tee - Duplicate the output stream

Format

tee [-ai] [file ... file ...]

Description

tee clones an output stream. It copies the standard input to each output file as well as to the standard output.

Options

-a
Appends to (rather than overwrites) each output file.
-i
Ignores interrupt signals, making it suitable for use as a background process.

Examples

The following command runs the program prog and pipes the program's standard output into tee: 
prog | tee file

As a result, tee writes the output to both the standard output and the specified file.

Localization

tee uses the following localization environment variables:
  • LANG
  • LC_ALL
  • LC_CTYPE
  • LC_MESSAGES
  • NLSPATH

Exit values

0
Successful completion.
1
Failure due to any of the following reasons:
  • Out of memory when I/O buffers are allocated.
  • I/O error reading or writing to a file.
  • Error creating an output file.
  • Error opening an output file for appending.
2
Failure due to incorrect command-line option.

Portability

POSIX.2, X/Open Portability Guide, UNIX systems.

Related information

cat, script