Merge pull request #172 from skx/no-embed

Allow hiding the embedded binaries

README.md

@@ -154,6 +154,8 @@ There are many available command-line options, which are shown in the output of
   * Change to the given directory before running.
 * `-directories`
   * Use directories on the host for drive-contents, discussed later in this document.
+* `-embed`
+  * Enable/Disable the embedded binaries we unconditionally add to the A:-drive.  (The utilities to change the output driver, toggle debugging, etc.)
 * `-log-path /path/to/file`
   * Output debug-logs to the given file, creating it if necessary.
   * **NOTE**: You can run `A:!DEBUG 1` to enable "quick debug logging", and `A:!DEBUG 0` to turn it back off again, at runtime.
@@ -183,7 +185,7 @@ This allows you to customize the emulator, or perform other "one-time" setup via
 
 There are a small number of [extensions](EXTENSIONS.md) added to the BIOS functionality we provide, and these extensions allow changing some aspects of the emulator at runtime.
 
-The behaviour changing is achieved by having a small number of .COM files invoke the extension functions, and these binaries are embedded within our emulator to improve ease of use, via the [static/](static/) directory in our source-tree.  This means no matter what you'll always find some binaries installed on A:, despite not being present in reality.
+The behaviour changing is achieved by having a small number of .COM files invoke the extension functions, and these binaries are embedded within our emulator to improve ease of use, via the [static/](static/) directory in our source-tree.  This means no matter what you'll always find some binaries installed on A:, despite not being present in reality - you can disable the appearance of these binaries via the `-embed=false` command-line flag.
 
 > **NOTE** To avoid naming collisions all our embedded binaries are named with a `!` prefix, except for `#.COM` which is designed to be used as a comment-binary.
 

main.go

@@ -56,6 +56,7 @@ func main() {
 	ccp := flag.String("ccp", "ccpz", "The name of the CCP that we should run (ccp vs. ccpz).")
 	cd := flag.String("cd", "", "Change to this directory before launching")
 	createDirectories := flag.Bool("create", false, "Create subdirectories on the host computer for each CP/M drive.")
+	embedBin := flag.Bool("embed", true, "Should we embed our utility commands into the A: filesystem.")
 	input := flag.String("input", cpm.DefaultInputDriver, "The name of the console input driver to use (-list-input-drivers will show valid choices).")
 	output := flag.String("output", cpm.DefaultOutputDriver, "The name of the console output driver to use (-list-output-drivers will show valid choices).")
 	logAll := flag.Bool("log-all", false, "Log all function invocations, including the noisy console I/O ones.")
@@ -269,7 +270,11 @@ func main() {
 	}
 
 	// Load any embedded files within our binary
-	obj.SetStaticFilesystem(static.GetContent())
+	if *embedBin {
+		obj.SetStaticFilesystem(static.GetContent())
+	} else {
+		obj.SetStaticFilesystem(static.GetEmptyContent())
+	}
 
 	// Default to not using subdirectories for drives
 	obj.SetDrives(false)

static/static.go

@@ -10,7 +10,15 @@ import "embed"
 //go:embed */*
 var content embed.FS
 
+// empty has no contents.
+var empty embed.FS
+
 // GetContent returns the embedded filesystem we store within this package.
 func GetContent() embed.FS {
 	return content
 }
+
+// GetEmptyContent returns the embedded filesystem we store within this package which has no contents.
+func GetEmptyContent() embed.FS {
+	return empty
+}

static/static_test.go

@@ -22,3 +22,17 @@ func TestStatic(t *testing.T) {
 		}
 	}
 }
+
+// TestEmpty ensures we have no files.
+func TestEmpty(t *testing.T) {
+
+	// Read the subdirectory
+	files, err := GetEmptyContent().ReadDir(".")
+	if err != nil {
+		t.Fatalf("error reading contents")
+	}
+
+	if len(files) != 0 {
+		t.Fatalf("got files, but expected none")
+	}
+}