refactor: file append exercises

17-project-empty-file-finder/exercises/1-sort-to-a-file/main.go

@@ -1,7 +1,7 @@
 package main
 
 // ---------------------------------------------------------
-// EXERCISE: Sort to a file
+// EXERCISE: Sort and write items to a file
 //
 //  1. Get arguments from command-line
 //
@@ -25,17 +25,18 @@ package main
 //
 // HINTS
 //
-//   ONLY READ THIS IF YOU GET STUCK
+//   + REMEMBER: os.Args is a []string
 //
-//   Below, []string means string slice, []byte means byte slice.
+//   + String slices are sortable using `sort.Strings`
 //
-//   + You can use the os.Args[1:] to get a []string
-//   + Then you can sort it using sort.Strings
 //   + Use ioutil.WriteFile to write to a file.
+//
 //   + But you need to convert []string to []byte to be able to
 //     write it to a file using the ioutil.WriteFile.
+//
 //   + To do that, create a new []byte and append the elements of your
 //     []string.
+//
 // ---------------------------------------------------------
 
 func main() {

17-project-empty-file-finder/exercises/2-sort-to-a-file-2/main.go

@@ -8,9 +8,9 @@ import (
 )
 
 // ---------------------------------------------------------
-// EXERCISE: Sort to a file with ordinals
+// EXERCISE: Sort and write items to a file with their ordinals
 //
-//  Use the previous exercise: Append #4
+//  Use the previous exercise.
 //
 //  This time, print the sorted items with ordinals
 //  (see the expected output)
@@ -35,10 +35,10 @@ import (
 //
 //   + You can use strconv.AppendInt function to append an int
 //     to a byte slice. strconv contains a lot of functions for appending
-//     other basic types as well.
+//     other basic types to []byte slices as well.
 //
 //   + You can append individual characters to a byte slice using
-//     rune literals:
+//     rune literals (because: rune literal are typeless numerics):
 //
 //     var slice []byte
 //     slice = append(slice, 'h', 'i', ' ', '!')

17-project-empty-file-finder/exercises/3-print-directories/main.go

@@ -1,7 +1,7 @@
 package main
 
 // ---------------------------------------------------------
-// EXERCISE: Print the directories
+// EXERCISE: Find and write the names of subdirectories to a file
 //
 //  Create a program that can get multiple directory paths from
 //  the command-line, and prints only their subdirectories into a
@@ -43,7 +43,14 @@ package main
 //     (A directory is also a file)
 //
 //   + You can use IsDir method of a FileInfo value to detect
-//     whether a file is a directory or not: go doc os.FileInfo.IsDir
+//     whether a file is a directory or not.
+//
+//     Check out its documentation:
+//
+//     go doc os.FileInfo.IsDir
+//
+//     # or using godocc
+//     godocc os.FileInfo.IsDir
 //
 //   + You can use '\t' escape sequence for indenting the subdirs.
 //