publish command-line-arguments and command-line-flags

examples/command-line-arguments/command-line-arguments.go

@@ -1,23 +1,26 @@
-// Use `os.Args` to access command-line arguments and
-// the name of the program.
+// [_Command-line arguments_](http://en.wikipedia.org/wiki/Command-line_interface#Arguments)
+// are a common way to parameterize execution of programs.
+// For example, `go run hello.go` uses `run` and
+// `hello.go` arguments to the `go` program.
+
 package main
 
 import "os"
 import "fmt"
 
 func main() {
-    // `os.Args` includes the program name as the first
-    // value.
+
+    // `os.Args` provides access to raw command-line
+    // arguments. Note that the first value in this slice
+    // is the path to the program, and `os.Args[1:]`
+    // holds the arguments to the program.
     argsWithProg := os.Args
     argsWithoutProg := os.Args[1:]
 
-    // `Args` are a slice, you can get individual args
-    // with normal indexing.
+    // You can get individual args with normal indexing.
     arg := os.Args[3]
 
     fmt.Println(argsWithProg)
     fmt.Println(argsWithoutProg)
     fmt.Println(arg)
 }
-
-// todo: discuss building before here

examples/command-line-arguments/command-line-arguments.sh

@@ -1,9 +1,10 @@
-# Build a `command-line-args` binary so that we have
-# the expected program name.
-$ go build command-line-arguments      
-                                    
-
+# To experiment with command-line arguments it's best to
+# build a binary with `go build` first.
+$ go build command-line-arguments.go
 $ ./command-line-arguments a b c d
-[command-line-arguments a b c d]       
+[./command-line-arguments a b c d]       
 [a b c d]
 c
+
+# Next we'll look at more advanced command-line processing
+# with flags.