This program can be used to prevent doomed TeX Live update attempts on windows by testing whether all files concerned can be opened with exclusive read/write access. It reads a list of absolute filepaths from stdin and errors out if any of them cannot be opened with exclusive read/write access. A -v option also produces status output on stdout. Cross-compiling under linux: i686-w64-mingw32-gcc -o wtestopenfiles.exe wtestopenfiles.c i686-w64-mingw32-strip wtestopenfiles.exe