Move escape character processing into library

And expand to include all 8-bit values.

backend/common.c

@@ -43,7 +43,11 @@ size_t ustrlen(const unsigned char data[]) {
 int ctoi(const char source) {
     if ((source >= '0') && (source <= '9'))
         return (source - '0');
+    if ((source >= 'A') && (source <= 'F'))
         return (source - 'A' + 10);
+    if ((source >= 'a') && (source <= 'f'))
+        return (source - 'a' + 10);
+    return -1;
 }
 
 

backend/library.c

@@ -57,7 +57,7 @@ struct zint_symbol *ZBarcode_Create() {
     symbol->width = 0;
     strcpy(symbol->fgcolour, "000000");
     strcpy(symbol->bgcolour, "ffffff");
-    strcpy(symbol->outfile, "");
+    strcpy(symbol->outfile, "out.png");
     symbol->scale = 1.0;
     symbol->option_1 = -1;
     symbol->option_2 = 0;
@@ -792,7 +792,96 @@ void strip_bom(unsigned char *source, int *input_length) {
     }
 }
 
-int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source,int in_length) {
+int escape_char_process(struct zint_symbol *symbol, unsigned char *input_string, int *length) {
+    int error_number;
+    int in_posn, out_posn;
+    int hex1, hex2;
+
+#ifndef _MSC_VER
+    unsigned char escaped_string[*length + 1];
+#else
+    unsigned char* escaped_string = (unsigned char*) _alloca(length + 1);
+#endif
+
+    in_posn = 0;
+    out_posn = 0;
+
+    do {
+        if (input_string[in_posn] == '\\') {
+            switch (input_string[in_posn + 1]) {
+                case '0': escaped_string[out_posn] = 0x00; /* Null */
+                    in_posn += 2;
+                    break;
+                case 'E': escaped_string[out_posn] = 0x04; /* End of Transmission */
+                    in_posn += 2;
+                    break;
+                case 'a': escaped_string[out_posn] = 0x07; /* Bell */
+                    in_posn += 2;
+                    break;
+                case 'b': escaped_string[out_posn] = 0x08; /* Backspace */
+                    in_posn += 2;
+                    break;
+                case 't': escaped_string[out_posn] = 0x09; /* Horizontal tab */
+                    in_posn += 2;
+                    break;
+                case 'n': escaped_string[out_posn] = 0x0a; /* Line feed */
+                    in_posn += 2;
+                    break;
+                case 'v': escaped_string[out_posn] = 0x0b; /* Vertical tab */
+                    in_posn += 2;
+                    break;
+                case 'f': escaped_string[out_posn] = 0x0c; /* Form feed */
+                    in_posn += 2;
+                    break;
+                case 'r': escaped_string[out_posn] = 0x0d; /* Carriage return */
+                    in_posn += 2;
+                    break;
+                case 'e': escaped_string[out_posn] = 0x1b; /* Escape */
+                    in_posn += 2;
+                    break;
+                case 'G': escaped_string[out_posn] = 0x1d; /* Group Separator */
+                    in_posn += 2;
+                    break;
+                case 'R': escaped_string[out_posn] = 0x1e; /* Record Separator */
+                    in_posn += 2;
+                    break;
+                case 'x': if (in_posn + 4 > *length) {
+                        strcpy(symbol->errtxt, "232: Incomplete escape character in input data");
+                        return ZINT_ERROR_INVALID_DATA;
+                    }
+                    hex1 = ctoi(input_string[in_posn + 2]);
+                    hex2 = ctoi(input_string[in_posn + 3]);
+                    if ((hex1 >= 0) && (hex2 >= 0)) {
+                        escaped_string[out_posn] += (hex1 << 4) + hex2;
+                        in_posn += 4;
+                    } else {
+                        strcpy(symbol->errtxt, "233: Corrupt escape character in input data");
+                        return ZINT_ERROR_INVALID_DATA;
+                    }
+                    break;
+                case '\\': escaped_string[out_posn] = '\\';
+                    in_posn += 2;
+                    break;
+                default: strcpy(symbol->errtxt, "234: Unrecognised escape character in input data");
+                    return ZINT_ERROR_INVALID_DATA;
+                    break;
+            }
+        } else {
+            escaped_string[out_posn] = input_string[in_posn];
+            in_posn++;
+        }
+        out_posn++;
+    } while (in_posn < *length);
+
+    memcpy(input_string, escaped_string, out_posn);
+    *length = out_posn;
+    
+    error_number = 0;
+
+    return error_number;
+}
+
+int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int in_length) {
     int error_number, error_buffer, i;
 #ifdef _MSC_VER
     unsigned char* local_source;
@@ -967,14 +1056,7 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source,int
         error_number = ZINT_ERROR_INVALID_OPTION;
     }
 
-    if ((symbol->input_mode < 0) || (symbol->input_mode > 2)) {
+    /* Start acting on input mode */
-        symbol->input_mode = DATA_MODE;
-    }
-    
-    if ((symbol->eci != 3) && (symbol->eci != 26)) {
-        symbol->input_mode = DATA_MODE;
-    }
-
     if (symbol->input_mode == GS1_MODE) {
         for (i = 0; i < in_length; i++) {
             if (source[i] == '\0') {
@@ -997,6 +1079,22 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source,int
         local_source[in_length] = '\0';
     }
     
+    if (symbol->input_mode &= ESCAPE_MODE) {
+        error_number = escape_char_process(symbol, local_source, &in_length);
+        if (error_number != 0) {
+            return error_number;
+        }
+        symbol->input_mode -= ESCAPE_MODE;
+    }
+    
+    if ((symbol->input_mode < 0) || (symbol->input_mode > 2)) {
+        symbol->input_mode = DATA_MODE;
+    }
+    
+    if ((symbol->eci != 3) && (symbol->eci != 26)) {
+        symbol->input_mode = DATA_MODE;
+    }
+    
     if (symbol->input_mode == UNICODE_MODE) {
         strip_bom(local_source, &in_length);
     }

backend/zint.h

@@ -220,6 +220,7 @@ extern "C" {
 #define GS1_MODE	2
 #define KANJI_MODE	3
 #define SJIS_MODE	4
+#define ESCAPE_MODE     8
 
 // Data Matrix specific options
 #define DM_SQUARE	100

docs/manual.txt

@@ -179,12 +179,12 @@ Unicode then you will need to set the appropriate input options as shown in
 section 4.11 below. 
 
 Non-printing characters can be entered on the command line using the backslash 
-(\) as an escape character. Permissible characters are shown in the table 
+(\) as an escape character in combination with the --esc switch. Permissible
-below. Note that this only applies on the command line. 
+characters are shown in the table below. 
 
--------------------------------------------------------------
+--------------------------------------------------------------------
 Escape Character  |  ASCII Equivalent  |  Interpretation
--------------------------------------------------------------
+--------------------------------------------------------------------
 \0                |  0x00              |  Null
 \E                |  0x04              |  End of Transmission
 \a                |  0x07              |  Bell
@@ -197,7 +197,9 @@ Escape Character  |  ASCII Equivalent  |  Interpretation
 \e                |  0x1B              |  Escape
 \G                |  0x1D              |  Group Selector
 \R                |  0x1E              |  Record Selector
--------------------------------------------------------------
+\xNN              |  0xNN              |  Any other 8-bit character
+                  |                    |     where NN is hexadecimal
+--------------------------------------------------------------------
 
 Input data can be read directly from file using the -i switch as shown below. 
 The input file is assumed to be Unicode (UTF-8) formatted unless an alternative 
@@ -1042,8 +1044,21 @@ Value         |  Effect
 DATA_MODE     |  Uses full ASCII range interpreted as Latin-1 or binary data.
 UNICODE_MODE  |  Uses pre-formatted UTF-8 input.
 GS1_MODE      |  Encodes GS1 data using FNC1 characters.
+ESCAPE_MODE   |  Process input data for escape sequences
 -----------------------------------------------------------------------------
 
+DATA_MODE, UNICODE_MODE and GS1_MODE are mutually exclusive, whereas
+ESCAPE_MODE is optional. So, for example, you can set
+
+my_symbol->input_mode = UNICODE_MODE + ESCAPE_MODE;
+
+whereas 
+
+my_symbol->input_mode = DATA_MODE + GS1_MODE;
+
+is not valid. Permissable escape sequences are listed in section 4.1.
+
+
 5.10 Verifying Symbology Availability
 -------------------------------------
 An additional function available in the API is defined as:

frontend/main.c

@@ -92,6 +92,7 @@ void usage(void) {
             "  --dump                Dump hexadecimal representation to stdout\n"
             "  -e, --ecinos          Display table of ECI character encodings\n"
             "  --eci=NUMBER          Set the ECI mode for raw data\n"
+            "  --esc                 Process escape characters in input data\n"
             "  --filetype=TYPE       Set output file type (PNG/EPS/SVG/PNG/EPS/GIF/TXT)\n"
             "  --fg=COLOUR           Specify a foreground colour (in hex)\n"
             "  --gs1                 Treat input as GS1 compatible data\n"
@@ -168,78 +169,6 @@ int validator(char test_string[], char source[]) {
     return 0;
 }
 
-int escape_char_process(struct zint_symbol *my_symbol, unsigned char input_string[], int length) {
-    int error_number;
-    int i, j;
-
-#ifndef _MSC_VER
-    unsigned char escaped_string[length + 1];
-#else
-    unsigned char* escaped_string = (unsigned char*) _alloca(length + 1);
-#endif
-
-    i = 0;
-    j = 0;
-
-    do {
-        if (input_string[i] == '\\') {
-            switch (input_string[i + 1]) {
-                case '0': escaped_string[j] = 0x00; /* Null */
-                    i += 2;
-                    break;
-                case 'E': escaped_string[j] = 0x04; /* End of Transmission */
-                    i += 2;
-                    break;
-                case 'a': escaped_string[j] = 0x07; /* Bell */
-                    i += 2;
-                    break;
-                case 'b': escaped_string[j] = 0x08; /* Backspace */
-                    i += 2;
-                    break;
-                case 't': escaped_string[j] = 0x09; /* Horizontal tab */
-                    i += 2;
-                    break;
-                case 'n': escaped_string[j] = 0x0a; /* Line feed */
-                    i += 2;
-                    break;
-                case 'v': escaped_string[j] = 0x0b; /* Vertical tab */
-                    i += 2;
-                    break;
-                case 'f': escaped_string[j] = 0x0c; /* Form feed */
-                    i += 2;
-                    break;
-                case 'r': escaped_string[j] = 0x0d; /* Carriage return */
-                    i += 2;
-                    break;
-                case 'e': escaped_string[j] = 0x1b; /* Escape */
-                    i += 2;
-                    break;
-                case 'G': escaped_string[j] = 0x1d; /* Group Separator */
-                    i += 2;
-                    break;
-                case 'R': escaped_string[j] = 0x1e; /* Record Separator */
-                    i += 2;
-                    break;
-                case '\\': escaped_string[j] = '\\';
-                    i += 2;
-                    break;
-                default: escaped_string[j] = input_string[i];
-                    i++;
-                    break;
-            }
-        } else {
-            escaped_string[j] = input_string[i];
-            i++;
-        }
-        j++;
-    } while (i < length);
-    escaped_string[j] = '\0';
-
-    error_number = ZBarcode_Encode(my_symbol, escaped_string, j);
-
-    return error_number;
-}
-
 /* Converts an integer value to its hexadecimal character */
 static char itoc(int source) { 
     if ((source >= 0) && (source <= 9)) {
@@ -500,6 +429,7 @@ int main(int argc, char **argv) {
             {"dotsize", 1, 0, 0},
             {"eci", 1, 0, 0},
             {"filetype", 1, 0, 0},
+            {"esc", 0, 0, 0},
             {"verbose", 0, 0, 0}, // Currently undocumented, output some debug info
             {0, 0, 0, 0}
         };
@@ -696,6 +626,11 @@ int main(int argc, char **argv) {
                         fflush(stderr);
                     }
                 }
+                if (!strcmp(long_options[option_index].name, "esc")) {
+                    if (!(my_symbol->input_mode &= ESCAPE_MODE)) {
+                        my_symbol->input_mode += ESCAPE_MODE;
+                    }
+                }
                 if (!strcmp(long_options[option_index].name, "verbose")) {
                     my_symbol->debug = 1;
                 }
@@ -742,7 +677,7 @@ int main(int argc, char **argv) {
                         strcat(my_symbol->outfile, ".");
                         strcat(my_symbol->outfile, filetype);
                     }
-                    error_number = escape_char_process(my_symbol, (unsigned char*) optarg, strlen(optarg));
+                    error_number = ZBarcode_Encode(my_symbol, (unsigned char*) optarg, strlen(optarg));
                     if (error_number < 5) {
                         if (error_number != 0) {
                             fprintf(stderr, "%s\n", my_symbol->errtxt);