Guix

hungrycat prints the contents of a file to standard output, while simultaneously freeing the disk space it occupied. It is useful if you need to process a large file, don't have enough space to store both the input and output files, and don't need the input file afterwards. While similar in principle to running cat immediately followed by rm, hungrycat actually frees blocks as soon as they are printed instead of after the entire file has been read, which is often too late.