bg-ampersand - Linux


The “&” character is not a standalone command in Linux, but an operator used within the command line interface to run processes in the background. When appended to a command, it allows the shell to execute the command without blocking further input from the user. This is especially useful for running commands that take a long time to complete or need to continuously operate without user intervention.


The syntax for using the “&” operator is straightforward:

command &

Here, command represents the Linux command you wish to execute. When appended with “&”, the command will execute in the background, allowing you to continue using the terminal for other tasks.


The “&” operator does not have any options or flags. Its sole function is to run the command that precedes it in the background.


  1. Running a simple command in the background:
    Run a Python script in the background:

    python &

    This will start in the background, allowing you to continue working in the same terminal without waiting for the script to complete.

  2. Checking the background process:
    To see a list of all background jobs running in the current shell, use the jobs command:

  3. Managing background processes:
    To bring the most recent background job to the foreground, use:


    If there are multiple jobs, you can specify which one to foreground by job number from the jobs output:

    fg %1

Common Issues

  • Unresponsive Terminal:
    If a background process is still linked to the terminal and starts outputting text, it can interfere with the readability of your terminal. Redirect output to avoid this:

    command > output.txt 2>&1 &
  • Process termination on logout:
    Background processes tied to a terminal session may terminate when you log out. To prevent this, use nohup (no hang up):

    nohup command &


Background tasks often need to be combined with logging or continuous monitoring. Using nohup along with output redirection is a common pattern:

nohup long-running-process > process.out 2>&1 &

This pattern keeps the process running even after logging out and captures all its output into a file for later review.

  • nohup: Ensures a command continues running even after the terminal is closed.
  • jobs: Lists all jobs currently managed by the shell.
  • fg: Brings a background job into the foreground.
  • bg: Resumes suspended jobs in the background.

This overview of the “&” operator should help you effectively manage background processes in your Linux environment, enhancing productivity and system utilization.