
-	for(i = 0; i <= strlen(source); i++) {
+	for(i = 0; i <= ustrlen(source); i++) {
 		lookup(NESET, C25IndustTable, source[i], dest);
 	}
 
@@ -111,7 +111,7 @@ int iata_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 45) {
+	if(ustrlen(source) > 45) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -124,7 +124,7 @@ int iata_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	/* start */
 	concat (dest, "1111");
 	
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		lookup(NESET, C25IndustTable, source[i], dest);
 	}
 	
@@ -145,7 +145,7 @@ int logic_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 80) {
+	if(ustrlen(source) > 80) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -158,7 +158,7 @@ int logic_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	/* start character */
 	concat (dest, "1111");
 
-	for(i = 0; i <= strlen(source); i++) {
+	for(i = 0; i <= ustrlen(source); i++) {
 		lookup(NESET, C25MatrixTable, source[i], dest);
 	}
 
@@ -179,7 +179,7 @@ int interleaved_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 90) {
+	if(ustrlen(source) > 90) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -191,13 +191,13 @@ int interleaved_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	
 	/* Input must be an even number of characters for Interlaced 2 of 5 to work:
 	   if an odd number of characters has been entered then add a leading zero */
-	if ((strlen(source)%2) != 0)
+	if ((ustrlen(source)%2) != 0)
 	{
 		/* there are an odd number of input characters */
 		unsigned int length;
 		char temp[100];
 
-		length = strlen(source);
+		length = ustrlen(source);
 
 		strcpy(temp, source);
 		source[0] = '0';
@@ -211,7 +211,7 @@ int interleaved_two_of_five(struct zint_symbol *symbol, unsigned char source[])
 	/* start character */
 	concat(dest, "1111");
 
-	for(i = 0; i < strlen(source); i+=2 )
+	for(i = 0; i < ustrlen(source); i+=2 )
 	{
 		/* look up the bars and the spaces and put them in two strings */
 		strcpy(bars, "");
@@ -247,7 +247,7 @@ int itf14(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 
 	count = 0;
-	h = strlen(source);
+	h = ustrlen(source);
 	
 	if(h != 13) {
 		strcpy(symbol->errtxt, "error: input wrong length");
@@ -287,7 +287,7 @@ int dpleit(struct zint_symbol *symbol, unsigned char source[])
 
 	error_number = 0;
 	count = 0;
-	h = strlen(source);
+	h = ustrlen(source);
 	if(h != 13) {
 		strcpy(symbol->errtxt, "error: input wrong length");
 		return ERROR_TOO_LONG;
@@ -322,7 +322,7 @@ int dpident(struct zint_symbol *symbol, unsigned char source[])
 	unsigned int h, count, check_digit;
 
 	count = 0;
-	h = strlen(source);
+	h = ustrlen(source);
 	if(h != 11) {
 		strcpy(symbol->errtxt, "erro: input wrong length");
 		return ERROR_TOO_LONG;
diff --git a/backend/auspost.c b/backend/auspost.c
index 8bded24f..f820dbf6 100644
--- a/backend/auspost.c
+++ b/backend/auspost.c
@@ -118,7 +118,7 @@ int australia_post(struct zint_symbol *symbol, unsigned char source[])
 	/* Do all of the length checking first to avoid stack smashing */
 	if(symbol->symbology == BARCODE_AUSPOST) {
 		/* Format control code (FCC) */
-		switch(strlen(source))
+		switch(ustrlen(source))
 		{
 			case 8: strcpy(fcc, "11"); break;
 			case 13: strcpy(fcc, "59"); break;
@@ -134,7 +134,7 @@ int australia_post(struct zint_symbol *symbol, unsigned char source[])
 			return errno;
 		}
 	} else {
-		if(strlen(source) != 8) {
+		if(ustrlen(source) != 8) {
 			strcpy(symbol->errtxt, "error: auspost input is wrong length");
 			return ERROR_TOO_LONG;
 		}
@@ -181,15 +181,15 @@ int australia_post(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 	/* Customer Information */
-	if(strlen(source) > 8)
+	if(ustrlen(source) > 8)
 	{
-		if((strlen(source) == 13) || (strlen(source) == 18)) {
-			for(reader = 8; reader < strlen(source); reader++) {
+		if((ustrlen(source) == 13) || (ustrlen(source) == 18)) {
+			for(reader = 8; reader < ustrlen(source); reader++) {
 				lookup(GDSET, AusCTable, source[reader], data_pattern);
 			}
 		}
-		if((strlen(source) == 16) || (strlen(source) == 23)) {
-			for(reader = 8; reader < strlen(source); reader++) {
+		if((ustrlen(source) == 16) || (ustrlen(source) == 23)) {
+			for(reader = 8; reader < ustrlen(source); reader++) {
 				lookup(NESET, AusNTable, source[reader], data_pattern);
 			}
 		}
diff --git a/backend/aztec.c b/backend/aztec.c
index 26a8e584..2763c97e 100644
--- a/backend/aztec.c
+++ b/backend/aztec.c
@@ -48,14 +48,14 @@ void insert(char binary_string[], int posn, char newbit)
 
 int aztec_text_process(unsigned char source[], char binary_string[])
 { /* Encode input data into a binary string */
-	int map_posn, i, j, k, bytes;
-	int charmap[strlen(source)], typemap[strlen(source)], maplength;
+	int i, j, k, bytes;
+	int charmap[ustrlen(source)], typemap[ustrlen(source)], maplength;
 	int curtable, newtable, lasttable, chartype;
-	int blockmap[2][strlen(source)], blocks;
+	int blockmap[2][ustrlen(source)], blocks;
 	
 	
 	/* Lookup input string in encoding table */
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if(source[i] > 127) {
 			charmap[i] = source[i];
 			typemap[i] = BINARY;
@@ -64,7 +64,7 @@ int aztec_text_process(unsigned char source[], char binary_string[])
 			typemap[i] = AztecCodeSet[source[i]];
 		}
 	}
-	maplength = strlen(source);
+	maplength = ustrlen(source);
 	
 	/* Look for double character encoding possibilities */
 	i = 0;
@@ -151,7 +151,6 @@ int aztec_text_process(unsigned char source[], char binary_string[])
 	}
 	
 	/* Combine blocks of the same type */
-	blocks;
 	i = 0;
 	do{
 		if(blockmap[0][i] == blockmap[0][i + 1]) {
diff --git a/backend/blockf.c b/backend/blockf.c
index 238fe611..ef588f4d 100644
--- a/backend/blockf.c
+++ b/backend/blockf.c
@@ -66,7 +66,8 @@ int a3_convert(unsigned char source) {
 	if(source < 32) { return source + 64; }
 	if((source >= 32) && (source <= 127)) { return source - 32; }
 	if((source >= 128) && (source <= 159)) { return (source - 128) + 64; }
-	if(source >= 160) { return (source - 128) - 32; }
+	/* if source >= 160 */
+	return (source - 128) - 32;
 }
 
 int character_subset_select(unsigned char source[], int input_position) {
@@ -92,14 +93,14 @@ int character_subset_select(unsigned char source[], int input_position) {
 
 int data_encode_blockf(unsigned char source[], int subset_selector[], int blockmatrix[][62], int *columns_needed, int *rows_needed, int *final_mode)
 {
-	int i, j, input_position, input_length, current_mode, current_row, error_number;
+	int i, input_position, input_length, current_mode, current_row, error_number;
 	int column_position, c, done, exit_status;
 	
 	error_number = 0;
 	exit_status = 0;
 	current_row = 0;
 	current_mode = MODEA;
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 	column_position = 0;
 	input_position = 0;
 	done = 0;
@@ -146,7 +147,7 @@ int data_encode_blockf(unsigned char source[], int subset_selector[], int blockm
 							column_position++;
 							c--;
 						}
-						done == 1;
+						done = 1;
 					}
 					
 					if((source[input_position] >= 128) && (done == 0)) {
@@ -186,7 +187,7 @@ int data_encode_blockf(unsigned char source[], int subset_selector[], int blockm
 							column_position++;
 							c--;
 						}
-						done == 1;
+						done = 1;
 					}
 					
 					if((source[input_position] >= 160) && (done == 0)) {
@@ -532,7 +533,7 @@ int codablock(struct zint_symbol *symbol, unsigned char source[])
 	int k1_check, k2_check;
 	
 	error_number = 0;
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 	final_mode = MODEA;
 	
 	if(input_length > 5450) {
diff --git a/backend/code.c b/backend/code.c
index 4cbe2296..ca8ce69f 100644
--- a/backend/code.c
+++ b/backend/code.c
@@ -86,7 +86,7 @@ int code_11(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 80) {
+	if(ustrlen(source) > 80) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -104,13 +104,13 @@ int code_11(struct zint_symbol *symbol, unsigned char source[])
 	concat (dest, "112211");
 
 	/* Draw main body of barcode */
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		lookup(NASET, C11Table, source[i], dest);
 		weight[i] = ctoi(source[i]);
 	}
 
 	/* Calculate C checksum */
-	for(h = (strlen(source) - 1); h >= 0; h--) {
+	for(h = (ustrlen(source) - 1); h >= 0; h--) {
 		c_count += (c_weight * weight[h]);
 		c_weight++;
 
@@ -122,10 +122,10 @@ int code_11(struct zint_symbol *symbol, unsigned char source[])
 
 	/* Draw C checksum */
 	lookup(NASET, C11Table, itoc(c_digit), dest);
-	weight[strlen(source)] = c_digit;
+	weight[ustrlen(source)] = c_digit;
 
 	/* Calculate K checksum */
-	for(h = strlen(source); h >= 0; h--) {
+	for(h = ustrlen(source); h >= 0; h--) {
 		k_count += (k_weight * weight[h]);
 		k_weight++;
 
@@ -141,7 +141,7 @@ int code_11(struct zint_symbol *symbol, unsigned char source[])
 	/* Stop character */
 	concat (dest, "11221");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(c_digit);
 	source[h + 1] = itoc(k_digit);
 	source[h + 2] = '\0';
@@ -167,7 +167,7 @@ int c39(struct zint_symbol *symbol, unsigned char source[])
 	}
 	
 	to_upper(source);
-	if(strlen(source) > 45) {
+	if(ustrlen(source) > 45) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -180,7 +180,7 @@ int c39(struct zint_symbol *symbol, unsigned char source[])
 	/* Start character */
 	concat(dest, "1211212111");
 
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		lookup(TCSET, C39Table, source[i], dest);
 		counter += posn(TCSET, source[i]);
 	}
@@ -212,7 +212,7 @@ int c39(struct zint_symbol *symbol, unsigned char source[])
 			check_digit = '_';
 		}
 		
-		h = strlen(source);
+		h = ustrlen(source);
 		source[h] = check_digit;
 		source[h + 1] = '\0';
 	}
@@ -250,7 +250,7 @@ int pharmazentral(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 
 	count = 0;
-	h = strlen(source);
+	h = ustrlen(source);
 	if(h != 6) {
 		strcpy(symbol->errtxt, "error: input wrong length");
 		return ERROR_TOO_LONG;
@@ -295,7 +295,7 @@ int ec39(struct zint_symbol *symbol, unsigned char source[])
 	
 	error_number = 0;
 
-	if(strlen(source) > 45) {
+	if(ustrlen(source) > 45) {
 		/* only stops strings which are far too long - actual length of the barcode
 		depends on the type of data being encoded - if it's too long it's picked up
 		by c39() */
@@ -304,7 +304,7 @@ int ec39(struct zint_symbol *symbol, unsigned char source[])
 	}
 	
 	
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if(source[i] > 127) {
 			/* Cannot encode extended ASCII */
 			strcpy(symbol->errtxt, "error: invalid characters in input data");
@@ -313,7 +313,7 @@ int ec39(struct zint_symbol *symbol, unsigned char source[])
 	}
 	
 	/* Creates a buffer string and places control characters into it */
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		ascii_value = source[i];
 		concat(buffer, EC39Ctrl[ascii_value]);
 	}
@@ -345,14 +345,14 @@ int c93(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 45) {
+	if(ustrlen(source) > 45) {
 		/* This stops rediculously long input - the actual length of the barcode
 		depends on the type of data */
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
 	
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if(source[i] > 127) {
 			/* Cannot encode extended ASCII */
 			strcpy(symbol->errtxt, "error: invalid characters in input data");
@@ -364,7 +364,7 @@ int c93(struct zint_symbol *symbol, unsigned char source[])
 	concat(dest, "111141");
 
 	/* Message Content */
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		ascii_value = source[i];
 		concat(buffer, C93Ctrl[ascii_value]);
 	}
@@ -429,7 +429,7 @@ int c93(struct zint_symbol *symbol, unsigned char source[])
 	/* Stop character */
 	concat(dest, "1111411");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = set_copy[c];
 	source[h + 1] = set_copy[k];
 	source[h + 2] = '\0';
diff --git a/backend/code128.c b/backend/code128.c
index 821628d2..f247b55a 100644
--- a/backend/code128.c
+++ b/backend/code128.c
@@ -194,7 +194,7 @@ int code_128(struct zint_symbol *symbol, unsigned char source[])
 	errornum = 0;
 	strcpy(dest, "");
 	
-	sourcelen = strlen(source);
+	sourcelen = ustrlen(source);
 	
 	j = 0;
 	e_count = 0;
@@ -582,7 +582,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[])
 	errornum = 0;
 	strcpy(dest, "");
 	linkage_flag = 0;
-	sourcelen = strlen(source);
+	sourcelen = ustrlen(source);
 
 	j = 0;
 	e_count = 0;
@@ -907,7 +907,7 @@ int ean_14(struct zint_symbol *symbol, unsigned char source[])
 	char ean128_equiv[20];
 	
 	strcpy(ean128_equiv, "");
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 	
 	if(input_length != 13) {
 		strcpy(symbol->errtxt, "error: input wrong length");
diff --git a/backend/code16k.c b/backend/code16k.c
index c1905c81..840eec19 100644
--- a/backend/code16k.c
+++ b/backend/code16k.c
@@ -121,7 +121,7 @@ int code16k(struct zint_symbol *symbol, unsigned char source[])
 	int input_length;
 
 	errornum = 0;
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 	
 	if(input_length > 157) {
 		strcpy(symbol->errtxt, "error: input too long");
@@ -391,7 +391,7 @@ int code16k(struct zint_symbol *symbol, unsigned char source[])
 				read += 2;
 				break;
 		}
-	} while (read < strlen(source));
+	} while (read < ustrlen(source));
 
 	
 	pads_needed = 5 - ((bar_characters + 2) % 5);
diff --git a/backend/common.c b/backend/common.c
index 681af707..534c1bca 100644
--- a/backend/common.c
+++ b/backend/common.c
@@ -25,6 +25,16 @@
 
 #define SSET	"0123456789ABCDEF"
 
+int ustrlen(unsigned char data[]) {
+	/* Local replacement for strlen() with unsigned char strings */
+	int i;
+	
+	i = -1;
+	do { i++; } while (data[i] != '\0');
+
+	return i;
+}
+
 void concat(char dest[], char source[])
 { /* Concatinates dest[] with the contents of source[], copying /0 as well */
 	unsigned int i, j;
@@ -53,7 +63,7 @@ void to_upper(unsigned char source[])
 { /* Converts lower case characters to upper case in a string source[] */
 	unsigned int i;
 
-	for (i = 0; i < strlen(source); i++) {
+	for (i = 0; i < ustrlen(source); i++) {
 		if ((source[i] >= 'a') && (source[i] <= 'z')) {
 			source [i] = (source[i] - 'a') + 'A'; }
 	}
@@ -63,7 +73,7 @@ int is_sane(char test_string[], unsigned char source[])
 { /* Verifies that a string only uses valid characters */
 	unsigned int i, j, latch;
 
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		latch = FALSE;
 		for(j = 0; j < strlen(test_string); j++) {
 			if (source[i] == test_string[j]) { latch = TRUE; } }
diff --git a/backend/common.h b/backend/common.h
index 40621aa2..dfabbeba 100644
--- a/backend/common.h
+++ b/backend/common.h
@@ -28,6 +28,7 @@
 
 #include "zint.h"
 
+int ustrlen(unsigned char source[]);
 void concat(char dest[], char source[]);
 int ctoi(char source);
 char itoc(int source);
diff --git a/backend/composite.c b/backend/composite.c
index 6246e084..d620487c 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -109,7 +109,6 @@ int encode928(UINT bitString[], UINT codeWords[], int bitLng) {
 
 int cc_a(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 { /* CC-A 2D component */
-	int temp;
 	int i, strpos, segment, bitlen, cwCnt, variant, rows;
 	int k, offset, j, total, rsCodeWords[8];
 	int LeftRAPStart, RightRAPStart, CentreRAPStart, StartCluster;
@@ -122,7 +121,7 @@ int cc_a(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 	for(i = 0; i < 13; i++) { bitStr[i] = 0; }
 	for(i = 0; i < 28; i++) { codeWords[i] = 0; }
 	
-	bitlen = strlen(source);
+	bitlen = ustrlen(source);
 	
 	for(i = bitlen; i < 197; i++) {
 		source[i] = '0';
@@ -322,7 +321,7 @@ int cc_a(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 int cc_b(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 { /* CC-B 2D component */
 	int length, i, binloc;
-	unsigned char data_string[(strlen(source) / 8) + 3];
+	unsigned char data_string[(ustrlen(source) / 8) + 3];
 	int chainemc[180], mclength;
 	int k, j, longueur, mccorrection[50], offset;
 	int total, dummy[5];
@@ -330,7 +329,7 @@ int cc_b(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 	int variant, LeftRAPStart, CentreRAPStart, RightRAPStart, StartCluster;
 	int LeftRAP, CentreRAP, RightRAP, Cluster, writer, flip, loop;
 	
-	length = strlen(source) / 8;
+	length = ustrlen(source) / 8;
 	
 	for(i = 0; i < length; i++) {
 		binloc = i * 8;
@@ -549,13 +548,13 @@ int cc_b(struct zint_symbol *symbol, unsigned char source[], int cc_width)
 int cc_c(struct zint_symbol *symbol, unsigned char source[], int cc_width, int ecc_level)
 { /* CC-C 2D component - byte compressed PDF417 */
 	int length, i, binloc;
-	unsigned char data_string[(strlen(source) / 8) + 4];
+	unsigned char data_string[(ustrlen(source) / 8) + 4];
 	int chainemc[1000], mclength, k;
 	int offset, longueur, loop, total, j, mccorrection[520];
 	int c1, c2, c3, dummy[35];
 	char codebarre[100], pattern[580];
 	
-	length = strlen(source) / 8;
+	length = ustrlen(source) / 8;
 	
 	for(i = 0; i < length; i++) {
 		binloc = i * 8;
@@ -689,9 +688,9 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 { /* Handles all data encodation from section 5 of ISO/IEC 24723 */
 	int encoding_method, read_posn, d1, d2, value, alpha_pad;
 	int group_val, i, j, mask, ai_crop, ai_crop_posn, fnc1_latch;
-	int ai90_mode, latch, remainder;
+	int ai90_mode, latch, remainder, binary_length;
 	char date_str[4];
-	char general_field[strlen(source)], general_field_type[strlen(source)];
+	char general_field[ustrlen(source)], general_field_type[ustrlen(source)];
 	int target_bitsize;
 	
 	encoding_method = 1;
@@ -703,7 +702,7 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 	ai90_mode = 0;
 	*(ecc) = 0;
 	
-	if((source[0] == '1') && ((source[1] == '0') || (source[1] == '1') || (source[1] == '7')) && (strlen(source) > 8)) {
+	if((source[0] == '1') && ((source[1] == '0') || (source[1] == '1') || (source[1] == '7')) && (ustrlen(source) > 8)) {
 		/* Source starts (10), (11) or (17) */
 		encoding_method = 2;
 	}
@@ -772,8 +771,8 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 
 	if (encoding_method == 3) {
 		/* Encodation Method field of "11" - AI 90 */
-		char ninety[strlen(source)], numeric_part[4];
-		int alpha, alphanum, numeric, test1, test2, test3, next_ai_posn, test4;
+		char ninety[ustrlen(source)], numeric_part[4];
+		int alpha, alphanum, numeric, test1, test2, test3, next_ai_posn;
 		int numeric_value, table3_letter, mask;
 		
 		/* "This encodation method may be used if an element string with an AI
@@ -785,7 +784,7 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		do {
 			ninety[i] = source[i + 2];
 			i++;
-		} while ((source[i + 2] != '[') && ((i + 2) < strlen(source)));
+		} while ((source[i + 2] != '[') && ((i + 2) < ustrlen(source)));
 		ninety[i] = '\0';
 		
 		/* Find out if the AI 90 data is alphabetic or numeric or both */
@@ -1071,7 +1070,7 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		j++;
 	}
 	
-	for(i = read_posn; i < strlen(source); i++) {
+	for(i = read_posn; i < ustrlen(source); i++) {
 		general_field[j] = source[i];
 		j++;
 	}
@@ -1334,34 +1333,35 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		}
 	} while (i + latch < strlen(general_field));
 
+	binary_length = strlen(binary_string);
 	if(cc_mode == 1) {
 		/* CC-A 2D component - calculate remaining space */
 		switch(*(cc_width)) {
 			case 2:
-				if(strlen(binary_string) > 167) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 118) { target_bitsize = 118; }
-				if(strlen(binary_string) <= 108) { target_bitsize = 108; }
-				if(strlen(binary_string) <= 88) { target_bitsize = 88; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
-				if(strlen(binary_string) <= 59) { target_bitsize = 59; }
+				if(binary_length > 167) { return ERROR_TOO_LONG; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 118) { target_bitsize = 118; }
+				if(binary_length <= 108) { target_bitsize = 108; }
+				if(binary_length <= 88) { target_bitsize = 88; }
+				if(binary_length <= 78) { target_bitsize = 78; }
+				if(binary_length <= 59) { target_bitsize = 59; }
 				break;
 			case 3:
-				if(strlen(binary_string) > 167) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 118) { target_bitsize = 118; }
-				if(strlen(binary_string) <= 98) { target_bitsize = 98; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
+				if(binary_length > 167) { return ERROR_TOO_LONG; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 118) { target_bitsize = 118; }
+				if(binary_length <= 98) { target_bitsize = 98; }
+				if(binary_length <= 78) { target_bitsize = 78; }
 				break;
 			case 4:
-				if(strlen(binary_string) > 197) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 197) { target_bitsize = 197; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 108) { target_bitsize = 108; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
+				if(binary_length > 197) { return ERROR_TOO_LONG; }
+				if(binary_length <= 197) { target_bitsize = 197; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 108) { target_bitsize = 108; }
+				if(binary_length <= 78) { target_bitsize = 78; }
 				break;
 		}
 	}
@@ -1370,41 +1370,41 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		/* CC-B 2D component - calculated from ISO/IEC 24728 Table 1  */
 		switch(*(cc_width)) {
 			case 2:
-				if(strlen(binary_string) > 336) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 336) { target_bitsize = 336; }
-				if(strlen(binary_string) <= 296) { target_bitsize = 296; }
-				if(strlen(binary_string) <= 256) { target_bitsize = 256; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 160) { target_bitsize = 160; }
-				if(strlen(binary_string) <= 104) { target_bitsize = 104; }
-				if(strlen(binary_string) <= 56) { target_bitsize = 56; }
+				if(binary_length > 336) { return ERROR_TOO_LONG; }
+				if(binary_length <= 336) { target_bitsize = 336; }
+				if(binary_length <= 296) { target_bitsize = 296; }
+				if(binary_length <= 256) { target_bitsize = 256; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 160) { target_bitsize = 160; }
+				if(binary_length <= 104) { target_bitsize = 104; }
+				if(binary_length <= 56) { target_bitsize = 56; }
 				break;
 			case 3:
-				if(strlen(binary_string) > 768) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 768) { target_bitsize = 768; }
-				if(strlen(binary_string) <= 648) { target_bitsize = 648; }
-				if(strlen(binary_string) <= 536) { target_bitsize = 536; }
-				if(strlen(binary_string) <= 416) { target_bitsize = 416; }
-				if(strlen(binary_string) <= 304) { target_bitsize = 304; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 152) { target_bitsize = 152; }
-				if(strlen(binary_string) <= 112) { target_bitsize = 112; }
-				if(strlen(binary_string) <= 72) { target_bitsize = 72; }
-				if(strlen(binary_string) <= 32) { target_bitsize = 32; }
+				if(binary_length > 768) { return ERROR_TOO_LONG; }
+				if(binary_length <= 768) { target_bitsize = 768; }
+				if(binary_length <= 648) { target_bitsize = 648; }
+				if(binary_length <= 536) { target_bitsize = 536; }
+				if(binary_length <= 416) { target_bitsize = 416; }
+				if(binary_length <= 304) { target_bitsize = 304; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 152) { target_bitsize = 152; }
+				if(binary_length <= 112) { target_bitsize = 112; }
+				if(binary_length <= 72) { target_bitsize = 72; }
+				if(binary_length <= 32) { target_bitsize = 32; }
 				break;
 			case 4:
-				if(strlen(binary_string) > 1184) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 1184) { target_bitsize = 1184; }
-				if(strlen(binary_string) <= 1016) { target_bitsize = 1016; }
-				if(strlen(binary_string) <= 840) { target_bitsize = 840; }
-				if(strlen(binary_string) <= 672) { target_bitsize = 672; }
-				if(strlen(binary_string) <= 496) { target_bitsize = 496; }
-				if(strlen(binary_string) <= 352) { target_bitsize = 352; }
-				if(strlen(binary_string) <= 264) { target_bitsize = 264; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 152) { target_bitsize = 152; }
-				if(strlen(binary_string) <= 96) { target_bitsize = 96; }
-				if(strlen(binary_string) <= 56) { target_bitsize = 56; }
+				if(binary_length > 1184) { return ERROR_TOO_LONG; }
+				if(binary_length <= 1184) { target_bitsize = 1184; }
+				if(binary_length <= 1016) { target_bitsize = 1016; }
+				if(binary_length <= 840) { target_bitsize = 840; }
+				if(binary_length <= 672) { target_bitsize = 672; }
+				if(binary_length <= 496) { target_bitsize = 496; }
+				if(binary_length <= 352) { target_bitsize = 352; }
+				if(binary_length <= 264) { target_bitsize = 264; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 152) { target_bitsize = 152; }
+				if(binary_length <= 96) { target_bitsize = 96; }
+				if(binary_length <= 56) { target_bitsize = 56; }
 				break;
 		}
 	}
@@ -1414,8 +1414,8 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		int byte_length, codewords_used, ecc_level, ecc_codewords, rows;
 		int codewords_total, target_codewords, target_bytesize;
 		
-		byte_length = strlen(binary_string) / 8;
-		if(strlen(binary_string) % 8 != 0) { byte_length++; }
+		byte_length = binary_length / 8;
+		if(binary_length % 8 != 0) { byte_length++; }
 		
 		codewords_used = (byte_length / 6) * 5;
 		codewords_used += byte_length % 6;
@@ -1461,7 +1461,7 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		target_bitsize = 8 * target_bytesize;
 	}
 	
-	remainder = strlen(binary_string) - target_bitsize;
+	remainder = binary_length - target_bitsize;
 	
 	if(latch == 1) {
 		i = 0;
@@ -1507,34 +1507,35 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 	/* all the code below is repeated from above - it needs to be calculated again because the
 	   size of the symbol may have changed when adding data in the above sequence */
 	
+	binary_length = strlen(binary_string);
 	if(cc_mode == 1) {
 		/* CC-A 2D component - calculate padding required */
 		switch(*(cc_width)) {
 			case 2:
-				if(strlen(binary_string) > 167) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 118) { target_bitsize = 118; }
-				if(strlen(binary_string) <= 108) { target_bitsize = 108; }
-				if(strlen(binary_string) <= 88) { target_bitsize = 88; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
-				if(strlen(binary_string) <= 59) { target_bitsize = 59; }
+				if(binary_length > 167) { return ERROR_TOO_LONG; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 118) { target_bitsize = 118; }
+				if(binary_length <= 108) { target_bitsize = 108; }
+				if(binary_length <= 88) { target_bitsize = 88; }
+				if(binary_length <= 78) { target_bitsize = 78; }
+				if(binary_length <= 59) { target_bitsize = 59; }
 				break;
 			case 3:
-				if(strlen(binary_string) > 167) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 118) { target_bitsize = 118; }
-				if(strlen(binary_string) <= 98) { target_bitsize = 98; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
+				if(binary_length > 167) { return ERROR_TOO_LONG; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 118) { target_bitsize = 118; }
+				if(binary_length <= 98) { target_bitsize = 98; }
+				if(binary_length <= 78) { target_bitsize = 78; }
 				break;
 			case 4:
-				if(strlen(binary_string) > 197) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 197) { target_bitsize = 197; }
-				if(strlen(binary_string) <= 167) { target_bitsize = 167; }
-				if(strlen(binary_string) <= 138) { target_bitsize = 138; }
-				if(strlen(binary_string) <= 108) { target_bitsize = 108; }
-				if(strlen(binary_string) <= 78) { target_bitsize = 78; }
+				if(binary_length > 197) { return ERROR_TOO_LONG; }
+				if(binary_length <= 197) { target_bitsize = 197; }
+				if(binary_length <= 167) { target_bitsize = 167; }
+				if(binary_length <= 138) { target_bitsize = 138; }
+				if(binary_length <= 108) { target_bitsize = 108; }
+				if(binary_length <= 78) { target_bitsize = 78; }
 				break;
 		}
 	}
@@ -1543,41 +1544,41 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		/* CC-B 2D component */
 		switch(*(cc_width)) {
 			case 2:
-				if(strlen(binary_string) > 336) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 336) { target_bitsize = 336; }
-				if(strlen(binary_string) <= 296) { target_bitsize = 296; }
-				if(strlen(binary_string) <= 256) { target_bitsize = 256; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 160) { target_bitsize = 160; }
-				if(strlen(binary_string) <= 104) { target_bitsize = 104; }
-				if(strlen(binary_string) <= 56) { target_bitsize = 56; }
+				if(binary_length > 336) { return ERROR_TOO_LONG; }
+				if(binary_length <= 336) { target_bitsize = 336; }
+				if(binary_length <= 296) { target_bitsize = 296; }
+				if(binary_length <= 256) { target_bitsize = 256; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 160) { target_bitsize = 160; }
+				if(binary_length <= 104) { target_bitsize = 104; }
+				if(binary_length <= 56) { target_bitsize = 56; }
 				break;
 			case 3:
-				if(strlen(binary_string) > 768) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 768) { target_bitsize = 768; }
-				if(strlen(binary_string) <= 648) { target_bitsize = 648; }
-				if(strlen(binary_string) <= 536) { target_bitsize = 536; }
-				if(strlen(binary_string) <= 416) { target_bitsize = 416; }
-				if(strlen(binary_string) <= 304) { target_bitsize = 304; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 152) { target_bitsize = 152; }
-				if(strlen(binary_string) <= 112) { target_bitsize = 112; }
-				if(strlen(binary_string) <= 72) { target_bitsize = 72; }
-				if(strlen(binary_string) <= 32) { target_bitsize = 32; }
+				if(binary_length > 768) { return ERROR_TOO_LONG; }
+				if(binary_length <= 768) { target_bitsize = 768; }
+				if(binary_length <= 648) { target_bitsize = 648; }
+				if(binary_length <= 536) { target_bitsize = 536; }
+				if(binary_length <= 416) { target_bitsize = 416; }
+				if(binary_length <= 304) { target_bitsize = 304; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 152) { target_bitsize = 152; }
+				if(binary_length <= 112) { target_bitsize = 112; }
+				if(binary_length <= 72) { target_bitsize = 72; }
+				if(binary_length <= 32) { target_bitsize = 32; }
 				break;
 			case 4:
-				if(strlen(binary_string) > 1184) { return ERROR_TOO_LONG; }
-				if(strlen(binary_string) <= 1184) { target_bitsize = 1184; }
-				if(strlen(binary_string) <= 1016) { target_bitsize = 1016; }
-				if(strlen(binary_string) <= 840) { target_bitsize = 840; }
-				if(strlen(binary_string) <= 672) { target_bitsize = 672; }
-				if(strlen(binary_string) <= 496) { target_bitsize = 496; }
-				if(strlen(binary_string) <= 352) { target_bitsize = 352; }
-				if(strlen(binary_string) <= 264) { target_bitsize = 264; }
-				if(strlen(binary_string) <= 208) { target_bitsize = 208; }
-				if(strlen(binary_string) <= 152) { target_bitsize = 152; }
-				if(strlen(binary_string) <= 96) { target_bitsize = 96; }
-				if(strlen(binary_string) <= 56) { target_bitsize = 56; }
+				if(binary_length > 1184) { return ERROR_TOO_LONG; }
+				if(binary_length <= 1184) { target_bitsize = 1184; }
+				if(binary_length <= 1016) { target_bitsize = 1016; }
+				if(binary_length <= 840) { target_bitsize = 840; }
+				if(binary_length <= 672) { target_bitsize = 672; }
+				if(binary_length <= 496) { target_bitsize = 496; }
+				if(binary_length <= 352) { target_bitsize = 352; }
+				if(binary_length <= 264) { target_bitsize = 264; }
+				if(binary_length <= 208) { target_bitsize = 208; }
+				if(binary_length <= 152) { target_bitsize = 152; }
+				if(binary_length <= 96) { target_bitsize = 96; }
+				if(binary_length <= 56) { target_bitsize = 56; }
 				break;
 		}
 	}
@@ -1587,8 +1588,8 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		int byte_length, codewords_used, ecc_level, ecc_codewords, rows;
 		int codewords_total, target_codewords, target_bytesize;
 		
-		byte_length = strlen(binary_string) / 8;
-		if(strlen(binary_string) % 8 != 0) { byte_length++; }
+		byte_length = binary_length / 8;
+		if(binary_length % 8 != 0) { byte_length++; }
 		
 		codewords_used = (byte_length / 6) * 5;
 		codewords_used += byte_length % 6;
@@ -1634,7 +1635,7 @@ int cc_binary_string(struct zint_symbol *symbol, unsigned char source[], char bi
 		target_bitsize = 8 * target_bytesize;
 	}
 	
-	if(strlen(binary_string) < target_bitsize) {
+	if(binary_length < target_bitsize) {
 		/* Now add padding to binary string */
 		if (alpha_pad == 1) {
 			concat(binary_string, "11111");
@@ -1662,7 +1663,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 {
 	int errno, cc_mode, cc_width, ecc_level;
 	int j, last_ai, ai_latch, i, k, separator_row;
-	char reduced[3000], binary_string[10 * strlen(source)], ai_string[4];
+	char reduced[3000], binary_string[10 * ustrlen(source)], ai_string[4];
 	struct zint_symbol *linear;
 	int top_shift, bottom_shift;
 	
@@ -1674,7 +1675,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 		return ERROR_INVALID_OPTION;
 	}
 	
-	if(strlen(source) > 2990) {
+	if(ustrlen(source) > 2990) {
 		strcpy(symbol->errtxt, "error: 2D component input data too long");
 		return ERROR_TOO_LONG;
 	}
@@ -1684,7 +1685,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 		return ERROR_INVALID_DATA;
 	}
 	
-	for(i = 0; i < strlen(source) - 1; i++) {
+	for(i = 0; i < ustrlen(source) - 1; i++) {
 		if((source[i] == '[') && (source[i + 1] == '[')) {
 			/* Can't have nested brackets - Quit */
 			strcpy(symbol->errtxt, "Nested AI detected (two or more open brackets)");
@@ -1692,7 +1693,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 		}
 	}
 	
-	for(i = 0; i < strlen(source) - 1; i++) {
+	for(i = 0; i < ustrlen(source) - 1; i++) {
 		if((source[i] == ']') && (source[i + 1] == ']')) {
 			/* Can't have nested brackets - Quit */
 			strcpy(symbol->errtxt, "Nested AI detected (two or more close brackets)");
@@ -1706,7 +1707,7 @@ int composite(struct zint_symbol *symbol, unsigned char source[])
 	j = 0;
 	last_ai = 0;
 	ai_latch = 1;
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if((source[i] != '[') && (source[i] != ']')) {
 			reduced[j] = source[i];
 			j++;
diff --git a/backend/dmatrix.c b/backend/dmatrix.c
index 3fff9977..a7440bae 100644
--- a/backend/dmatrix.c
+++ b/backend/dmatrix.c
@@ -79,7 +79,7 @@ int dmatrix(struct zint_symbol *symbol, unsigned char source[])
 		barcode[barcodelen] = 0;	// null terminate anyway
 		fclose(f); 
 } else */
-		barcodelen = strlen(source);
+		barcodelen = ustrlen(source);
 		if(barcodelen > 780) {
 			strcpy(symbol->errtxt, "error: input too long");
 			return ERROR_TOO_LONG;
diff --git a/backend/imail.c b/backend/imail.c
index 3047f1b3..fe4cc6e8 100644
--- a/backend/imail.c
+++ b/backend/imail.c
@@ -22,6 +22,18 @@
 /*  The function "USPS_MSB_Math_CRC11GenerateFrameCheckSequence"
     is Copyright (C) 2006 United States Postal Service */
 
+static short int BCD[40] = {
+	0, 0, 0, 0,
+ 1, 0, 0, 0,
+ 0, 1, 0, 0,
+ 1, 1, 0, 0,
+ 0, 0, 1, 0,
+ 1, 0, 1, 0,
+ 0, 1, 1, 0,
+ 1, 1, 1, 0,
+ 0, 0, 0, 1,
+ 1, 0, 0, 1 };
+
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -300,7 +312,7 @@ int imail(struct zint_symbol *symbol, unsigned char source[])
 	
 	errno = 0;
 
-	if(strlen(source) > 32) {
+	if(ustrlen(source) > 32) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -325,7 +337,7 @@ int imail(struct zint_symbol *symbol, unsigned char source[])
 	
 	read = 0;
 	j = 0;
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if(source[i] == '-') {
 			tracker[read] = '\0';
 			j = 1;
diff --git a/backend/large.c b/backend/large.c
index ca16e10a..606f598d 100644
--- a/backend/large.c
+++ b/backend/large.c
@@ -19,6 +19,7 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
+#include "common.h"
 #include <stdio.h>
 #include <string.h>
 
diff --git a/backend/large.h b/backend/large.h
index b7b8846e..742db823 100644
--- a/backend/large.h
+++ b/backend/large.h
@@ -19,18 +19,6 @@
     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-static short int BCD[40] = {
-	0, 0, 0, 0,
-	1, 0, 0, 0,
-	0, 1, 0, 0,
-	1, 1, 0, 0,
-	0, 0, 1, 0,
-	1, 0, 1, 0,
-	0, 1, 1, 0,
-	1, 1, 1, 0,
-	0, 0, 0, 1,
-	1, 0, 0, 1 };
-
 void binary_load(short int reg[], char data[]);
 void binary_add(short int accumulator[], short int input_buffer[]);
 void binary_subtract(short int accumulator[], short int input_buffer[]);
diff --git a/backend/maxicode.c b/backend/maxicode.c
index 7b446588..03f76458 100644
--- a/backend/maxicode.c
+++ b/backend/maxicode.c
@@ -25,6 +25,7 @@
 #include "maxicode.h"
 #include "reedsol.h"
 #include <string.h>
+#include <stdlib.h>
 
 int maxi_codeword[144];
 
@@ -97,7 +98,7 @@ void maxi_do_secondary_chk_even(int ecclen )
 		maxi_codeword[ datalen + (2 *j) + 20] = results[j];
 }
 
-int maxi_bump(int set[], int character[], int bump_posn)
+void maxi_bump(int set[], int character[], int bump_posn)
 {
 	/* Moves everything up so that a shift or latch can be inserted */
 	int i;
@@ -118,7 +119,7 @@ int maxi_text_process(int mode, unsigned char source[])
 	
 	int set[144], character[144], i, j, done, count, length, current_set;
 	
-	length = strlen(source);
+	length = ustrlen(source);
 	
 	if(length > 138) {
 		return ERROR_TOO_LONG;
@@ -297,7 +298,7 @@ int maxi_text_process(int mode, unsigned char source[])
 		}
 	}
 	
-	for(i = strlen(source); i < 144; i++) {
+	for(i = ustrlen(source); i < 144; i++) {
 		/* Add the padding */
 		if(set[length - 1] == 2) {
 			set[i] = 2;
diff --git a/backend/medical.c b/backend/medical.c
index f4455d58..5c8046ca 100644
--- a/backend/medical.c
+++ b/backend/medical.c
@@ -55,7 +55,7 @@ int pharma_one(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 6) {
+	if(ustrlen(source) > 6) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -158,7 +158,7 @@ int pharma_two(struct zint_symbol *symbol, unsigned char source[])
 	int error_number = 0;
 	strcpy(height_pattern, "");
 
-	if(strlen(source) > 8) {
+	if(ustrlen(source) > 8) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -201,7 +201,7 @@ int codabar(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 60) { /* No stack smashing please */
+	if(ustrlen(source) > 60) { /* No stack smashing please */
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -220,14 +220,14 @@ int codabar(struct zint_symbol *symbol, unsigned char source[])
 		return 6;
 	}
 
-	if(((source[strlen(source) - 1] != 'A') && (source[strlen(source) - 1] != 'B')) &&
-		    ((source[strlen(source) - 1] != 'C') && (source[strlen(source) - 1] != 'D')))
+	if(((source[ustrlen(source) - 1] != 'A') && (source[ustrlen(source) - 1] != 'B')) &&
+		    ((source[ustrlen(source) - 1] != 'C') && (source[ustrlen(source) - 1] != 'D')))
 	{
 		strcpy(symbol->errtxt, "error: invalid characters in data");
 		return 6;
 	}
 
-	for(i = 0; i <= strlen(source); i++)
+	for(i = 0; i <= ustrlen(source); i++)
 	{
 		lookup(CASET, CodaTable, source[i], dest);
 	}
@@ -246,7 +246,7 @@ int code32(struct zint_symbol *symbol, unsigned char source[])
 	char tabella[34];
 	
 	/* Validate the input */
-	if(strlen(source) > 8) {
+	if(ustrlen(source) > 8) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -258,7 +258,7 @@ int code32(struct zint_symbol *symbol, unsigned char source[])
 	
 	/* Add leading zeros as required */
 	strcpy(localstr, "");
-	zeroes = 8 - strlen(source);
+	zeroes = 8 - ustrlen(source);
 	for(i = 0; i < zeroes; i++) {
 		concat(localstr, "0");
 	}
diff --git a/backend/pdf417.c b/backend/pdf417.c
index 6d25239d..69dab2e9 100644
--- a/backend/pdf417.c
+++ b/backend/pdf417.c
@@ -292,8 +292,7 @@ void textprocess(int *chainemc, int *mclength, char chaine[], int start, int len
 void byteprocess(int *chainemc, int *mclength, unsigned char chaine[], int start, int length, int block)
 {
 	
-	int i, j, k, l, loop, longueur;
-	double multiple, total;
+	int i, j, k, l, longueur;
 	short int accum[112], x_reg[112], y_reg[112];
 	
 	if(length == 1) {
@@ -476,13 +475,13 @@ int pdf417(struct zint_symbol *symbol, unsigned char chaine[])
 	/* 463 */
 	do {
 		liste[1][indexliste] = mode;
-		while ((liste[1][indexliste] == mode) && (indexchaine < strlen(chaine))) {
+		while ((liste[1][indexliste] == mode) && (indexchaine < ustrlen(chaine))) {
 			liste[0][indexliste]++;
 			indexchaine++;
 			mode = quelmode(chaine[indexchaine]);
 		}
 		indexliste++;
-	} while (indexchaine < strlen(chaine));
+	} while (indexchaine < ustrlen(chaine));
 	
 	/* 474 */
 	pdfsmooth(&indexliste);
@@ -761,13 +760,13 @@ int micro_pdf417(struct zint_symbol *symbol, unsigned char chaine[])
 	/* 463 */
 	do {
 		liste[1][indexliste] = mode;
-		while ((liste[1][indexliste] == mode) && (indexchaine < strlen(chaine))) {
+		while ((liste[1][indexliste] == mode) && (indexchaine < ustrlen(chaine))) {
 			liste[0][indexliste]++;
 			indexchaine++;
 			mode = quelmode(chaine[indexchaine]);
 		}
 		indexliste++;
-	} while (indexchaine < strlen(chaine));
+	} while (indexchaine < ustrlen(chaine));
 	
 	/* 474 */
 	pdfsmooth(&indexliste);
diff --git a/backend/pdf417.h b/backend/pdf417.h
index 8d2b4df9..da62c2b5 100644
--- a/backend/pdf417.h
+++ b/backend/pdf417.h
@@ -451,3 +451,4 @@ static char *RAPC[53] = {"", "112231", "121231", "122131", "131131", "131221", "
 	"112213", "112222", "112312", "112321", "111421", "111331", "111322", "111232", "111223",
 	"111133", "111124", "111214", "112114", "121114", "121123", "121132", "112132", "112141" };
 
+void byteprocess(int *chainemc, int *mclength, unsigned char chaine[], int start, int length, int block);
\ No newline at end of file
diff --git a/backend/plessey.c b/backend/plessey.c
index 3fdc0cde..a352c22a 100644
--- a/backend/plessey.c
+++ b/backend/plessey.c
@@ -46,7 +46,7 @@ int plessey(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 65) {
+	if(ustrlen(source) > 65) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -55,13 +55,13 @@ int plessey(struct zint_symbol *symbol, unsigned char source[])
 		strcpy(symbol->errtxt, "error: invalid characters in data");
 		return error_number;
 	}
-	checkptr = calloc (1, strlen(source) * 4 + 8);
+	checkptr = calloc (1, ustrlen(source) * 4 + 8);
 
 	/* Start character */
 	concat(dest, "31311331");
 
 	/* Data area */
-	for(i = 0; i <= strlen(source); i++)
+	for(i = 0; i <= ustrlen(source); i++)
 	{
 		check = posn(SSET, source[i]);
 		lookup(SSET, PlessTable, source[i], dest);
@@ -74,7 +74,7 @@ int plessey(struct zint_symbol *symbol, unsigned char source[])
 	/* CRC check digit code adapted from code by Leonid A. Broukhis
 	   used in GNU Barcode */
 
-	for (i=0; i < 4*strlen(source); i++) {
+	for (i=0; i < 4*ustrlen(source); i++) {
 		int j;
 		if (checkptr[i])
 			for (j = 0; j < 9; j++)
@@ -82,7 +82,7 @@ int plessey(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 	for (i = 0; i < 8; i++) {
-		switch(checkptr[strlen(source) * 4 + i])
+		switch(checkptr[ustrlen(source) * 4 + i])
 		{
 			case 0: concat(dest, "13"); break;
 			case 1: concat(dest, "31"); break;
@@ -107,7 +107,7 @@ int msi_plessey(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 55) {
+	if(ustrlen(source) > 55) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -120,7 +120,7 @@ int msi_plessey(struct zint_symbol *symbol, unsigned char source[])
 	/* start character */
 	concat (dest, "21");
 
-	for(i = 0; i <= strlen(source); i++)
+	for(i = 0; i <= ustrlen(source); i++)
 	{
 		lookup(NESET, MSITable, source[i], dest);
 	}
@@ -145,7 +145,7 @@ int msi_plessey_mod10(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 55) { 
+	if(ustrlen(source) > 55) { 
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -159,16 +159,16 @@ int msi_plessey_mod10(struct zint_symbol *symbol, unsigned char source[])
 	concat (dest, "21");
 
 	/* draw data section */
-	for(i = 0; i < strlen(source); i++)
+	for(i = 0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, MSITable, source[i], dest);
 	}
 
 	/* caluculate check digit */
 	wright = 0;
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -176,7 +176,7 @@ int msi_plessey_mod10(struct zint_symbol *symbol, unsigned char source[])
 	}
 	else
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -196,16 +196,16 @@ int msi_plessey_mod10(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
 	}
 	else
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
@@ -223,7 +223,7 @@ int msi_plessey_mod10(struct zint_symbol *symbol, unsigned char source[])
 	/* Stop character */
 	concat (dest, "121");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(pump);
 	source[h + 1] = '\0';
 	expand(symbol, dest);
@@ -243,7 +243,7 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 55) { /* No Entry Stack Smashers! */
+	if(ustrlen(source) > 55) { /* No Entry Stack Smashers! */
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -257,16 +257,16 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	concat (dest, "21");
 
 	/* draw data section */
-	for(i = 0; i < strlen(source); i++)
+	for(i = 0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, MSITable, source[i], dest);
 	}
 
 	/* calculate first check digit */
 	wright = 0;
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -274,7 +274,7 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	}
 	else
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -294,16 +294,16 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
 	}
 	else
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
@@ -317,9 +317,9 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 
 	/* calculate second check digit */
 	wright = 0;
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -327,7 +327,7 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	}
 	else
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -349,16 +349,16 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
 	}
 	else
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
@@ -377,7 +377,7 @@ int msi_plessey_mod1010(struct zint_symbol *symbol, unsigned char source[])
 	/* Stop character */
 	concat (dest, "121");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(pump);
 	source[h + 1] = itoc(chwech);
 	source[h + 2] = '\0';
@@ -400,7 +400,7 @@ int msi_plessey_mod11(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 55) {
+	if(ustrlen(source) > 55) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -414,7 +414,7 @@ int msi_plessey_mod11(struct zint_symbol *symbol, unsigned char source[])
 	concat (dest, "21");
 	
 	/* draw data section */
-	for(i = 0; i < strlen(source); i++)
+	for(i = 0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, MSITable, source[i], dest);
 	}
@@ -422,7 +422,7 @@ int msi_plessey_mod11(struct zint_symbol *symbol, unsigned char source[])
 	/* calculate check digit */
 	x = 0;
 	weight = 2;
-	for(i = (strlen(source) - 1); i >= 0; i--) {
+	for(i = (ustrlen(source) - 1); i >= 0; i--) {
 		x += weight * ctoi(source[i]);
 		weight++;
 		if(weight > 7) {
@@ -438,7 +438,7 @@ int msi_plessey_mod11(struct zint_symbol *symbol, unsigned char source[])
 		lookup(NESET, MSITable, itoc(check), dest);
 	}
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	if(check == 10) {
 		source[h] = '1';
 		source[h + 1] = '0';
@@ -470,7 +470,7 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 
-	if(strlen(source) > 55) {
+	if(ustrlen(source) > 55) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -484,16 +484,16 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	concat (dest, "21");
 	
 	/* draw data section */
-	for(i = 0; i < strlen(source); i++)
+	for(i = 0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, MSITable, source[i], dest);
 	}
 
 	/* calculate first (mod 11) digit */
-	wright = strlen(source);
+	wright = ustrlen(source);
 	x = 0;
 	weight = 2;
-	for(i = (strlen(source) - 1); i >= 0; i--) {
+	for(i = (ustrlen(source) - 1); i >= 0; i--) {
 		x += weight * ctoi(source[i]);
 		weight++;
 		if(weight > 7) {
@@ -516,9 +516,9 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	
 	/* caluculate second (mod 10) check digit */
 	wright = 0;
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -526,7 +526,7 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	}
 	else
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			un[wright] = source[i];
 			wright ++;
@@ -546,16 +546,16 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	}
 
 
-	if((strlen(source)%2) == 0)
+	if((ustrlen(source)%2) == 0)
 	{
-		for(i = 0; i < strlen(source); i+=2)
+		for(i = 0; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
 	}
 	else
 	{
-		for(i = 1; i < strlen(source); i+=2)
+		for(i = 1; i < ustrlen(source); i+=2)
 		{
 			pedwar += ctoi(source[i]);
 		}
@@ -573,7 +573,7 @@ int msi_plessey_mod1110(struct zint_symbol *symbol, unsigned char source[])
 	/* stop character */
 	concat (dest, "121");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(pump);
 	source[h + 1] = '\0';
 
diff --git a/backend/png.c b/backend/png.c
index e72f39b1..342fe643 100644
--- a/backend/png.c
+++ b/backend/png.c
@@ -61,10 +61,9 @@ int png_to_file(struct zint_symbol *symbol, int image_height, int image_width, c
 	png_structp  png_ptr;
 	png_infop  info_ptr;
 	graphic = &wpng_info;
-	long j;
 	unsigned long rowbytes;
 	unsigned char *image_data;
-	int i, k, offset, row, column, errno;
+	int i, row, column, errno;
 	int fgred, fggrn, fgblu, bgred, bggrn, bgblu;
 	
 	switch(rotate_angle) {
@@ -356,7 +355,7 @@ void draw_string(char *pixbuf, unsigned char input_string[], int xposn, int ypos
 	/* Plot a string into the pixel buffer */
 	int i, string_length, string_left_hand;
 	
-	string_length = strlen(input_string);
+	string_length = ustrlen(input_string);
 	string_left_hand = xposn - ((7 * string_length) / 2);
 	
 	for(i = 0; i < string_length; i++) {
diff --git a/backend/postal.c b/backend/postal.c
index e712a233..d93821df 100644
--- a/backend/postal.c
+++ b/backend/postal.c
@@ -56,7 +56,7 @@ int postnet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	
 	error_number = 0;
 
-	if(strlen(source) > 90) {
+	if(ustrlen(source) > 90) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -70,7 +70,7 @@ int postnet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* start character */
 	concat (dest, "L");
 
-	for (i=0; i < strlen(source); i++)
+	for (i=0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, PNTable, source[i], dest);
 		sum += ctoi(source[i]);
@@ -82,7 +82,7 @@ int postnet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* stop character */
 	concat (dest, "L");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(check_digit);
 	source[h + 1] = '\0';
 	strcpy(symbol->text, "");
@@ -132,7 +132,7 @@ int planet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	
 	error_number = 0;
 	
-	if(strlen(source) > 90) {
+	if(ustrlen(source) > 90) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -146,7 +146,7 @@ int planet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* start character */
 	concat (dest, "L");
 
-	for (i=0; i < strlen(source); i++)
+	for (i=0; i < ustrlen(source); i++)
 	{
 		lookup(NESET, PLTable, source[i], dest);
 		sum += ctoi(source[i]);
@@ -158,7 +158,7 @@ int planet(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* stop character */
 	concat (dest, "L");
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = itoc(check_digit);
 	source[h + 1] = '\0';
 	strcpy(symbol->text, "");
@@ -211,7 +211,7 @@ int fim(struct zint_symbol *symbol, unsigned char source[])
 	strcpy(dest, "");
 	
 	to_upper(source);
-	if(strlen(source) > 1) {
+	if(ustrlen(source) > 1) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -274,7 +274,7 @@ int royal_plot(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	
 	to_upper(source);
-	if(strlen(source) > 120) {
+	if(ustrlen(source) > 120) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -306,7 +306,7 @@ int royal_plot(struct zint_symbol *symbol, unsigned char source[])
 	symbol->rows = 3;
 	symbol->width = writer - 1;
 	
-	h = strlen(source);
+	h = ustrlen(source);
 	source[h] = check;
 	source[h + 1] = '\0';
 	strcpy(symbol->text, "");
@@ -328,7 +328,7 @@ int kix_code(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	
 	to_upper(source);
-	if(strlen(source) != 11) {
+	if(ustrlen(source) != 11) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -337,7 +337,7 @@ int kix_code(struct zint_symbol *symbol, unsigned char source[])
 		strcpy(symbol->errtxt, "error: invalid characters in data");
 		return error_number;
 	}
-	for (i = 0; i < strlen(source); i++) {
+	for (i = 0; i < ustrlen(source); i++) {
 		lookup(KRSET, RoyalTable, source[i], height_pattern);
 	}
 	
@@ -377,7 +377,7 @@ int daft_code(struct zint_symbol *symbol, unsigned char source[])
 	int writer, i;
 	strcpy(height_pattern, "");
 	
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 	strcpy(local_source, source);
 	if(input_length > 50) {
 		strcpy(symbol->errtxt, "Input too long");
@@ -427,7 +427,7 @@ int flattermarken(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	
-	if(strlen(source) > 90) {
+	if(ustrlen(source) > 90) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -437,7 +437,7 @@ int flattermarken(struct zint_symbol *symbol, unsigned char source[])
 		return error_number;
 	}
 	
-	for(loop = 0; loop < strlen(source); loop++) {
+	for(loop = 0; loop < ustrlen(source); loop++) {
 		lookup(NESET, FlatTable, source[loop], dest);
 	}
 	
diff --git a/backend/qr.c b/backend/qr.c
index dc8cd0df..6ee35055 100644
--- a/backend/qr.c
+++ b/backend/qr.c
@@ -27,7 +27,6 @@
 #include <qrencode.h>
 
 static int kanji = 0;
-static QRecLevel level = QR_ECLEVEL_L;
 
 QRcode *encode(int security, int size, const unsigned char *intext)
 {
diff --git a/backend/rss.c b/backend/rss.c
index 6b2a7147..0b662677 100644
--- a/backend/rss.c
+++ b/backend/rss.c
@@ -94,7 +94,6 @@ void getRSSwidths(int val, int n, int elements, int maxWidth, int noNarrow)
 {
 	int bar;
 	int elmWidth;
-	int i;
 	int mxwElement;
 	int subVal, lessVal;
 	int narrowMask = 0;
@@ -141,7 +140,7 @@ void getRSSwidths(int val, int n, int elements, int maxWidth, int noNarrow)
 
 int rss14(struct zint_symbol *symbol, unsigned char source[])
 { /* GS1 DataBar-14 */
-	int error_number = 0, i, j, read, mask;
+	int error_number = 0, i, j, mask;
 	short int accum[112], left_reg[112], right_reg[112], x_reg[112], y_reg[112];
 	int data_character[4], data_group[4], v_odd[4], v_even[4];
 	int data_widths[8][4], checksum, c_left, c_right, total_widths[46], writer;
@@ -150,7 +149,7 @@ int rss14(struct zint_symbol *symbol, unsigned char source[])
 	
 	separator_row = 0;
 
-	if(strlen(source) > 13) {
+	if(ustrlen(source) > 13) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -427,8 +426,8 @@ int rss14(struct zint_symbol *symbol, unsigned char source[])
 		for(i = 0; i < 14; i++) {
 			hrt[i] = '0';
 		}
-		for(i = 0; i < strlen(source); i++) {
-			hrt[12 - i] = source[strlen(source) - i - 1];
+		for(i = 0; i < ustrlen(source); i++) {
+			hrt[12 - i] = source[ustrlen(source) - i - 1];
 		}
 		hrt[14] = '\0';
 	
@@ -647,7 +646,7 @@ int rsslimited(struct zint_symbol *symbol, unsigned char source[])
 
 	separator_row = 0;
 	
-	if(strlen(source) > 13) {
+	if(ustrlen(source) > 13) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -876,8 +875,8 @@ int rsslimited(struct zint_symbol *symbol, unsigned char source[])
 	for(i = 0; i < 14; i++) {
 		hrt[i] = '0';
 	}
-	for(i = 0; i < strlen(source); i++) {
-		hrt[12 - i] = source[strlen(source) - i - 1];
+	for(i = 0; i < ustrlen(source); i++) {
+		hrt[12 - i] = source[ustrlen(source) - i - 1];
 	}
 	
 	for (i = 0; i < 13; i++)
@@ -1020,7 +1019,7 @@ int general_rules(char field[], char type[])
 int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char binary_string[])
 { /* Handles all data encodation from section 7.2.5 of ISO/IEC 24724 */
 	int encoding_method, i, mask, j, read_posn, latch;
-	char general_field[strlen(source)], general_field_type[strlen(source)];
+	char general_field[ustrlen(source)], general_field_type[ustrlen(source)];
 	int remainder, d1, d2, value;
 	char padstring[14];
 	
@@ -1028,7 +1027,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 	/* Decide whether a compressed data field is required and if so what
 	method to use - method 2 = no compressed data field */
 	
-	if((strlen(source) >= 16) && ((source[0] == '0') && (source[1] == '1'))) {
+	if((ustrlen(source) >= 16) && ((source[0] == '0') && (source[1] == '1'))) {
 		/* (01) and other AIs */
 		encoding_method = 1;
 	} else {
@@ -1036,10 +1035,10 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 		encoding_method = 2;
 	}
 	
-	if(((strlen(source) >= 20) && (encoding_method == 1)) && ((source[2] == '9') && (source[16] == '3'))) {
+	if(((ustrlen(source) >= 20) && (encoding_method == 1)) && ((source[2] == '9') && (source[16] == '3'))) {
 		/* Possibly encoding method > 2 */
 		
-		if((strlen(source) >= 26) && (source[17] == '1')) {
+		if((ustrlen(source) >= 26) && (source[17] == '1')) {
 			/* Methods 3, 7, 9, 11 and 13 */
 			
 			if(source[18] == '0') {
@@ -1057,14 +1056,14 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 
 					encoding_method = 7;
 					
-					if((source[19] == '3') && (strlen(source) == 26)) {
+					if((source[19] == '3') && (ustrlen(source) == 26)) {
 						/* (01) and (3103) */
 						weight = atof(weight_str) / 1000.0;
 						
 						if(weight <= 32.767) { encoding_method = 3; }
 					}
 					
-					if(strlen(source) == 34){
+					if(ustrlen(source) == 34){
 						if((source[26] == '1') && (source[27] == '1')) {
 							/* (01), (310x) and (11) - metric weight and production date */
 							encoding_method = 7;
@@ -1089,7 +1088,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 			}
 		}
 		
-		if((strlen(source) >= 26) && (source[17] == '2')) {
+		if((ustrlen(source) >= 26) && (source[17] == '2')) {
 			/* Methods 4, 8, 10, 12 and 14 */
 			
 			if(source[18] == '0') {
@@ -1106,7 +1105,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 
 					encoding_method = 8;
 					
-					if(((source[19] == '2') || (source[19] == '3')) && (strlen(source) == 26)) {
+					if(((source[19] == '2') || (source[19] == '3')) && (ustrlen(source) == 26)) {
 						/* (01) and (3202)/(3203) */
 						
 						if(source[19] == '3') {
@@ -1123,7 +1122,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 						
 					}
 					
-					if(strlen(source) == 34){
+					if(ustrlen(source) == 34){
 						if((source[26] == '1') && (source[27] == '1')) {
 							/* (01), (320x) and (11) - English weight and production date */
 							encoding_method = 8;
@@ -1165,18 +1164,18 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 	switch(encoding_method) { /* Encoding method - Table 10 */
 		case 1: concat(binary_string, "1XX"); read_posn = 16; break;
 		case 2: concat(binary_string, "00XX"); read_posn = 0; break;
-		case 3: concat(binary_string, "0100"); read_posn = strlen(source); break;
-		case 4: concat(binary_string, "0101"); read_posn = strlen(source); break;
+		case 3: concat(binary_string, "0100"); read_posn = ustrlen(source); break;
+		case 4: concat(binary_string, "0101"); read_posn = ustrlen(source); break;
 		case 5: concat(binary_string, "01100XX"); read_posn = 20; break;
 		case 6: concat(binary_string, "01101XX"); read_posn = 23; break;
-		case 7: concat(binary_string, "0111000"); read_posn = strlen(source); break;
-		case 8: concat(binary_string, "0111001"); read_posn = strlen(source); break;
-		case 9: concat(binary_string, "0111010"); read_posn = strlen(source); break;
-		case 10: concat(binary_string, "0111011"); read_posn = strlen(source); break;
-		case 11: concat(binary_string, "0111100"); read_posn = strlen(source); break;
-		case 12: concat(binary_string, "0111101"); read_posn = strlen(source); break;
-		case 13: concat(binary_string, "0111110"); read_posn = strlen(source); break;
-		case 14: concat(binary_string, "0111111"); read_posn = strlen(source); break;
+		case 7: concat(binary_string, "0111000"); read_posn = ustrlen(source); break;
+		case 8: concat(binary_string, "0111001"); read_posn = ustrlen(source); break;
+		case 9: concat(binary_string, "0111010"); read_posn = ustrlen(source); break;
+		case 10: concat(binary_string, "0111011"); read_posn = ustrlen(source); break;
+		case 11: concat(binary_string, "0111100"); read_posn = ustrlen(source); break;
+		case 12: concat(binary_string, "0111101"); read_posn = ustrlen(source); break;
+		case 13: concat(binary_string, "0111110"); read_posn = ustrlen(source); break;
+		case 14: concat(binary_string, "0111111"); read_posn = ustrlen(source); break;
 	}
 	
 	/* Variable length symbol bit field is just given a place holder (XX)
@@ -1373,7 +1372,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 			mask = mask >> 1;
 		}
 		
-		if(strlen(source) == 34) {
+		if(ustrlen(source) == 34) {
 			/* Date information is included */
 			date_str[0] = source[28];
 			date_str[1] = source[29];
@@ -1490,7 +1489,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 	rest of the data (if any) goes into a general-purpose data compaction field */
 	
 	j = 0;
-	for(i = read_posn; i < strlen(source); i++) {
+	for(i = read_posn; i < ustrlen(source); i++) {
 		general_field[j] = source[i];
 		j++;
 	}
@@ -1828,7 +1827,7 @@ int rss_binary_string(struct zint_symbol *symbol, unsigned char source[], char b
 int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 { /* GS1 DataBar Expanded */
 	int i, j, k, l, data_chars, vs[21], group[21], v_odd[21], v_even[21];
-	char binary_string[7 * strlen(source)], substring[21][14], latch;
+	char binary_string[7 * ustrlen(source)], substring[21][14], latch;
 	int char_widths[21][8], checksum, check_widths[8], c_group;
 	int check_char, c_odd, c_even, elements[235], pattern_width, reader, writer;
 	int row, elements_in_sub, special_case_row, left_to_right;
@@ -1843,7 +1842,7 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 		return ERROR_INVALID_DATA;
 	}
 	
-	for(i = 0; i < strlen(source) - 1; i++) {
+	for(i = 0; i < ustrlen(source) - 1; i++) {
 		if((source[i] == '[') && (source[i + 1] == '[')) {
 			/* Can't have nested brackets - Quit */
 			strcpy(symbol->errtxt, "Nested AI detected (two or more open brackets)");
@@ -1851,7 +1850,7 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 		}
 	}
 	
-	for(i = 0; i < strlen(source) - 1; i++) {
+	for(i = 0; i < ustrlen(source) - 1; i++) {
 		if((source[i] == ']') && (source[i + 1] == ']')) {
 			/* Can't have nested brackets - Quit */
 			strcpy(symbol->errtxt, "Nested AI detected (two or more close brackets)");
@@ -1878,7 +1877,7 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 	j = 0;
 	last_ai = 0;
 	ai_latch = 1;
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if((source[i] != '[') && (source[i] != ']')) {
 			reduced[j] = source[i];
 			j++;
@@ -1963,6 +1962,9 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 		char_widths[i][7] = widths[3];
 	}
 	
+	/* 7.2.6 Check character */
+	/* The checksum value is equal to the mod 211 residue of the weighted sum of the widths of the
+	   elements in the data characters. */
 	checksum = 0;
 	for(i = 0; i < data_chars; i++) {
 		row = weight_rows[(((data_chars - 3) / 2) * 21) + i];
@@ -1972,7 +1974,6 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 		}
 	}
 	
-	checksum;
 	check_char = (211 * ((data_chars + 1) - 4)) + (checksum % 211);
 	
 	if(check_char <= 347) { c_group = 1; }
@@ -2072,7 +2073,7 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[])
 		}
 		
 		/* Add human readable text */
-		for(i = 0; i <= strlen(source); i++) {
+		for(i = 0; i <= ustrlen(source); i++) {
 			if((source[i] != '[') && (source[i] != ']')) {
 				symbol->text[i] = source[i];
 			} else {
diff --git a/backend/telepen.c b/backend/telepen.c
index 348efd2b..0383520d 100644
--- a/backend/telepen.c
+++ b/backend/telepen.c
@@ -61,12 +61,12 @@ int telepen(struct zint_symbol *symbol, unsigned char source[])
 
 	count = 0;
 
-	if(strlen(source) > 30) {
+	if(ustrlen(source) > 30) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
 
-	for(i = 0; i < strlen(source); i++) {
+	for(i = 0; i < ustrlen(source); i++) {
 		if(source[i] > 127) {
 			/* Cannot encode extended ASCII */
 			strcpy(symbol->errtxt, "error: invalid characters in input data");
@@ -77,7 +77,7 @@ int telepen(struct zint_symbol *symbol, unsigned char source[])
 	/* Start character */
 	concat(dest, TeleTable['_']);
 
-	for (i=0; i < strlen(source); i++)
+	for (i=0; i < ustrlen(source); i++)
 	{
 		ascii_value = source[i];
 		concat(dest, TeleTable[ascii_value]);
@@ -105,7 +105,7 @@ int telepen_num(struct zint_symbol *symbol, unsigned char source[])
 	error_number = 0;
 	strcpy(dest, "");
 	strcpy(local_source, source);
-	input_length = strlen(source);
+	input_length = ustrlen(source);
 
 	count = 0;
 
diff --git a/backend/upcean.c b/backend/upcean.c
index 91448c6f..bac8254e 100644
--- a/backend/upcean.c
+++ b/backend/upcean.c
@@ -49,7 +49,7 @@ char upc_check(unsigned char source[])
 
 	count = 0;
 
-	for (i = 0; i < strlen(source); i++)
+	for (i = 0; i < ustrlen(source); i++)
 	{
 		count += ctoi(source[i]);
 
@@ -68,12 +68,12 @@ void upca_draw(unsigned char source[], char dest[])
 { /* UPC A is usually used for 12 digit numbers, but this function takes a source of any length */
 	unsigned int i, half_way;
 
-	half_way = strlen(source) / 2;
+	half_way = ustrlen(source) / 2;
 
 	/* start character */
 	concat (dest, "111");
 
-	for(i = 0; i <= strlen(source); i++)
+	for(i = 0; i <= ustrlen(source); i++)
 	{
 		if (i == half_way)
 		{
@@ -93,7 +93,7 @@ void upca(struct zint_symbol *symbol, unsigned char source[], char dest[])
 { /* Make a UPC A barcode when we haven't been given the check digit */
 	int length;
 
-	length = strlen(source);
+	length = ustrlen(source);
 	source[length] = upc_check(source);
 	source[length + 1] = '\0';
 	upca_draw(source, dest);
@@ -107,7 +107,7 @@ void upce(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	char hrt[8];
 
 	/* Two number systems can be used - system 0 and system 1 */
-	if(strlen(source) == 7) {
+	if(ustrlen(source) == 7) {
 		switch(source[0]) {
 			case '0': num_system = 0; break;
 			case '1': num_system = 1; break;
@@ -195,7 +195,7 @@ void upce(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* start character */
 	concat (dest, "111");
 
-	for(i = 0; i <= strlen(source); i++) {
+	for(i = 0; i <= ustrlen(source); i++) {
 		switch(parity[i]) {
 			case 'A': lookup(NESET, EANsetA, source[i], dest); break;
 			case 'B': lookup(NESET, EANsetB, source[i], dest); break;
@@ -226,7 +226,7 @@ void add_on(unsigned char source[], char dest[], int mode)
 	concat (dest, "112");
 
 	/* Determine EAN2 or EAN5 add-on */
-	if(strlen(source) == 2)
+	if(ustrlen(source) == 2)
 	{
 		code_type = EAN2;
 	}
@@ -261,7 +261,7 @@ void add_on(unsigned char source[], char dest[], int mode)
 		strcpy(parity, EAN5Parity[parity_bit]);
 	}
 
-	for(i = 0; i < strlen(source); i++)
+	for(i = 0; i < ustrlen(source); i++)
 	{
 		switch(parity[i]) {
 			case 'A': lookup(NESET, EANsetA, source[i], dest); break;
@@ -269,7 +269,7 @@ void add_on(unsigned char source[], char dest[], int mode)
 		}
 
 		/* Glyph separator */
-		if(i != (strlen(source) - 1))
+		if(i != (ustrlen(source) - 1))
 		{
 			concat (dest, "11");
 		}
@@ -286,7 +286,7 @@ char ean_check(unsigned char source[])
 
 	count = 0;
 
-	h = strlen(source);
+	h = ustrlen(source);
 	for (i = h - 1; i >= 0; i--)
 	{
 		count += ctoi(source[i]);
@@ -309,7 +309,7 @@ void ean13(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	strcpy(parity, "");
 	
 	/* Add the appropriate check digit */
-	length = strlen(source);
+	length = ustrlen(source);
 	source[length] = ean_check(source);
 	source[length + 1] = '\0';
 
@@ -322,7 +322,7 @@ void ean13(struct zint_symbol *symbol, unsigned char source[], char dest[])
 	/* start character */
 	concat (dest, "111");
 
-	for(i = 1; i <= strlen(source); i++)
+	for(i = 1; i <= ustrlen(source); i++)
 	{
 		if (i == half_way)
 		{
@@ -352,7 +352,7 @@ void ean8(struct zint_symbol *symbol, unsigned char source[], char dest[])
   /* EAN-8 is basically the same as UPC-A but with fewer digits */
 	int length;
 
-	length = strlen(source);
+	length = ustrlen(source);
 	source[length] = upc_check(source);
 	source[length + 1] = '\0';
 	upca_draw(source, dest);
@@ -366,7 +366,7 @@ char isbn13_check(unsigned char source[]) /* For ISBN(13) only */
 	sum = 0;
 	weight = 1;
 
-	for(i = 0; i < (strlen(source) - 1); i++)
+	for(i = 0; i < (ustrlen(source) - 1); i++)
 	{
 		sum += ctoi(source[i]) * weight;
 		if(weight == 1) weight = 3; else weight = 1;
@@ -383,7 +383,7 @@ char isbn_check(unsigned char source[]) /* For ISBN(10) and SBN only */
 
 	sum = 0;
 	weight = 1;
-	for(i = 0; i < (strlen(source) - 1); i++)
+	for(i = 0; i < (ustrlen(source) - 1); i++)
 	{
 		sum += ctoi(source[i]) * weight;
 		weight++;
@@ -408,13 +408,13 @@ int isbn(struct zint_symbol *symbol, unsigned char source[], char dest[]) /* Mak
 	}
 
 	/* Input must be 9, 10 or 13 characters */
-	if(((strlen(source) < 9) || (strlen(source) > 13)) || ((strlen(source) > 10) && (strlen(source) < 13)))
+	if(((ustrlen(source) < 9) || (ustrlen(source) > 13)) || ((ustrlen(source) > 10) && (ustrlen(source) < 13)))
 	{
 		strcpy(symbol->errtxt, "error: input wrong length");
 		return ERROR_TOO_LONG;
 	}
 
-	if(strlen(source) == 13) /* Using 13 character ISBN */
+	if(ustrlen(source) == 13) /* Using 13 character ISBN */
 	{
 		if(!(((source[0] == '9') && (source[1] == '7')) &&
 				     ((source[2] == '8') || (source[2] == '9'))))
@@ -424,7 +424,7 @@ int isbn(struct zint_symbol *symbol, unsigned char source[], char dest[]) /* Mak
 		}
 
 		check_digit = isbn13_check(source);
-		if (source[strlen(source) - 1] != check_digit)
+		if (source[ustrlen(source) - 1] != check_digit)
 		{
 			strcpy(symbol->errtxt, "error: incorrect ISBN check");
 			return ERROR_INVALID_CHECK;
@@ -434,10 +434,10 @@ int isbn(struct zint_symbol *symbol, unsigned char source[], char dest[]) /* Mak
 		ean13(symbol, source, dest);
 	}
 
-	if(strlen(source) == 10) /* Using 10 digit ISBN */
+	if(ustrlen(source) == 10) /* Using 10 digit ISBN */
 	{
 		check_digit = isbn_check(source);
-		if(check_digit != source[strlen(source) - 1])
+		if(check_digit != source[ustrlen(source) - 1])
 		{
 			strcpy(symbol->errtxt, "error: incorrect ISBN check");
 			return ERROR_INVALID_CHECK;
@@ -454,7 +454,7 @@ int isbn(struct zint_symbol *symbol, unsigned char source[], char dest[]) /* Mak
 		ean13(symbol, source, dest);
 	}
 
-	if(strlen(source) == 9) /* Using 9 digit SBN */
+	if(ustrlen(source) == 9) /* Using 9 digit SBN */
 	{
 		/* Add leading zero */
 		for(i = 10; i > 0; i--)
@@ -465,7 +465,7 @@ int isbn(struct zint_symbol *symbol, unsigned char source[], char dest[]) /* Mak
 
 		/* Verify check digit */
 		check_digit = isbn_check(source);
-		if(check_digit != source[strlen(source) - 1])
+		if(check_digit != source[ustrlen(source) - 1])
 		{
 			strcpy(symbol->errtxt, "error: incorrect SBN check");
 			return ERROR_INVALID_CHECK;
@@ -503,7 +503,7 @@ int eanx(struct zint_symbol *symbol, unsigned char source[])
 	latch = FALSE;
 	writer = 0;
 
-	if(strlen(source) > 19) {
+	if(ustrlen(source) > 19) {
 		strcpy(symbol->errtxt, "error: input too long");
 		return ERROR_TOO_LONG;
 	}
@@ -516,7 +516,7 @@ int eanx(struct zint_symbol *symbol, unsigned char source[])
 		}
 	}
 	
-	for(reader = 0; reader <= strlen(source); reader++)
+	for(reader = 0; reader <= ustrlen(source); reader++)
 	{
 		if(source[reader] == '+') { with_addon = TRUE; }
 	}
@@ -540,7 +540,7 @@ int eanx(struct zint_symbol *symbol, unsigned char source[])
 				reader++;
 				writer++;
 			}
-		} while (reader <= strlen(source));
+		} while (reader <= ustrlen(source));
 	} else {
 		strcpy(first_part, source);
 	}
diff --git a/backend/zint.h b/backend/zint.h
index 64e6c03d..2244d584 100644
--- a/backend/zint.h
+++ b/backend/zint.h
@@ -142,6 +142,7 @@ extern int ZBarcode_Delete(struct zint_symbol *symbol);
 extern int ZBarcode_Encode(struct zint_symbol *symbol, unsigned char *input);
 extern int ZBarcode_Print(struct zint_symbol *symbol);
 extern int ZBarcode_Encode_and_Print(struct zint_symbol *symbol, unsigned char *input);
+extern int ZBarcode_Encode_and_Print_Rotated(struct zint_symbol *symbol, unsigned char *input, int rotate_angle);
 
 #ifdef __cplusplus
 }