diff --git a/examples.txt b/examples.txt
index 91a1fde..887ef69 100644
--- a/examples.txt
+++ b/examples.txt
@@ -58,6 +58,7 @@ Reading Files
Writing Files
Line Filters
File Paths
+Directories
Command-Line Arguments
Command-Line Flags
Command-Line Subcommands
diff --git a/examples/directories/directories.go b/examples/directories/directories.go
new file mode 100644
index 0000000..9b71274
--- /dev/null
+++ b/examples/directories/directories.go
@@ -0,0 +1,95 @@
+// Go has several useful functions for working with
+// *directories* in the file system.
+
+package main
+
+import (
+ "fmt"
+ "io/ioutil"
+ "os"
+ "path/filepath"
+)
+
+func check(e error) {
+ if e != nil {
+ panic(e)
+ }
+}
+
+func main() {
+
+ // Create a new sub-directory in the current working
+ // directory.
+ err := os.Mkdir("subdir", 0755)
+ check(err)
+
+ // When creating temporary directories, it's good
+ // practice to `defer` their removal. `os.RemoveAll`
+ // will delete a whole directory tree (similarly to
+ // `rm -rf`).
+ defer os.RemoveAll("subdir")
+
+ // Helper function to create a new empty file.
+ createEmptyFile := func(name string) {
+ d := []byte("")
+ check(ioutil.WriteFile(name, d, 0644))
+ }
+
+ createEmptyFile("subdir/file1")
+
+ // We can create a hierarchy of directories, including
+ // parents with `MkdirAll`. This is similar to the
+ // command-line `mkdir -p`.
+ err = os.MkdirAll("subdir/parent/child", 0755)
+ check(err)
+
+ createEmptyFile("subdir/parent/file2")
+ createEmptyFile("subdir/parent/file3")
+ createEmptyFile("subdir/parent/child/file4")
+
+ // `ReadDir` lists directory contents, returning a
+ // slice of `os.FileInfo` objects.
+ c, err := ioutil.ReadDir("subdir/parent")
+ check(err)
+
+ fmt.Println("Listing subdir/parent")
+ for _, entry := range c {
+ fmt.Println(" ", entry.Name(), entry.IsDir())
+ }
+
+ // `Chdir` lets us change the current working directory,
+ // similarly to `cd`.
+ err = os.Chdir("subdir/parent/child")
+ check(err)
+
+ // Now we'll see the contents of `subdir/parent/child`
+ // when listing the *current* directory.
+ c, err = ioutil.ReadDir(".")
+ check(err)
+
+ fmt.Println("Listing subdir/parent/child")
+ for _, entry := range c {
+ fmt.Println(" ", entry.Name(), entry.IsDir())
+ }
+
+ // `cd` back to where we started.
+ err = os.Chdir("../../..")
+ check(err)
+
+ // We can also visit a directory *recursively*,
+ // including all its sub-directories. `Walk` accepts
+ // a callback function to handle every file or
+ // directory visited.
+ fmt.Println("Visiting subdir")
+ err = filepath.Walk("subdir", visit)
+}
+
+// `visit` is called for every file or directory found
+// recursively by `filepath.Walk`.
+func visit(p string, info os.FileInfo, err error) error {
+ if err != nil {
+ return err
+ }
+ fmt.Println(" ", p, info.IsDir())
+ return nil
+}
diff --git a/examples/directories/directories.hash b/examples/directories/directories.hash
new file mode 100644
index 0000000..cebae56
--- /dev/null
+++ b/examples/directories/directories.hash
@@ -0,0 +1,2 @@
+83f67db91816b4544072d0a4d099111a21c60723
+-7kWq0PmATF
diff --git a/examples/directories/directories.sh b/examples/directories/directories.sh
new file mode 100644
index 0000000..31a8f0c
--- /dev/null
+++ b/examples/directories/directories.sh
@@ -0,0 +1,15 @@
+$ go run directories.go
+Listing subdir/parent
+ child true
+ file2 false
+ file3 false
+Listing subdir/parent/child
+ file4 false
+Visiting subdir
+ subdir true
+ subdir/file1 false
+ subdir/parent true
+ subdir/parent/child true
+ subdir/parent/child/file4 false
+ subdir/parent/file2 false
+ subdir/parent/file3 false
diff --git a/public/directories b/public/directories
new file mode 100644
index 0000000..e0746ba
--- /dev/null
+++ b/public/directories
@@ -0,0 +1,343 @@
+<!DOCTYPE html>
+<html>
+ <head>
+ <meta charset="utf-8">
+ <title>Go by Example: Directories</title>
+ <link rel=stylesheet href="site.css">
+ </head>
+ <body>
+ <div class="example" id="directories">
+ <h2><a href="./">Go by Example</a>: Directories</h2>
+
+ <table>
+
+ <tr>
+ <td class="docs">
+ <p>Go has several useful functions for working with
+<em>directories</em> in the file system.</p>
+
+ </td>
+ <td class="code empty leading">
+
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+ <a href="http://play.golang.org/p/-7kWq0PmATF">
+ <img title="Run code" class="run" src="data:image/png;base64,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" />
+ </a>
+ <div class="highlight"><pre><span class="kn">package</span> <span class="nx">main</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre><span class="kn">import</span> <span class="p">(</span>
+ <span class="s">"fmt"</span>
+ <span class="s">"io/ioutil"</span>
+ <span class="s">"os"</span>
+ <span class="s">"path/filepath"</span>
+<span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre><span class="kd">func</span> <span class="nx">check</span><span class="p">(</span><span class="nx">e</span> <span class="kt">error</span><span class="p">)</span> <span class="p">{</span>
+ <span class="k">if</span> <span class="nx">e</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
+ <span class="nb">panic</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span>
+ <span class="p">}</span>
+<span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre><span class="kd">func</span> <span class="nx">main</span><span class="p">()</span> <span class="p">{</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>Create a new sub-directory in the current working
+directory.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">os</span><span class="p">.</span><span class="nx">Mkdir</span><span class="p">(</span><span class="s">"subdir"</span><span class="p">,</span> <span class="mo">0755</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>When creating temporary directories, it’s good
+practice to <code>defer</code> their removal. <code>os.RemoveAll</code>
+will delete a whole directory tree (similarly to
+<code>rm -rf</code>).</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="k">defer</span> <span class="nx">os</span><span class="p">.</span><span class="nx">RemoveAll</span><span class="p">(</span><span class="s">"subdir"</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>Helper function to create a new empty file.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">createEmptyFile</span> <span class="o">:=</span> <span class="kd">func</span><span class="p">(</span><span class="nx">name</span> <span class="kt">string</span><span class="p">)</span> <span class="p">{</span>
+ <span class="nx">d</span> <span class="o">:=</span> <span class="p">[]</span><span class="nb">byte</span><span class="p">(</span><span class="s">""</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">ioutil</span><span class="p">.</span><span class="nx">WriteFile</span><span class="p">(</span><span class="nx">name</span><span class="p">,</span> <span class="nx">d</span><span class="p">,</span> <span class="mo">0644</span><span class="p">))</span>
+ <span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">createEmptyFile</span><span class="p">(</span><span class="s">"subdir/file1"</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>We can create a hierarchy of directories, including
+parents with <code>MkdirAll</code>. This is similar to the
+command-line <code>mkdir -p</code>.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">err</span> <span class="p">=</span> <span class="nx">os</span><span class="p">.</span><span class="nx">MkdirAll</span><span class="p">(</span><span class="s">"subdir/parent/child"</span><span class="p">,</span> <span class="mo">0755</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">createEmptyFile</span><span class="p">(</span><span class="s">"subdir/parent/file2"</span><span class="p">)</span>
+ <span class="nx">createEmptyFile</span><span class="p">(</span><span class="s">"subdir/parent/file3"</span><span class="p">)</span>
+ <span class="nx">createEmptyFile</span><span class="p">(</span><span class="s">"subdir/parent/child/file4"</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p><code>ReadDir</code> lists directory contents, returning a
+slice of <code>os.FileInfo</code> objects.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">c</span><span class="p">,</span> <span class="nx">err</span> <span class="o">:=</span> <span class="nx">ioutil</span><span class="p">.</span><span class="nx">ReadDir</span><span class="p">(</span><span class="s">"subdir/parent"</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"Listing subdir/parent"</span><span class="p">)</span>
+ <span class="k">for</span> <span class="nx">_</span><span class="p">,</span> <span class="nx">entry</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">c</span> <span class="p">{</span>
+ <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" "</span><span class="p">,</span> <span class="nx">entry</span><span class="p">.</span><span class="nx">Name</span><span class="p">(),</span> <span class="nx">entry</span><span class="p">.</span><span class="nx">IsDir</span><span class="p">())</span>
+ <span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p><code>Chdir</code> lets us change the current working directory,
+similarly to <code>cd</code>.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">err</span> <span class="p">=</span> <span class="nx">os</span><span class="p">.</span><span class="nx">Chdir</span><span class="p">(</span><span class="s">"subdir/parent/child"</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>Now we’ll see the contents of <code>subdir/parent/child</code>
+when listing the <em>current</em> directory.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">c</span><span class="p">,</span> <span class="nx">err</span> <span class="p">=</span> <span class="nx">ioutil</span><span class="p">.</span><span class="nx">ReadDir</span><span class="p">(</span><span class="s">"."</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"Listing subdir/parent/child"</span><span class="p">)</span>
+ <span class="k">for</span> <span class="nx">_</span><span class="p">,</span> <span class="nx">entry</span> <span class="o">:=</span> <span class="k">range</span> <span class="nx">c</span> <span class="p">{</span>
+ <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" "</span><span class="p">,</span> <span class="nx">entry</span><span class="p">.</span><span class="nx">Name</span><span class="p">(),</span> <span class="nx">entry</span><span class="p">.</span><span class="nx">IsDir</span><span class="p">())</span>
+ <span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p><code>cd</code> back to where we started.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">err</span> <span class="p">=</span> <span class="nx">os</span><span class="p">.</span><span class="nx">Chdir</span><span class="p">(</span><span class="s">"../../.."</span><span class="p">)</span>
+ <span class="nx">check</span><span class="p">(</span><span class="nx">err</span><span class="p">)</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p>We can also visit a directory <em>recursively</em>,
+including all its sub-directories. <code>Walk</code> accepts
+a callback function to handle every file or
+directory visited.</p>
+
+ </td>
+ <td class="code leading">
+
+ <div class="highlight"><pre> <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">"Visiting subdir"</span><span class="p">)</span>
+ <span class="nx">err</span> <span class="p">=</span> <span class="nx">filepath</span><span class="p">.</span><span class="nx">Walk</span><span class="p">(</span><span class="s">"subdir"</span><span class="p">,</span> <span class="nx">visit</span><span class="p">)</span>
+<span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ <tr>
+ <td class="docs">
+ <p><code>visit</code> is called for every file or directory found
+recursively by <code>filepath.Walk</code>.</p>
+
+ </td>
+ <td class="code">
+
+ <div class="highlight"><pre><span class="kd">func</span> <span class="nx">visit</span><span class="p">(</span><span class="nx">p</span> <span class="kt">string</span><span class="p">,</span> <span class="nx">info</span> <span class="nx">os</span><span class="p">.</span><span class="nx">FileInfo</span><span class="p">,</span> <span class="nx">err</span> <span class="kt">error</span><span class="p">)</span> <span class="kt">error</span> <span class="p">{</span>
+ <span class="k">if</span> <span class="nx">err</span> <span class="o">!=</span> <span class="kc">nil</span> <span class="p">{</span>
+ <span class="k">return</span> <span class="nx">err</span>
+ <span class="p">}</span>
+ <span class="nx">fmt</span><span class="p">.</span><span class="nx">Println</span><span class="p">(</span><span class="s">" "</span><span class="p">,</span> <span class="nx">p</span><span class="p">,</span> <span class="nx">info</span><span class="p">.</span><span class="nx">IsDir</span><span class="p">())</span>
+ <span class="k">return</span> <span class="kc">nil</span>
+<span class="p">}</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ </table>
+
+ <table>
+
+ <tr>
+ <td class="docs">
+
+ </td>
+ <td class="code">
+
+ <div class="highlight"><pre><span class="gp">$</span> go run directories.go
+<span class="go">Listing subdir/parent</span>
+<span class="go"> child true</span>
+<span class="go"> file2 false</span>
+<span class="go"> file3 false</span>
+<span class="go">Listing subdir/parent/child</span>
+<span class="go"> file4 false</span>
+<span class="go">Visiting subdir</span>
+<span class="go"> subdir true</span>
+<span class="go"> subdir/file1 false</span>
+<span class="go"> subdir/parent true</span>
+<span class="go"> subdir/parent/child true</span>
+<span class="go"> subdir/parent/child/file4 false</span>
+<span class="go"> subdir/parent/file2 false</span>
+<span class="go"> subdir/parent/file3 false</span>
+</pre></div>
+
+ </td>
+ </tr>
+
+ </table>
+
+
+ <p class="next">
+ Next example: <a href="command-line-arguments">Command-Line Arguments</a>.
+ </p>
+
+ <p class="footer">
+ by <a href="https://markmcgranaghan.com">Mark McGranaghan</a> | <a href="https://github.com/mmcgrana/gobyexample/blob/master/examples/directories">source</a> | <a href="https://github.com/mmcgrana/gobyexample#license">license</a>
+ </p>
+ </div>
+ </body>
+</html>
diff --git a/public/file-paths b/public/file-paths
index 65e3886..f7b24a1 100644
--- a/public/file-paths
+++ b/public/file-paths
@@ -229,7 +229,7 @@ be made relative to base.</p>
<p class="next">
- Next example: <a href="command-line-arguments">Command-Line Arguments</a>.
+ Next example: <a href="directories">Directories</a>.
</p>
<p class="footer">
diff --git a/public/index.html b/public/index.html
index ef6fe69..b11b9ef 100644
--- a/public/index.html
+++ b/public/index.html
@@ -143,6 +143,8 @@
<li><a href="file-paths">File Paths</a></li>
+ <li><a href="directories">Directories</a></li>
+
<li><a href="command-line-arguments">Command-Line Arguments</a></li>
<li><a href="command-line-flags">Command-Line Flags</a></li>