int ezStringUtils::vsnprintf(char* szOutputBuffer, unsigned int uiBufferSize, const char* szFormat, va_list args0)
{
va_list args;
va_copy(args, args0);
EZ_ASSERT(ezUnicodeUtils::IsValidUtf8(szFormat), "The sprintf format string must be valid Utf8.");
// make sure the last character is a \0
if ((szOutputBuffer) && (uiBufferSize > 0))
szOutputBuffer[uiBufferSize - 1] = '\0';
unsigned int uiReadPos = 0;
unsigned int uiWritePos = 0;
bool bError = false;
while (szFormat[uiReadPos] != '\0')
{
const char c = szFormat[uiReadPos];
++uiReadPos;
// if c is not %, just print it out and be done with it
if (c != '%')
{
OutputChar (szOutputBuffer, uiBufferSize, uiWritePos, c);
continue;
}
// otherwise parse the formatting string to find out what has to be done
char cNext = szFormat[uiReadPos];
// *** parse the format string ***
// first read the flags (as many as there are)
unsigned int Flags = ReadFlags (szFormat, uiReadPos, cNext);
// read the width of the field
int iWidth = ReadWidth (szFormat, uiReadPos, cNext);
// read the precision specifier
int iPrecision = ReadPrecision (szFormat, uiReadPos, cNext);
// read the input data 'length' (short / int / long it, float / double)
const sprintfLength::Enum Length = ReadLength (szFormat, uiReadPos, cNext);
// read the 'specifier' type
const char cSpecifier = ReadSpecifier (szFormat, uiReadPos, cNext, bError);
if (bError)
{
snprintf (szOutputBuffer, uiBufferSize, "Error in formatting string at position %u ('%c').", uiReadPos, cSpecifier);
va_end(args);
return -1;
}
// if 'width' was specified as '*', read it from an extra parameter
if (iWidth < 0)
iWidth = va_arg (args, int);
// if 'precision' was specified as '*', read it from an extra parameter
if (iPrecision == -2)
iPrecision = va_arg (args, int);
// % Sign
if (cSpecifier == '%')
{
OutputChar (szOutputBuffer, uiBufferSize, uiWritePos, '%');
continue;
}
// Nothing: Writes the current write position back to an int pointer
if (cSpecifier == 'n')
{
int* p = va_arg (args, int*);
if (p)
*p = (int) uiWritePos;
continue;
}
// String
if (cSpecifier == 's')
{
const char* s = va_arg (args, const char*);
OutputString (szOutputBuffer, uiBufferSize, uiWritePos, s, Flags, iWidth, iPrecision);
continue;
}
// Character
if (cSpecifier == 'c')
{
char c2 = va_arg (args, int);
char s[2] = {c2, 0};
OutputString (szOutputBuffer, uiBufferSize, uiWritePos, s, Flags, iWidth, iPrecision);
continue;
}
void ReadLeaders() {
ReadFlags();
ReadWidth();
if (*format_ == '.') ReadPrecision();
ReadModifiers();
}
