Add -device to help text and extend README

README.md

@@ -18,6 +18,11 @@ Common options to all commands:
         -domain <domain|IP>     Network address of device. Mandatory parameter.
         -port <port>            Port the device is reachable on (default 80)
         -password <password>    Connection password (default "reprap")
+        -device <devicename>    This can be used to either create, update (both
+                                in combination with the above options) or load
+                                an already configured device. This makes multi-
+                                device environments easier to handle.
+                                (default "default")
         -verbose                Output more details
         -debug                  Output details on underlying HTTP requests
 
@@ -33,5 +38,27 @@ The commands are:
 
 Use "rfm help <command>" for more information about a command.
 ```
+
+## Configuration File
+`rfm` will create a configuration file in the user's home directory containing connection parameters for all devices (selectable by `-device` options) the user has ever specified.
+This means after connecting succesfully once to a new device this can always be reaccessed by just providing the chosen name to `-device` without the need to reenter `-domain`, `-port` and/or `-password`.
+
+To create or update settings just specify `-device` and the parameters you want to set or update.
+
+### Example
+```
+# Create a new configuration for "first_device". This will be saved in ~/rfm.toml
+rfm ls -device first_device -domain some.domain -port 1234 0:/
+
+# Create a new configuration for "second_device"
+rfm ls -device second_device -domain some.other.domain -port 2345 0:/
+
+# Update configuration of "first_device" after enabling a non-default password
+rfm ls -device first_device -password my_insecure_password 0:/
+
+# Use second_device
+rfm ls -device second_device 0:/
+```
+
 ## Feedback
-Please provide any feedback either here in the Issues or send a pull request or go to [the Duet3D forum](https://forum.duet3d.com/topic/10880/rfm-reprapfirmware-filemanager-duetbackup-successor).
+Please provide any feedback either here in the Issues or send a pull request or go to [the Duet3D forum](https://forum.duet3d.com/topic/10880).

commands/help.go

@@ -20,6 +20,11 @@ Common options to all commands:
         -domain <domain|IP>     Network address of device. Mandatory parameter.
         -port <port>            Port the device is reachable on (default 80)
         -password <password>    Connection password (default "reprap")
+        -device <devicename>    This can be used to either create, update (both
+                                in combination with the above options) or load
+                                an already configured device. This makes multi-
+                                device environments easier to handle.
+                                (default "default")
         -verbose                Output more details
         -debug                  Output details on underlying HTTP requests