munchcat

a simple program that works kind of like cat(1) but EATS the files

"eating" a file means, after a piece of the file is read and printed, a hole is punched in the space that was just read, making a sparse file that gets smaller as the file is being read

this is of course very destructive to the file, but useful if you munchcat a single very large file and redirect the output to a file on another filesystem (but maybe on the same disk drive), as the data will be moved without significantly increasing disk usage at any point in the process.