DOKK / manpages / debian 11 / 9base / tee.1plan9.en
TEE(1plan9) TEE(1plan9)

tee - pipe fitting

tee [ -i ] [ -a ] files

Tee transcribes the standard input to the standard output and makes copies in the files. The options are

Ignore interrupts.
Append the output to the files rather than rewriting them.

/src/cmd/tee.c