Pipe output to two different commands [duplicate]

It should be ok if you use both tee and mkfifo.

mkfifo pipecat pipe | (command 1) &echo 'test' | tee pipe | (command 2)

Recent bash present >(command) syntax:

echo "Hello world." | tee >(sed 's/^/1st: /')  >(sed 's/^/2nd cmd: /') >/dev/null

May return:

2nd cmd: Hello world.1st: Hello world.

download somefile.ext, save them, compute md5sum and sha1sum:

wget -O - http://somewhere.someland/somepath/somefile.ext |    tee somefile.ext >(md5sum >somefile.md5) | sha1sum >somefile.sha1

or

wget -O - http://somewhere.someland/somepath/somefile.ext |    tee >(md5sum >somefile.md5) >(sha1sum >somefile.sha1) >somefile.ext

Old answer

There is a way to do that via unnamed pipe (tested under linux):

 (( echo "hello" |         tee /dev/fd/5 |             sed 's/^/1st occure: /' >/dev/fd/4    ) 5>&1 |    sed 's/^/2nd command: /' ) 4>&1

give:

2nd command: hello1st occure: hello

This sample will let you download somefile.ext, save them, compute his md5sum and compute his sha1sum:

(( wget -O - http://somewhere.someland/somepath/somefile.ext |    tee /dev/fd/5 |    md5sum >/dev/fd/4  ) 5>&1 |  tee somefile.ext |  sha1sum) 4>&1

Maybe take a look at tee command. What it does is simply print its input to a file, but it also prints its input to the standard output. So something like:

echo "Hello" | tee try.txt | <some_command>

Will create a file with content "Hello" AND also let "Hello" (flow through the pipeline) end up as <some_command>'s STDIN.