- [+] update usage doc

Author: suntong

OpenSesame_cli.yaml

@@ -13,7 +13,7 @@ UsageSummary: ""
 
 UsageLead: "\\nUsage:\\n %s [flags..]\\n\\nFlags:\\n\\n"
 
-UsageEnd: "\\n"
+UsageEnd: "\\nWill serve the files from the given path via web server\\nof the given port using a one-time random path.\\n\\nExit and restart will serve from another random path.\\n\\nThe `-port` / `-path` can be overridden by environment variable(s)\\n `OPENSESAME_PORT` / `OPENSESAME_PATH`\\n"
 
 Options:
 
@@ -29,3 +29,8 @@ Options:
     Usage: path to serve files from
     Value: '"./"'
 
+  - Name: Help
+    Type: bool
+    Flag: help
+    Usage: show usage help
+    Value: false

OpenSesame_cliDef.go

@@ -19,6 +19,7 @@ const progname = "OpenSesame" // os.Args[0]
 type Options struct {
 	Port string // listening port
 	Path string // path to serve files from
+	Help bool   // show usage help
 }
 
 ////////////////////////////////////////////////////////////////////////////
@@ -37,6 +38,8 @@ func init() {
 		"listening port")
 	flag.StringVar(&Opts.Path, "path", "./",
 		"path to serve files from")
+	flag.BoolVar(&Opts.Help, "help", false,
+		"show usage help")
 
 	// Now override those default values from environment variables
 	if len(Opts.Port) == 0 ||
@@ -57,6 +60,6 @@ func Usage() {
 		progname)
 	flag.PrintDefaults()
 	fmt.Fprintf(os.Stderr,
-		"\n")
+		"\nWill serve the files from the given path via web server\nof the given port using a one-time random path.\n\nExit and restart will serve from another random path.\n\nThe `-port` / `-path` can be overridden by environment variable(s)\n `OPENSESAME_PORT` / `OPENSESAME_PATH`\n")
 	os.Exit(0)
 }

OpenSesame_main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
 	"math/rand"
@@ -23,6 +24,10 @@ const MaxUint32 = int(^uint32(0))
 
 // Function main
 func main() {
+	flag.Parse()
+	if Opts.Help {
+		Usage()
+	}
 	rand.Seed(time.Now().UTC().UnixNano())
 	app := fiber.New()
 

README.md

@@ -1,2 +1,39 @@
 # OpenSesame
 Open Sesame -- One-time based file sharing
+
+## Usage
+
+```sh
+
+$ OpenSesame -h
+Usage of OpenSesame:
+  -help
+        show usage help
+  -path string
+        path to serve files from (default "./")
+  -port string
+        listening port (default ":18888")
+
+$ OpenSesame -help
+
+Usage:
+ OpenSesame [flags..]
+
+Flags:
+
+  -help
+        show usage help
+  -path string
+        path to serve files from (default "./")
+  -port string
+        listening port (default ":18888")
+
+Will serve the files from the given path via web server
+of the given port using a one-time random path.
+
+Exit and restart will serve from another random path.
+
+The `-port` / `-path` can be overridden by environment variable(s)
+ `OPENSESAME_PORT` / `OPENSESAME_PATH`
+
+```