I've always thought about collecting random bits of useful/interesting/cool Unix features and the like. Before I let that rot indefinitely in a text file in my $HOME, I'll post it in a series of blog posts. So here's bit #1:

Everyone knows /dev/null, and most will know /dev/zero. But /dev/full was unknown to me until some time ago. This device will respond to any write request with ENOSPC, No space left on device. Handy if you want to test if your program catches "disk full" - just let it write there:

$ echo foo > /dev/full
bash: echo: write error: No space left on device