How to Redirect stdout and stderr to File in Bash

In Bash scripting, stdout (standard output) and stderr (standard error) can be redirected to a file for logging and debugging purposes. This guide enlightens different ways to redirect stdout and stderr in Bash.

Follow these steps:

1. Redirect stdout to a File:
   1. To redirect standard output to a file, use the > operator:

      command > output.txt

      This will overwrite output.txt with the command’s output.

   2. To append output instead of overwriting, use >>:

      command >> output.txt

2. Redirect stderr to a File:
   1. To redirect only stderr to a file, use 2>:

      command 2> error.txt

   2. To append stderr to a file, use 2>>:

      command 2>> error.txt

3. Redirect stdout and stderr to the Same File:
   1. To redirect both stdout and stderr to the same file, use &>:

      command &> output.txt

   2. To append both outputs to a file, use:

      command &>> output.txt

4. Redirect stdout and stderr separately:
   1. You can redirect stdout and stderr to different files:

      command > output.txt 2> error.txt

5. Redirect stdout to a File and stderr to stdout:
   1. To send stderr to the same location as stdout, use:

      command > output.txt 2>&1

      This ensures that both stdout and stderr are stored in output.txt.

6. Redirect stdout and stderr to /dev/null:
   1. To discard both stdout and stderr (suppress output), redirect them to /dev/null:

      command > /dev/null 2>&1

      This is useful when you don’t want to see any output from the command.

Redirecting stdout and stderr in Bash helps manage output efficiently, allowing for better logging, debugging, and automation. Use these redirection techniques as per your requirements to handle command outputs effectively.

Learn more on How to Redirect your Root Directory to a Subdirectory.