Feature/bacnet-str-itoa-helpers (#1157)

* Added BACnet library itoa, ltoa, ultoa, dtoa, and utoa ASCII functions for ease of printing formatted values.

* Exposed the bacnet_byte_reverse_bits() function API.

CHANGELOG.md

@@ -17,6 +17,8 @@ The git repositories are hosted at the following sites:
 ### Security
 ### Added
 
+* Added BACnet library itoa, ltoa, ultoa, dtoa, and utoa ASCII
+  functions for ease of printing formatted values. (#1157)
 * Added library specific string-to functions similar to stdlib.
   Added library specific string-to functions for BACnet primitives. (#1151)
 

src/bacnet/bacdcode.c

@@ -1466,12 +1466,10 @@ int bacnet_null_context_decode(
 
 /**
  * @brief Reverse the bits of the given byte.
- *
  * @param in_byte  Byte to reverse.
- *
  * @return Byte with reversed bit order.
  */
-static uint8_t byte_reverse_bits(uint8_t in_byte)
+uint8_t bacnet_byte_reverse_bits(uint8_t in_byte)
 {
     uint8_t out_byte = 0;
 
@@ -1534,7 +1532,8 @@ int decode_bitstring(
                 /* Copy the bytes in reversed bit order. */
                 for (i = 0; i < bytes_used; i++) {
                     bitstring_set_octet(
-                        bit_string, (uint8_t)i, byte_reverse_bits(apdu[len++]));
+                        bit_string, (uint8_t)i,
+                        bacnet_byte_reverse_bits(apdu[len++]));
                 }
                 /* Erase the remaining unused bits. */
                 unused_bits = (uint8_t)(apdu[0] & 0x07);
@@ -1581,7 +1580,7 @@ int bacnet_bitstring_decode(
                 /* Copy the bytes in reversed bit order. */
                 for (i = 0; i < bytes_used; i++) {
                     bitstring_set_octet(
-                        value, (uint8_t)i, byte_reverse_bits(apdu[len]));
+                        value, (uint8_t)i, bacnet_byte_reverse_bits(apdu[len]));
                     len++;
                 }
                 /* Erase the remaining unused bits. */
@@ -1775,7 +1774,8 @@ int encode_bitstring(uint8_t *apdu, const BACNET_BIT_STRING *bit_string)
         len++;
         for (i = 0; i < used_bytes; i++) {
             if (apdu) {
-                apdu[len] = byte_reverse_bits(bitstring_octet(bit_string, i));
+                apdu[len] =
+                    bacnet_byte_reverse_bits(bitstring_octet(bit_string, i));
             }
             len++;
         }

src/bacnet/bacdcode.h

@@ -242,6 +242,8 @@ int bacnet_bitstring_decode(
     uint32_t apdu_len_max,
     uint32_t len_value,
     BACNET_BIT_STRING *value);
+BACNET_STACK_EXPORT
+uint8_t bacnet_byte_reverse_bits(uint8_t in_byte);
 
 BACNET_STACK_EXPORT
 int bacnet_bitstring_application_encode(

src/bacnet/bacstr.c

@@ -1775,3 +1775,85 @@ bool bacnet_string_to_unsigned(
 
     return true;
 }
+
+/**
+ * @brief General purpose print formatter which returns the formatted string
+ * @param buffer - destination string
+ * @param count - length of the destination string
+ * @param format - format string
+ * @return character string buffer
+ */
+char *
+bacnet_sprintf_to_ascii(char *buffer, size_t size, const char *format, ...)
+{
+    va_list args;
+
+    va_start(args, format);
+    /* The vsnprintf function always writes a null terminator,
+       even if it truncates the output. */
+    (void)vsnprintf(buffer, size, format, args);
+    va_end(args);
+
+    return buffer;
+}
+
+/**
+ * @brief Convert a value into a string and return the base-10 string
+ * @param value Number to be converted.
+ * @param buffer Buffer that holds the result of the conversion.
+ * @param size Length of the buffer in units of the character type.
+ * @param precision Number of decimal places
+ * @return character string buffer
+ */
+char *bacnet_dtoa(double value, char *buffer, size_t size, unsigned precision)
+{
+    return bacnet_sprintf_to_ascii(buffer, size, "%.*f", precision, value);
+}
+
+/**
+ * @brief Convert a value into a string and return the base-10 string
+ * @param value Number to be converted.
+ * @param buffer Buffer that holds the result of the conversion.
+ * @param size Length of the buffer in units of the character type.
+ * @return character string buffer
+ */
+char *bacnet_itoa(int value, char *buffer, size_t size)
+{
+    return bacnet_sprintf_to_ascii(buffer, size, "%d", value);
+}
+
+/**
+ * @brief Convert a value into a string and return the base-10 string
+ * @param value Number to be converted.
+ * @param buffer Buffer that holds the result of the conversion.
+ * @param size Length of the buffer in units of the character type.
+ * @return character string buffer
+ */
+char *bacnet_ltoa(long value, char *buffer, size_t size)
+{
+    return bacnet_sprintf_to_ascii(buffer, size, "%ld", value);
+}
+
+/**
+ * @brief Convert a value into a string and return the base-10 string
+ * @param value Number to be converted.
+ * @param buffer Buffer that holds the result of the conversion.
+ * @param size Length of the buffer in units of the character type.
+ * @return character string buffer
+ */
+char *bacnet_utoa(unsigned value, char *buffer, size_t size)
+{
+    return bacnet_sprintf_to_ascii(buffer, size, "%u", value);
+}
+
+/**
+ * @brief Convert a value into a string and return the base-10 string
+ * @param value Number to be converted.
+ * @param buffer Buffer that holds the result of the conversion.
+ * @param size Length of the buffer in units of the character type.
+ * @return character string buffer
+ */
+char *bacnet_ultoa(unsigned long value, char *buffer, size_t size)
+{
+    return bacnet_sprintf_to_ascii(buffer, size, "%lu", value);
+}

src/bacnet/bacstr.h

@@ -205,6 +205,20 @@ BACNET_STACK_EXPORT
 bool bacnet_string_to_unsigned(
     const char *str, BACNET_UNSIGNED_INTEGER *unsigned_int);
 
+BACNET_STACK_EXPORT
+char *bacnet_dtoa(double value, char *buffer, size_t size, unsigned precision);
+BACNET_STACK_EXPORT
+char *bacnet_itoa(int value, char *buffer, size_t size);
+BACNET_STACK_EXPORT
+char *bacnet_ltoa(long value, char *buffer, size_t size);
+BACNET_STACK_EXPORT
+char *bacnet_utoa(unsigned value, char *buffer, size_t size);
+BACNET_STACK_EXPORT
+char *bacnet_ultoa(unsigned long value, char *buffer, size_t size);
+BACNET_STACK_EXPORT
+char *
+bacnet_sprintf_to_ascii(char *buffer, size_t count, const char *format, ...);
+
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */