Function fopenGzipped

LASlib/src/fopen_compressed.cpp:152–224

}

static FILE* fopenGzipped(const char* filename, const char* mode)
{
	// check mode
	if (mode[0] == 'r')
	{
		// open input file
		FILE* gzipInput = LASfopen(filename, mode);
		if (!gzipInput) return NULL;

		// create the pipe
		int hPipe[2];
		if (_pipe(hPipe, 2048, ((mode[1] =='b') ? _O_BINARY : _O_TEXT) | _O_NOINHERIT) == -1)
		{
			laserror("could not create pipe");
			return NULL;
		}

		// duplicate stdin handle
		int hStdIn = _dup(_fileno(stdin));
		// redirect stdin to input file
		if (_dup2(_fileno(gzipInput), _fileno(stdin)) != 0)
		{
			laserror("could not redirect stdin");
			return NULL;
		}

		// duplicate stdout handle
		int hStdOut = _dup(_fileno(stdout));
		// redirect stdout to write end of pipe
		if (_dup2(hPipe[WRITE_HANDLE], _fileno(stdout)) != 0)
		{
			laserror("could not set pipe output");
			return NULL;
		}

		// close original write end of pipe
		_close(hPipe[WRITE_HANDLE]);

		// redirect read end of pipe to input file
		if (_dup2(hPipe[READ_HANDLE], _fileno(gzipInput)) != 0)
		{
			laserror("could not redirect input file");
			return NULL;
		}

		// close original read end of pipe
		_close(hPipe[READ_HANDLE]);

		// Spawn process
		HANDLE hProcess = (HANDLE)_spawnlp(P_NOWAIT, "gzip", "gzip", "-d", NULL);

		// redirect stdin back into stdin
		if (_dup2(hStdIn, _fileno(stdin)) != 0)
		{
			laserror("could not reconstruct stdin");
			return NULL;
		}