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Jader Dias
Asked: 2009-07-17 18:59:10 +0800 CST

How can I hide the output of a shell application in Linux?

  • 772

How can I hide the screen output (printf) of a shell application in Linux?

linux shell

5 Answers

  1. Best Answer

    You can redirect the output of any program so that it won't be seen.

    $ program > /dev/null

    This will redirect the standard output - you'll still see any errors

    $ program &> /dev/null

    This will redirect all output, including errors.

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  2. There are three I/O devices available on the command line.

     standard input  - 0
 standard output - 1
 standard error  - 2

    To redirect standard output (the default output) to a file (and overwrite the file), use

     command > file.log

    To append to file.log, use two >s

     command >> file.log

    To redirect standard error to the file.log, use

     command 2> file.log

    And to append

     command 2>> file.log

    To combine the outputs into one stream and send them all to one place

     command > file.log 2>&1

    This sends 2 (standard error) into 1 (standard output), and sends standard output to file.log

    Notice that it's also possible to redirect standard input into a command that expects standard input

     command << file.txt


    For more details, check out the Advanced Bash Scripting Guide.

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  3. Hide standard output:

    ./command >/dev/null

    Hide standard and error outputs:

    ./command >/dev/null 2>&1

    Hide standard output and error outputs and release the terminal (run the command in the background):

    ./command >/dev/null 2>&1 &
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  4. If you just want to hide the output (and not save it to a file), you can use:

    Edited:

    $ command &> /dev/null

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  5. For Mac OS X v10.6 (Snow Leopard):

    If you need to hide the output without letting the program know it by checking the output/error file descriptor, you can try using the following in a shell:

    stty flusho; command ;stty -flusho

    or if you just want to hide input from the terminal by the way:

    stty  -echo; command ;stty  echo

    See stty(1) manual page for more information.

    For Linux, all I know is that Ubuntu 10.04 (Lucid Lynx) and some Debian/Arch Linux (commented below - thanks, hendry) doesn't have the flusho setting (and I can't see anything other appropriate in the man-page). The echo setting works on the Ubuntu anyway.

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