Im emacs, I want to run "touch" on the file referenced by the current buffer (specifically want to change the modification time). I use guard to run some tests after files are changed, but sometimes I want to invoke it manually. I don't care about running the actual shell utility touch so long as mtime is set.
!["Touch" current file in emacs](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)