The Sponge and Tee Command

From Linux man:

sponge - soak up standard input and write to a file

Synopsis

sed '...' file | grep '...' | sponge file

Description

`sponge reads standard input and writes it out to the specified file. Unlike a shell redirect, sponge soaks up all its input before opening the output file. This allows constricting pipelines that read from and write to the same file.

If no output file is specified, sponge outputs to stdout.

The Tee and Sponge commands difference:

sponge soaks up all its input before opening the output file. tee "reads a byte", and "writes that byte"; 'sponge' waits to receive all the input, and then, writes it.