docs: improve formatting and highlighting of docker ps reference

this improves the formatting, and code-highlighting
of the `docker ps` reference page, and wraps sentences
to 80 chars

also adds single quotes around the formatting
example for labels.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 07ef0a37f85fbb3ba0be4a09bb301108bf461d96)
Signed-off-by: Tibor Vass <tibor@docker.com>

docs/reference/commandline/ps.md

@@ -38,15 +38,24 @@ Options:
 
 Running `docker ps --no-trunc` showing 2 linked containers.
 
-    $ docker ps
-    CONTAINER ID        IMAGE                        COMMAND                CREATED              STATUS              PORTS               NAMES
-    4c01db0b339c        ubuntu:12.04                 bash                   17 seconds ago       Up 16 seconds       3300-3310/tcp       webapp
-    d7886598dbe2        crosbymichael/redis:latest   /redis-server --dir    33 minutes ago       Up 33 minutes       6379/tcp            redis,webapp/db
+```bash
+$ docker ps
+
+CONTAINER ID        IMAGE                        COMMAND                CREATED              STATUS              PORTS               NAMES
+4c01db0b339c        ubuntu:12.04                 bash                   17 seconds ago       Up 16 seconds       3300-3310/tcp       webapp
+d7886598dbe2        crosbymichael/redis:latest   /redis-server --dir    33 minutes ago       Up 33 minutes       6379/tcp            redis,webapp/db
+```
+
+The `docker ps` command only shows running containers by default. To see all
+containers, use the `-a` (or `--all`) flag:
 
-`docker ps` will show only running containers by default. To see all containers:
-`docker ps -a`
+```bash
+$ docker ps -a
+```
 
-`docker ps` will group exposed ports into a single range if possible. E.g., a container that exposes TCP ports `100, 101, 102` will display `100-102/tcp` in the `PORTS` column.
+`docker ps` groups exposed ports into a single range if possible. E.g., a
+container that exposes TCP ports `100, 101, 102` displays `100-102/tcp` in
+the `PORTS` column.
 
 ## Filtering
 
@@ -74,16 +83,22 @@ value.
 
 The following filter matches containers with the `color` label regardless of its value.
 
-    $ docker ps --filter "label=color"
-    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
-    673394ef1d4c        busybox             "top"               47 seconds ago      Up 45 seconds                           nostalgic_shockley
-    d85756f57265        busybox             "top"               52 seconds ago      Up 51 seconds                           high_albattani
+```bash
+$ docker ps --filter "label=color"
+
+CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
+673394ef1d4c        busybox             "top"               47 seconds ago      Up 45 seconds                           nostalgic_shockley
+d85756f57265        busybox             "top"               52 seconds ago      Up 51 seconds                           high_albattani
+```
 
 The following filter matches containers with the `color` label with the `blue` value.
 
-    $ docker ps --filter "label=color=blue"
-    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
-    d85756f57265        busybox             "top"               About a minute ago   Up About a minute                       high_albattani
+```bash
+$ docker ps --filter "label=color=blue"
+
+CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
+d85756f57265        busybox             "top"               About a minute ago   Up About a minute                       high_albattani
+```
 
 #### Name
 
@@ -91,49 +106,66 @@ The `name` filter matches on all or part of a container's name.
 
 The following filter matches all containers with a name containing the `nostalgic_stallman` string.
 
-    $ docker ps --filter "name=nostalgic_stallman"
-    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
-    9b6247364a03        busybox             "top"               2 minutes ago       Up 2 minutes                            nostalgic_stallman
+```bash
+$ docker ps --filter "name=nostalgic_stallman"
+
+CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
+9b6247364a03        busybox             "top"               2 minutes ago       Up 2 minutes                            nostalgic_stallman
+```
 
 You can also filter for a substring in a name as this shows:
 
-    $ docker ps --filter "name=nostalgic"
-    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
-    715ebfcee040        busybox             "top"               3 seconds ago       Up 1 seconds                            i_am_nostalgic
-    9b6247364a03        busybox             "top"               7 minutes ago       Up 7 minutes                            nostalgic_stallman
-    673394ef1d4c        busybox             "top"               38 minutes ago      Up 38 minutes                           nostalgic_shockley
+```bash
+$ docker ps --filter "name=nostalgic"
+
+CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
+715ebfcee040        busybox             "top"               3 seconds ago       Up 1 seconds                            i_am_nostalgic
+9b6247364a03        busybox             "top"               7 minutes ago       Up 7 minutes                            nostalgic_stallman
+673394ef1d4c        busybox             "top"               38 minutes ago      Up 38 minutes                           nostalgic_shockley
+```
 
 #### Exited
 
-The `exited` filter matches containers by exist status code. For example, to filter for containers
-that have exited successfully:
+The `exited` filter matches containers by exist status code. For example, to
+filter for containers that have exited successfully:
+
+```bash
+$ docker ps -a --filter 'exited=0'
 
-    $ docker ps -a --filter 'exited=0'
-    CONTAINER ID        IMAGE             COMMAND                CREATED             STATUS                   PORTS                      NAMES
-    ea09c3c82f6e        registry:latest   /srv/run.sh            2 weeks ago         Exited (0) 2 weeks ago   127.0.0.1:5000->5000/tcp   desperate_leakey
-    106ea823fe4e        fedora:latest     /bin/sh -c 'bash -l'   2 weeks ago         Exited (0) 2 weeks ago                              determined_albattani
-    48ee228c9464        fedora:20         bash                   2 weeks ago         Exited (0) 2 weeks ago                              tender_torvalds
+CONTAINER ID        IMAGE             COMMAND                CREATED             STATUS                   PORTS                      NAMES
+ea09c3c82f6e        registry:latest   /srv/run.sh            2 weeks ago         Exited (0) 2 weeks ago   127.0.0.1:5000->5000/tcp   desperate_leakey
+106ea823fe4e        fedora:latest     /bin/sh -c 'bash -l'   2 weeks ago         Exited (0) 2 weeks ago                              determined_albattani
+48ee228c9464        fedora:20         bash                   2 weeks ago         Exited (0) 2 weeks ago                              tender_torvalds
+```
 
 #### Status
 
-The `status` filter matches containers by status. You can filter using `created`, `restarting`, `running`, `paused`, `exited` and `dead`. For example, to filter for `running` containers:
+The `status` filter matches containers by status. You can filter using
+`created`, `restarting`, `running`, `paused`, `exited` and `dead`. For example,
+to filter for `running` containers:
+
+```bash
+$ docker ps --filter status=running
 
-    $ docker ps --filter status=running
-    CONTAINER ID        IMAGE                  COMMAND             CREATED             STATUS              PORTS               NAMES
-    715ebfcee040        busybox                "top"               16 minutes ago      Up 16 minutes                           i_am_nostalgic
-    d5c976d3c462        busybox                "top"               23 minutes ago      Up 23 minutes                           top
-    9b6247364a03        busybox                "top"               24 minutes ago      Up 24 minutes                           nostalgic_stallman
+CONTAINER ID        IMAGE                  COMMAND             CREATED             STATUS              PORTS               NAMES
+715ebfcee040        busybox                "top"               16 minutes ago      Up 16 minutes                           i_am_nostalgic
+d5c976d3c462        busybox                "top"               23 minutes ago      Up 23 minutes                           top
+9b6247364a03        busybox                "top"               24 minutes ago      Up 24 minutes                           nostalgic_stallman
+```
 
 To filter for `paused` containers:
 
-    $ docker ps --filter status=paused
-    CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
-    673394ef1d4c        busybox             "top"               About an hour ago   Up About an hour (Paused)                       nostalgic_shockley
+```bash
+$ docker ps --filter status=paused
+
+CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
+673394ef1d4c        busybox             "top"               About an hour ago   Up About an hour (Paused)                       nostalgic_shockley
+```
 
 #### Ancestor
 
-The `ancestor` filter matches containers based on its image or a descendant of it. The filter supports the
-following image representation:
+The `ancestor` filter matches containers based on its image or a descendant of
+it. The filter supports the following image representation:
 
 - image
 - image:tag
@@ -141,74 +173,99 @@ following image representation:
 - short-id
 - full-id
 
-If you don't specify a `tag`, the `latest` tag is used. For example, to filter for containers that use the
-latest `ubuntu` image:
+If you don't specify a `tag`, the `latest` tag is used. For example, to filter
+for containers that use the latest `ubuntu` image:
+
+```bash
+$ docker ps --filter ancestor=ubuntu
 
-    $ docker ps --filter ancestor=ubuntu
-    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
-    919e1179bdb8        ubuntu-c1           "top"               About a minute ago   Up About a minute                       admiring_lovelace
-    5d1e4a540723        ubuntu-c2           "top"               About a minute ago   Up About a minute                       admiring_sammet
-    82a598284012        ubuntu              "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
-    bab2a34ba363        ubuntu              "top"               3 minutes ago        Up 3 minutes                            focused_yonath
+CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
+919e1179bdb8        ubuntu-c1           "top"               About a minute ago   Up About a minute                       admiring_lovelace
+5d1e4a540723        ubuntu-c2           "top"               About a minute ago   Up About a minute                       admiring_sammet
+82a598284012        ubuntu              "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
+bab2a34ba363        ubuntu              "top"               3 minutes ago        Up 3 minutes                            focused_yonath
+```
 
-Match containers based on the `ubuntu-c1` image which, in this case, is a child of `ubuntu`:
+Match containers based on the `ubuntu-c1` image which, in this case, is a child
+of `ubuntu`:
 
-    $ docker ps --filter ancestor=ubuntu-c1
-    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
-    919e1179bdb8        ubuntu-c1           "top"               About a minute ago   Up About a minute                       admiring_lovelace
+```bash
+$ docker ps --filter ancestor=ubuntu-c1
+
+CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
+919e1179bdb8        ubuntu-c1           "top"               About a minute ago   Up About a minute                       admiring_lovelace
+```
 
 Match containers based on the `ubuntu` version `12.04.5` image:
 
-    $ docker ps --filter ancestor=ubuntu:12.04.5
-    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
-    82a598284012        ubuntu:12.04.5      "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
+```bash
+$ docker ps --filter ancestor=ubuntu:12.04.5
+
+CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
+82a598284012        ubuntu:12.04.5      "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
+```
+
+The following matches containers based on the layer `d0e008c6cf02` or an image
+that have this layer in it's layer stack.
 
-The following matches containers based on the layer `d0e008c6cf02` or an image that have this layer
-in it's layer stack.
+```bash
+$ docker ps --filter ancestor=d0e008c6cf02
 
-    $ docker ps --filter ancestor=d0e008c6cf02
-    CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
-    82a598284012        ubuntu:12.04.5      "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
+CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS              PORTS               NAMES
+82a598284012        ubuntu:12.04.5      "top"               3 minutes ago        Up 3 minutes                            sleepy_bose
+```
 
 #### Before
 
-The `before` filter shows only containers created before the container with given id or name. For example, 
-having these containers created:
+The `before` filter shows only containers created before the container with
+given id or name. For example, having these containers created:
+
+```bash
+$ docker ps
 
-    $ docker ps
-    CONTAINER ID        IMAGE       COMMAND       CREATED              STATUS              PORTS              NAMES
-    9c3527ed70ce        busybox     "top"         14 seconds ago       Up 15 seconds                          desperate_dubinsky
-    4aace5031105        busybox     "top"         48 seconds ago       Up 49 seconds                          focused_hamilton
-    6e63f6ff38b0        busybox     "top"         About a minute ago   Up About a minute                      distracted_fermat
+CONTAINER ID        IMAGE       COMMAND       CREATED              STATUS              PORTS              NAMES
+9c3527ed70ce        busybox     "top"         14 seconds ago       Up 15 seconds                          desperate_dubinsky
+4aace5031105        busybox     "top"         48 seconds ago       Up 49 seconds                          focused_hamilton
+6e63f6ff38b0        busybox     "top"         About a minute ago   Up About a minute                      distracted_fermat
+```
 
 Filtering with `before` would give:
 
-    $ docker ps -f before=9c3527ed70ce
-    CONTAINER ID        IMAGE       COMMAND       CREATED              STATUS              PORTS              NAMES
-    4aace5031105        busybox     "top"         About a minute ago   Up About a minute                      focused_hamilton
-    6e63f6ff38b0        busybox     "top"         About a minute ago   Up About a minute                      distracted_fermat
+```bash
+$ docker ps -f before=9c3527ed70ce
+
+CONTAINER ID        IMAGE       COMMAND       CREATED              STATUS              PORTS              NAMES
+4aace5031105        busybox     "top"         About a minute ago   Up About a minute                      focused_hamilton
+6e63f6ff38b0        busybox     "top"         About a minute ago   Up About a minute                      distracted_fermat
+```
 
 #### Since
 
-The `since` filter shows only containers created since the container with given id or name. For example,
-with the same containers as in `before` filter:
+The `since` filter shows only containers created since the container with given
+id or name. For example, with the same containers as in `before` filter:
 
-    $ docker ps -f since=6e63f6ff38b0
-    CONTAINER ID        IMAGE       COMMAND       CREATED             STATUS              PORTS               NAMES
-    9c3527ed70ce        busybox     "top"         10 minutes ago      Up 10 minutes                           desperate_dubinsky
-    4aace5031105        busybox     "top"         10 minutes ago      Up 10 minutes                           focused_hamilton
+```bash
+$ docker ps -f since=6e63f6ff38b0
+
+CONTAINER ID        IMAGE       COMMAND       CREATED             STATUS              PORTS               NAMES
+9c3527ed70ce        busybox     "top"         10 minutes ago      Up 10 minutes                           desperate_dubinsky
+4aace5031105        busybox     "top"         10 minutes ago      Up 10 minutes                           focused_hamilton
+```
 
 #### Volume
 
-The `volume` filter shows only containers that mount a specific volume or have a volume mounted in a specific path:
+The `volume` filter shows only containers that mount a specific volume or have
+a volume mounted in a specific path:
 
-    $ docker ps --filter volume=remote-volume --format "table {{.ID}}\t{{.Mounts}}"
-    CONTAINER ID        MOUNTS
-    9c3527ed70ce        remote-volume
+```bash
+$ docker ps --filter volume=remote-volume --format "table {{.ID}}\t{{.Mounts}}"
+CONTAINER ID        MOUNTS
+9c3527ed70ce        remote-volume
 
-    $ docker ps --filter volume=/data --format "table {{.ID}}\t{{.Mounts}}"
-    CONTAINER ID        MOUNTS
-    9c3527ed70ce        remote-volume
+$ docker ps --filter volume=/data --format "table {{.ID}}\t{{.Mounts}}"
+CONTAINER ID        MOUNTS
+9c3527ed70ce        remote-volume
+```
 
 #### Network
 
@@ -223,6 +280,7 @@ $ docker run -d --net=net1 --name=test1 ubuntu top
 $ docker run -d --net=net2 --name=test2 ubuntu top
 
 $ docker ps --filter network=net1
+
 CONTAINER ID        IMAGE       COMMAND       CREATED             STATUS              PORTS               NAMES
 9d4893ed80fe        ubuntu      "top"         10 minutes ago      Up 10 minutes                           test1
 ```
@@ -233,51 +291,61 @@ the network id as a filter;
 
 ```bash
 $ docker network inspect --format "{{.ID}}" net1
+
 8c0b4110ae930dbe26b258de9bc34a03f98056ed6f27f991d32919bfe401d7c5
 
 $ docker ps --filter network=8c0b4110ae930dbe26b258de9bc34a03f98056ed6f27f991d32919bfe401d7c5
+
 CONTAINER ID        IMAGE       COMMAND       CREATED             STATUS              PORTS               NAMES
 9d4893ed80fe        ubuntu      "top"         10 minutes ago      Up 10 minutes                           test1
 ```
 
 ## Formatting
 
-The formatting option (`--format`) will pretty-print container output using a Go template.
+The formatting option (`--format`) pretty-prints container output using a Go
+template.
 
 Valid placeholders for the Go template are listed below:
 
-Placeholder | Description
----- | ----
-`.ID` | Container ID
-`.Image` | Image ID
-`.Command` | Quoted command
-`.CreatedAt` | Time when the container was created.
+Placeholder   | Description
+--------------|----------------------------------------------------------------------------------------------------
+`.ID`         | Container ID
+`.Image`      | Image ID
+`.Command`    | Quoted command
+`.CreatedAt`  | Time when the container was created.
 `.RunningFor` | Elapsed time since the container was started.
-`.Ports` | Exposed ports.
-`.Status` | Container status.
-`.Size` | Container disk size.
-`.Names` | Container names.
-`.Labels` | All labels assigned to the container.
-`.Label` | Value of a specific label for this container. For example `{{.Label "com.docker.swarm.cpu"}}`
-`.Mounts` | Names of the volumes mounted in this container.
-
-When using the `--format` option, the `ps` command will either output the data exactly as the template
-declares or, when using the `table` directive, will include column headers as well.
-
-The following example uses a template without headers and outputs the `ID` and `Command`
-entries separated by a colon for all running containers:
-
-    $ docker ps --format "{{.ID}}: {{.Command}}"
-    a87ecb4f327c: /bin/sh -c #(nop) MA
-    01946d9d34d8: /bin/sh -c #(nop) MA
-    c1d3b0166030: /bin/sh -c yum -y up
-    41d50ecd2f57: /bin/sh -c #(nop) MA
+`.Ports`      | Exposed ports.
+`.Status`     | Container status.
+`.Size`       | Container disk size.
+`.Names`      | Container names.
+`.Labels`     | All labels assigned to the container.
+`.Label`      | Value of a specific label for this container. For example `'{{.Label "com.docker.swarm.cpu"}}'`
+`.Mounts`     | Names of the volumes mounted in this container.
+
+When using the `--format` option, the `ps` command will either output the data
+exactly as the template declares or, when using the `table` directive, includes
+column headers as well.
+
+The following example uses a template without headers and outputs the `ID` and
+`Command` entries separated by a colon for all running containers:
+
+```bash
+$ docker ps --format "{{.ID}}: {{.Command}}"
+
+a87ecb4f327c: /bin/sh -c #(nop) MA
+01946d9d34d8: /bin/sh -c #(nop) MA
+c1d3b0166030: /bin/sh -c yum -y up
+41d50ecd2f57: /bin/sh -c #(nop) MA
+```
 
 To list all running containers with their labels in a table format you can use:
 
-    $ docker ps --format "table {{.ID}}\t{{.Labels}}"
-    CONTAINER ID        LABELS
-    a87ecb4f327c        com.docker.swarm.node=ubuntu,com.docker.swarm.storage=ssd
-    01946d9d34d8
-    c1d3b0166030        com.docker.swarm.node=debian,com.docker.swarm.cpu=6
-    41d50ecd2f57        com.docker.swarm.node=fedora,com.docker.swarm.cpu=3,com.docker.swarm.storage=ssd
+```bash
+$ docker ps --format "table {{.ID}}\t{{.Labels}}"
+
+CONTAINER ID        LABELS
+a87ecb4f327c        com.docker.swarm.node=ubuntu,com.docker.swarm.storage=ssd
+01946d9d34d8
+c1d3b0166030        com.docker.swarm.node=debian,com.docker.swarm.cpu=6
+41d50ecd2f57        com.docker.swarm.node=fedora,com.docker.swarm.cpu=3,com.docker.swarm.storage=ssd
+```