diff --git a/tools/cws2fws.c b/tools/cws2fws.c index 8dc285bfff..c7b62df910 100644 --- a/tools/cws2fws.c +++ b/tools/cws2fws.c @@ -128,8 +128,8 @@ int main(int argc, char *argv[]) buf_in[2] = ((zstream.total_out + 8) >> 16) & 0xff; buf_in[3] = ((zstream.total_out + 8) >> 24) & 0xff; - lseek(fd_out, 4, SEEK_SET); - if (write(fd_out, &buf_in, 4) < 4) { + if ( lseek(fd_out, 4, SEEK_SET) < 0 + || write(fd_out, &buf_in, 4) < 4) { perror("Error writing output file"); return 1; }