Function V_stristr

src/vstdlib/strtools.cpp:159–200

----------------------------------------------------------------------------- Finds a string in another string with a case insensitive test -----------------------------------------------------------------------------

// Finds a string in another string with a case insensitive test
//-----------------------------------------------------------------------------
char const* V_stristr( char const* pStr, char const* pSearch )
{
	Assert( pStr != NULL );
	Assert( pSearch != NULL );

	if ( pStr == NULL || pSearch == NULL ) 
		return NULL;

	char const* pLetter = pStr;

	// Check the entire string
	while ( *pLetter != 0 )
	{
		// Skip over non-matches
		if ( tolower( (unsigned char) *pLetter ) == tolower( (unsigned char) *pSearch ) )
		{
			// Check for match
			char const* pMatch = pLetter + 1;
			char const* pTest = pSearch + 1;
			while (*pTest != 0)
			{
				// We've run off the end; don't bother.
				if (*pMatch == 0)
					return 0;

				if ( tolower( (unsigned char) *pMatch ) != tolower( (unsigned char) *pTest ) )
					break;

				++pMatch;
				++pTest;
			}

			// Found a match!
			if ( *pTest == 0 )
				return pLetter;
		}

		++pLetter;
	}

	return 0;
}

//-----------------------------------------------------------------------------
// Purpose: Convert ASCII characters to lower case in-place