github.com/flavio/docker@v0.1.3-0.20170117145210-f63d1a6eec47/docs/reference/commandline/exec.md (about)

     1  ---
     2  title: "exec"
     3  description: "The exec command description and usage"
     4  keywords: "command, container, run, execute"
     5  ---
     6  
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    15  
    16  # exec
    17  
    18  ```markdown
    19  Usage:  docker exec [OPTIONS] CONTAINER COMMAND [ARG...]
    20  
    21  Run a command in a running container
    22  
    23  Options:
    24    -d, --detach         Detached mode: run command in the background
    25        --detach-keys    Override the key sequence for detaching a container
    26    -e, --env=[]         Set environment variables
    27        --help           Print usage
    28    -i, --interactive    Keep STDIN open even if not attached
    29        --privileged     Give extended privileges to the command
    30    -t, --tty            Allocate a pseudo-TTY
    31    -u, --user           Username or UID (format: <name|uid>[:<group|gid>])
    32  ```
    33  
    34  The `docker exec` command runs a new command in a running container.
    35  
    36  The command started using `docker exec` only runs while the container's primary
    37  process (`PID 1`) is running, and it is not restarted if the container is
    38  restarted.
    39  
    40  If the container is paused, then the `docker exec` command will fail with an error:
    41  
    42      $ docker pause test
    43      test
    44      $ docker ps
    45      CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                   PORTS               NAMES
    46      1ae3b36715d2        ubuntu:latest       "bash"              17 seconds ago      Up 16 seconds (Paused)                       test
    47      $ docker exec test ls
    48      FATA[0000] Error response from daemon: Container test is paused, unpause the container before exec
    49      $ echo $?
    50      1
    51  
    52  ## Examples
    53  
    54      $ docker run --name ubuntu_bash --rm -i -t ubuntu bash
    55  
    56  This will create a container named `ubuntu_bash` and start a Bash session.
    57  
    58      $ docker exec -d ubuntu_bash touch /tmp/execWorks
    59  
    60  This will create a new file `/tmp/execWorks` inside the running container
    61  `ubuntu_bash`, in the background.
    62  
    63      $ docker exec -it ubuntu_bash bash
    64  
    65  This will create a new Bash session in the container `ubuntu_bash`.