Tee (command)

tee is a shell command that copies data from standard input to one or more files in addition to standard output, duplicating the input to each output. The name derives from the tee pipe fitting even though the tee command duplicates the input into each output instead of dividing the input into portions for each output. The command is often used with pipes and filters. Similar behaving commands are provided by many shells although syntax varies. The command is provided in Unix and Unix-like systems, OS-9, MS-DOS / PC DOS and compatibles, Windows (e.g. 4NT, PowerShell, UnxUtils), ReactOS and IBM i. The Linux version was written by Mike Parker, Richard Stallman, and David MacKenzie. The FreeDOS version was developed by Jim Hall and is licensed under the GPL. Additionally the sponge command offers similar capabilities. The typical syntax on a Unix-based system can be described as: Process substitution lets more than one process read the standard output of the originating process. If a write to any file is not successful, writes to other files and standard output continue, but the exit status will indicate failure with a value greater than 0.