## Demonstrate proficiency in using redirection, pipes and tees ##

[Author](authors.html): _name_ _[[contact]]_ _[[BSD_flavour]]_

[Reviewer](technical_reviewers.html): _name_ _[[contact]]_ _[[BSD_flavour]]_

[Reviewer](technical_reviewers.html): _name_ _[[contact]]_ _[[BSD_flavour]]_

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### Concept ###

Be able to to redirect standard input(((standard input))),
output(((standard output))) or error(((standard error))), use
a pipe(((pipe))) to send the output of one command to another command
or file, and use a tee to copy standard input to standard output.


### Introduction ###


tee: pipe fitting, this utility copies standard input to standard output, making a copy in zero or more files. The output is unbuffered.

file descriptors (fd):

fd 0: stdin

fd 1: stdout

fd 2: stderr

<: redirect stdin of a process so that input is read from a file instead of from the keyboard

command < infile

\>: redirects stdout to a file

command > outfile

\>\>: appends stdout to a file

command >> outfile

| : piping command output to another command

command1 | command2 | ... | commandN

tee: lets you divert a copy of the data passing between commands to a file without changing how the pipeline functions

who | tee savewho | wc -l

\>&: temporarily connect something to something else

ls 2>&1 means temporarily connect stderr to stdout

|&: 



### Examples ###


### Practice Exercises ###


### More information ###

<, >, |, tee(1), >\& and |\&


