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@@ -11,3 +11,16 @@ Presently it implements a nearest neighbor one dimensional cellular
 automata and the reversible variants of each rule. The implementation
 is described on
 [richiejp.com/1d-reversible-automata](https://richiejp.com/1d-reversible-automata).
+
+## Command Line
+
+If the command line switch `-f <file path>` is specified then
+`automata` will save an image to `<file path>` and exit. For example:
+
+```sh
+$ ./automata -w 4 -h 256 -i "Shell Example" -f ./210r-256x256.png -r 210 -e
+```
+
+Produces
+
+![Rule 210r](210r-256x256.png)