Add more comprehensive help text.

statik.go

@@ -36,22 +36,53 @@ const nameSourceFile = "statik.go"
 var namePackage string
 
 var (
-	flagSrc        = flag.String("src", path.Join(".", "public"), "The path of the source directory.")
-	flagDest       = flag.String("dest", ".", "The destination path of the generated package.")
-	flagNoMtime    = flag.Bool("m", false, "Ignore modification times on files.")
-	flagNoCompress = flag.Bool("Z", false, "Do not use compression to shrink the files.")
-	flagForce      = flag.Bool("f", false, "Overwrite destination file if it already exists.")
-	flagTags       = flag.String("tags", "", "Write build constraint tags")
-	flagPkg        = flag.String("p", "statik", "Name of the generated package")
-	flagPkgCmt     = flag.String("c", "Package statik contains static assets.", "The package comment. An empty value disables this comment.\n")
-	flagInclude    = flag.String("include", "*.*", "The patterns of files to be included (by comma separated).\n")
+	flagSrc        = flag.String("src", path.Join(".", "public"), "")
+	flagDest       = flag.String("dest", ".", "")
+	flagNoMtime    = flag.Bool("m", false, "")
+	flagNoCompress = flag.Bool("Z", false, "")
+	flagForce      = flag.Bool("f", false, "")
+	flagTags       = flag.String("tags", "", "")
+	flagPkg        = flag.String("p", "statik", "")
+	flagPkgCmt     = flag.String("c", "", "")
+	flagInclude    = flag.String("include", "*.*", "")
 )
 
+const helpText = `statik [options]
+
+Options:
+-src     The source directory of the assets. "public" by default.
+-dest    The destination directory of the generated package. "." by default.
+
+-f       Override destination if it already exists, false by default.
+-include Wildcard to filter files to include, "*.*" by default.
+-m       Ignore modification times on files, false by default.
+-Z       Do not use compression, false by default.
+
+-p       Name of the generated package, "statik" by default.
+-tags    Build tags for the generated package.
+-c       Godoc for the generated package.
+
+-help    Prints this text.
+
+Examples:
+
+Generates a statik package from ./assets directory. Overrides
+if there is already an existing package.
+
+   $ statik -src=assets -f
+
+Generates a statik package only with the ".js" files
+from the ./public directory.
+
+   $ statik -include=*.js
+`
+
 // mtimeDate holds the arbitrary mtime that we assign to files when
 // flagNoMtime is set.
 var mtimeDate = time.Date(2000, time.January, 1, 0, 0, 0, 0, time.UTC)
 
 func main() {
+	flag.Usage = help
 	flag.Parse()
 
 	namePackage = *flagPkg
@@ -286,3 +317,8 @@ func exitWithError(err error) {
 	fmt.Println(err)
 	os.Exit(1)
 }
+
+func help() {
+	fmt.Println(helpText)
+	os.Exit(1)
+}