Add 'fromString(const char*)', 'fromString(const String)' to IPAddress class (espressif#68)

Author: minyk

cores/esp32/IPAddress.cpp

@@ -79,3 +79,44 @@ String IPAddress::toString()
  return String(szRet);
 }
 
+bool IPAddress::fromString(const char *address)
+{
+ // TODO: add support for "a", "a.b", "a.b.c" formats
+
+ uint16_t acc = 0; // Accumulator
+ uint8_t dots = 0;
+
+ while (*address)
+ {
+ char c = *address++;
+ if (c >= '0' && c <= '9')
+ {
+ acc = acc * 10 + (c - '0');
+ if (acc > 255) {
+ // Value out of [0..255] range
+ return false;
+ }
+ }
+ else if (c == '.')
+ {
+ if (dots == 3) {
+ // Too much dots (there must be 3 dots)
+ return false;
+ }
+ _address.bytes[dots++] = acc;
+ acc = 0;
+ }
+ else
+ {
+ // Invalid char
+ return false;
+ }
+ }
+
+ if (dots != 3) {
+ // Too few dots (there must be 3 dots)
+ return false;
+ }
+ _address.bytes[3] = acc;
+ return true;
+}

cores/esp32/IPAddress.h

@@ -51,6 +51,9 @@ class IPAddress: public Printable
  IPAddress(const uint8_t *address);
  virtual ~IPAddress() {}
 
+ bool fromString(const char *address);
+ bool fromString(const String &address) { return fromString(address.c_str()); }
+
  // Overloaded cast operator to allow IPAddress objects to be used where a pointer
  // to a four-byte uint8_t array is expected
  operator uint32_t() const