Unix and Linux Stack Exchange
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Questions tagged [tee]

tee is a command line utility that reads the standard input and writes to the standard output as well as a file specified as an argument. Use this tag for questions about the tee command.

tee is a standard utility that reads from standard input and writes the same output to standard output and files given on the command line.

Example

Taking simple file as this:

$ cat file
AAA
AAAA
AAAAA

These commands will count the rows in the file and write it in file_tee. If file_tee is not empty the contents would be truncated.

$ wc -l file | tee file_tee
3 file

Further reading

221 questions
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how to redirect output to multiple log files

How to redirect standard output to multiple log files? The following does not work: some_command 1> output_log_1 output_log_2 2>&1
doubledecker
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Using exec and tee to redirect logs to stdout and a log file in the same time

In a bash script, how can I redirect all standard outputs to a log file and tee the output on the screen using exec ? log_file="$HOME/logs/install.txt-`date +'%Y-%m-%d_%H-%M-%S'`" [ -f "$log_file" ] || touch "$log_file" exec 1>> $log_file 2>&1 This…
4m1nh4j1
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Direct output to pipe and stdout

Is there a way to pipe the output of a command and direct it to the stdout as well? So for example, fortune prints a fortune cookie to stdout and also pipes it to next command: $ fortune | tee >(?stdout?) | pbcopy "...Unix, MS-DOS, and Windows NT…
user14492
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using tee to output intermediate results to stdout instead of files

I know that to capture a pipeline's contents at an intermediate stage of processing, we use tee as ls /bin /usr/bin | sort | uniq | tee abc.txt | grep out , but what if i don't want to redirect the contents after uniq to abc.txt but to…
Aman
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Output to stdout and at the same time grep into a file

I have a script that outputs text to stdout. I want to see all this output in my terminal, and at the same time I want to filter some lines and save them in a file. Example: $ myscript Line A Line B Line C $ myscript | grep -P 'A|C' > out.file $…
lorenzo-s
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How does `:w !sudo tee %` work

If you open a file that you don't have permission to write to in vim, then decide you need to change it, you can write your changes without exiting vim by doing :w !sudo tee % I don't understand how this can work. Can you please dissect this? I…
Ali
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Why does 'ping' not output a summary when redirecting output?

I can ping google.com for several seconds and when I press Ctrl + C, a brief summary is displayed at the bottom: $ ping google.com PING google.com (74.125.131.113) 56(84) bytes of data. 64 bytes from lu-in-f113.1e100.net (74.125.131.113): icmp_seq=2…
ks1322
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tee + cat: use an output several times and then concatenate results

If I call some command, for instance an echo I can use the results from that command in several other commands with tee. Example: echo "Hello world!" | tee >(command1) >(command2) >(command3) With cat I can collect the results of several commands.…
Trylks
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tee stdout to stderr?

I'd like to send stdout from one process to the stdin of another process, but also to the console. Sending stdout to stdout+stderr, for instance. For example, I've got git edit aliased to the following: git status --short | cut -b4- | xargs gvim…
Roger Lipscombe
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Is it possible to redirect the output of a command into more than one command?

As far as I know, I can use the tee command to split the standard output onto the screen and further files: command -option1 -option2 argument | tee file1 file2 file3 Is it possible to redirect the output to commands instead of files using tee, so…
Abdul Al Hazred
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Use sudo tee with heredoc to append to existing file

From Generate script in bash and save it to location requiring sudo we have this method, which I like: sudo tee "$OUTFILE" > /dev/null <<'EOF' foo bar EOF However, I would like to use that approach to append to an existing file $OUTFILE. The above…
MountainX
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Is there any difference between tee and >> when using echo?

Is there any difference beteween doing: echo "hahaha" >> file1 and echo "hahaha" |tee -a file1 ? Yes, I noticed that I cannot write to write protected files even aith sudo echo, but I can if I sudo tee. Thanks.
iamAguest
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How to terminate Linux tee command without killing application it is receiving from

I have a bash script that runs as long as the Linux machine is powered on. I start it as shown below: ( /mnt/apps/start.sh 2>&1 | tee /tmp/nginx/debug_log.log ) & After it lauches, I can see the tee command in my ps output as shown below: $ ps |…
PhilBot
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Why does `echo 'hi' | tee > a b c` create multiple files, whereas `echo 'hi' > a b c` doesn't?

My env: zsh, macOS Command in concern: echo 'hi' | tee > a b c echo 'hi' > a b c Command 1 creates files named a, b and c with content hi. Command 2 creates a file named a with content hi b c. AFAIK, only the usage of Command 1 without > is…
catwith
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`tee` for commands

tee can redirect the piped standard input into the standard output and file. echo Hello, World! | tee greeting.txt The command above would display the greeting on the terminal screen and save it in the contents of greeting.txt file, creating the…
user86041
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