diff --git a/04-pipefilter.html b/04-pipefilter.html
index 8331f4221..773061a3d 100644
--- a/04-pipefilter.html
+++ b/04-pipefilter.html
@@ -330,7 +330,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Pipes and Filters</h1>
-        <p>Last updated on 2024-04-12 |
+        <p>Last updated on 2024-09-26 |
 
         <a href="https://github.com/swcarpentry/shell-novice/edit/main/episodes/04-pipefilter.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -587,7 +587,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>The <code>-n</code> option specifies a numerical rather than an
 alphanumerical sort.</p>
@@ -701,7 +701,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>In the first example with <code>&gt;</code>, the string ‘hello’ is
 written to <code>testfile01.txt</code>, but the file gets overwritten
@@ -751,7 +751,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Option 3 is correct. For option 1 to be correct we would only run the
 <code>head</code> command. For option 2 to be correct we would only run
@@ -850,7 +850,7 @@ <h3 class="callout-title">Piping Commands Together</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Option 4 is the solution. The pipe character <code>|</code> is used
 to connect the output from one command to the input of another.
@@ -913,7 +913,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The <code>head</code> command extracts the first 5 lines from
 <code>animals.csv</code>. Then, the last 3 lines are extracted from the
@@ -976,7 +976,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1024,7 +1024,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <p>Option 4. is the correct answer. If you have difficulty understanding
 why, try running the commands, or sub-sections of the pipelines (make
@@ -1137,7 +1137,7 @@ <h3 class="callout-title">Removing Unneeded Files</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>This would remove <code>.txt</code> files with one-character
 names</li>
@@ -1168,9 +1168,11 @@ <h3 class="callout-title">Key Points</h3>
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
@@ -1243,7 +1245,7 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://swcarpentry.github.io/shell-novice/04-pipefilter.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/04-pipefilter.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-04-12",
+  "dateModified": "2024-09-26",
   "datePublished": "2024-09-26"
 }
 
diff --git a/05-loop.html b/05-loop.html
index ea6ed41a0..95d6117f9 100644
--- a/05-loop.html
+++ b/05-loop.html
@@ -541,7 +541,7 @@ <h3 class="callout-title">Write your own loop</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -611,7 +611,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -683,7 +683,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -724,7 +724,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -772,7 +772,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>The text from each file in turn gets written to the
 <code>alkanes.pdb</code> file. However, the file gets overwritten on
@@ -823,7 +823,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -1224,7 +1224,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -1272,7 +1272,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
diff --git a/07-find.html b/07-find.html
index f7c5f2db1..0fdb10c94 100644
--- a/07-find.html
+++ b/07-find.html
@@ -607,7 +607,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The correct answer is 3, because the <code>-w</code> option looks
 only for whole-word matches. The other options will also match ‘of’ when
@@ -705,7 +705,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <pre class="source"><code>grep -w $1 -r $2 | cut -d : -f 2 | cut -d , -f 1,3 &gt; $1.txt</code></pre>
 <p>Actually, you can swap the order of the two cut commands and it still
@@ -752,7 +752,7 @@ <h3 class="callout-title">Little Women</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Solutions </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <pre class="source"><code>for sis in Jo Meg Beth Amy
 do
@@ -1018,7 +1018,7 @@ <h3 class="callout-title">Matching and Subtracting</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>Option 1 is correct. Putting the match expression in quotes prevents
 the shell expanding it, so it gets passed to the <code>find</code>
@@ -1093,7 +1093,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Find all files with a <code>.dat</code> extension recursively from
 the current directory</li>
diff --git a/aio.html b/aio.html
index a53a28340..a513a852a 100644
--- a/aio.html
+++ b/aio.html
@@ -2901,7 +2901,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-04-pipefilter"><p>Content from <a href="04-pipefilter.html">Pipes and Filters</a></p>
 <hr>
-<p>Last updated on 2024-04-12 |
+<p>Last updated on 2024-09-26 |
 
         <a href="https://github.com/swcarpentry/shell-novice/edit/main/episodes/04-pipefilter.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <div class="text-end">
@@ -3160,7 +3160,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>The <code>-n</code> option specifies a numerical rather than an
 alphanumerical sort.</p>
@@ -3274,7 +3274,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>In the first example with <code>&gt;</code>, the string ‘hello’ is
 written to <code>testfile01.txt</code>, but the file gets overwritten
@@ -3326,7 +3326,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Option 3 is correct. For option 1 to be correct we would only run the
 <code>head</code> command. For option 2 to be correct we would only run
@@ -3431,7 +3431,7 @@ <h3 class="callout-title">Piping Commands Together</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Option 4 is the solution. The pipe character <code>|</code> is used
 to connect the output from one command to the input of another.
@@ -3496,7 +3496,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The <code>head</code> command extracts the first 5 lines from
 <code>animals.csv</code>. Then, the last 3 lines are extracted from the
@@ -3559,7 +3559,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3609,7 +3609,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <p>Option 4. is the correct answer. If you have difficulty understanding
 why, try running the commands, or sub-sections of the pipelines (make
@@ -3726,7 +3726,7 @@ <h3 class="callout-title">Removing Unneeded Files</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>This would remove <code>.txt</code> files with one-character
@@ -3760,9 +3760,11 @@ <h3 class="callout-title">Key Points</h3>
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
@@ -3994,7 +3996,7 @@ <h3 class="callout-title">Write your own loop</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4064,7 +4066,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -4138,7 +4140,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -4181,7 +4183,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -4231,7 +4233,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>The text from each file in turn gets written to the
@@ -4286,7 +4288,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -4693,7 +4695,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -4741,7 +4743,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -5813,7 +5815,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The correct answer is 3, because the <code>-w</code> option looks
 only for whole-word matches. The other options will also match ‘of’ when
@@ -5911,7 +5913,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <pre class="source"><code>grep -w $1 -r $2 | cut -d : -f 2 | cut -d , -f 1,3 &gt; $1.txt</code></pre>
 <p>Actually, you can swap the order of the two cut commands and it still
@@ -5958,7 +5960,7 @@ <h3 class="callout-title">Little Women</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Solutions </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <pre class="source"><code>for sis in Jo Meg Beth Amy
 do
@@ -6226,7 +6228,7 @@ <h3 class="callout-title">Matching and Subtracting</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>Option 1 is correct. Putting the match expression in quotes prevents
 the shell expanding it, so it gets passed to the <code>find</code>
@@ -6301,7 +6303,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Find all files with a <code>.dat</code> extension recursively from
diff --git a/index.html b/index.html
index 874151370..267898b7e 100644
--- a/index.html
+++ b/index.html
@@ -398,7 +398,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Windows
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Computers with Windows operating systems do not automatically have a
 Unix Shell program installed. In this lesson, we encourage you to use an
@@ -425,7 +425,7 @@ <h4 class="accordion-header" id="headingSolution2">
   MacOS
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>For a Mac computer running macOS Mojave or earlier releases, the
 default Unix Shell is Bash. For a Mac computer running macOS Catalina or
@@ -453,7 +453,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Linux
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>The default Unix Shell for Linux operating systems is usually Bash.
 On most versions of Linux, it is accessible by running the <a href="https://help.gnome.org/users/gnome-terminal/stable/" class="external-link">Gnome
diff --git a/instructor/04-pipefilter.html b/instructor/04-pipefilter.html
index e31c5fd82..df620c24d 100644
--- a/instructor/04-pipefilter.html
+++ b/instructor/04-pipefilter.html
@@ -330,7 +330,7 @@ <h2 class="accordion-header" id="flush-headingTwelve">
       </div>
       <hr></nav><main id="main-content" class="main-content"><div class="container lesson-content">
         <h1>Pipes and Filters</h1>
-        <p>Last updated on 2024-04-12 |
+        <p>Last updated on 2024-09-26 |
 
         <a href="https://github.com/swcarpentry/shell-novice/edit/main/episodes/04-pipefilter.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 
@@ -589,7 +589,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>The <code>-n</code> option specifies a numerical rather than an
 alphanumerical sort.</p>
@@ -703,7 +703,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>In the first example with <code>&gt;</code>, the string ‘hello’ is
 written to <code>testfile01.txt</code>, but the file gets overwritten
@@ -753,7 +753,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Option 3 is correct. For option 1 to be correct we would only run the
 <code>head</code> command. For option 2 to be correct we would only run
@@ -852,7 +852,7 @@ <h3 class="callout-title">Piping Commands Together</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Option 4 is the solution. The pipe character <code>|</code> is used
 to connect the output from one command to the input of another.
@@ -915,7 +915,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The <code>head</code> command extracts the first 5 lines from
 <code>animals.csv</code>. Then, the last 3 lines are extracted from the
@@ -978,7 +978,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -1026,7 +1026,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <p>Option 4. is the correct answer. If you have difficulty understanding
 why, try running the commands, or sub-sections of the pipelines (make
@@ -1139,7 +1139,7 @@ <h3 class="callout-title">Removing Unneeded Files</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>This would remove <code>.txt</code> files with one-character
 names</li>
@@ -1170,9 +1170,11 @@ <h3 class="callout-title">Key Points</h3>
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
@@ -1245,7 +1247,7 @@ <h3 class="callout-title">Key Points</h3>
   "url": "https://swcarpentry.github.io/shell-novice/instructor/04-pipefilter.html",
   "identifier": "https://swcarpentry.github.io/shell-novice/instructor/04-pipefilter.html",
   "dateCreated": "2014-10-22",
-  "dateModified": "2024-04-12",
+  "dateModified": "2024-09-26",
   "datePublished": "2024-09-26"
 }
 
diff --git a/instructor/05-loop.html b/instructor/05-loop.html
index b7213fd5c..3fa8da01e 100644
--- a/instructor/05-loop.html
+++ b/instructor/05-loop.html
@@ -543,7 +543,7 @@ <h3 class="callout-title">Write your own loop</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -613,7 +613,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -685,7 +685,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -726,7 +726,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -774,7 +774,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>The text from each file in turn gets written to the
 <code>alkanes.pdb</code> file. However, the file gets overwritten on
@@ -825,7 +825,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -1226,7 +1226,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -1274,7 +1274,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
diff --git a/instructor/07-find.html b/instructor/07-find.html
index 12b6f5b82..db60a76a1 100644
--- a/instructor/07-find.html
+++ b/instructor/07-find.html
@@ -609,7 +609,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The correct answer is 3, because the <code>-w</code> option looks
 only for whole-word matches. The other options will also match ‘of’ when
@@ -707,7 +707,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <pre class="source"><code>grep -w $1 -r $2 | cut -d : -f 2 | cut -d , -f 1,3 &gt; $1.txt</code></pre>
 <p>Actually, you can swap the order of the two cut commands and it still
@@ -754,7 +754,7 @@ <h3 class="callout-title">Little Women</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Solutions </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <pre class="source"><code>for sis in Jo Meg Beth Amy
 do
@@ -1020,7 +1020,7 @@ <h3 class="callout-title">Matching and Subtracting</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>Option 1 is correct. Putting the match expression in quotes prevents
 the shell expanding it, so it gets passed to the <code>find</code>
@@ -1095,7 +1095,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal"><li>Find all files with a <code>.dat</code> extension recursively from
 the current directory</li>
diff --git a/instructor/aio.html b/instructor/aio.html
index 8fd67225c..d64dc85a6 100644
--- a/instructor/aio.html
+++ b/instructor/aio.html
@@ -2937,7 +2937,7 @@ <h3 class="callout-title">Key Points</h3>
 </div>
 </section></section><section id="aio-04-pipefilter"><p>Content from <a href="04-pipefilter.html">Pipes and Filters</a></p>
 <hr>
-<p>Last updated on 2024-04-12 |
+<p>Last updated on 2024-09-26 |
 
         <a href="https://github.com/swcarpentry/shell-novice/edit/main/episodes/04-pipefilter.md" class="external-link">Edit this page <i aria-hidden="true" data-feather="edit"></i></a></p>
 <p>Estimated time: <i aria-hidden="true" data-feather="clock"></i> 35 minutes</p>
@@ -3197,7 +3197,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>The <code>-n</code> option specifies a numerical rather than an
 alphanumerical sort.</p>
@@ -3311,7 +3311,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>In the first example with <code>&gt;</code>, the string ‘hello’ is
 written to <code>testfile01.txt</code>, but the file gets overwritten
@@ -3363,7 +3363,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>Option 3 is correct. For option 1 to be correct we would only run the
 <code>head</code> command. For option 2 to be correct we would only run
@@ -3468,7 +3468,7 @@ <h3 class="callout-title">Piping Commands Together</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
 <div class="accordion-body">
 <p>Option 4 is the solution. The pipe character <code>|</code> is used
 to connect the output from one command to the input of another.
@@ -3533,7 +3533,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
 <div class="accordion-body">
 <p>The <code>head</code> command extracts the first 5 lines from
 <code>animals.csv</code>. Then, the last 3 lines are extracted from the
@@ -3596,7 +3596,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb39">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -3646,7 +3646,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
 <div class="accordion-body">
 <p>Option 4. is the correct answer. If you have difficulty understanding
 why, try running the commands, or sub-sections of the pipelines (make
@@ -3763,7 +3763,7 @@ <h3 class="callout-title">Removing Unneeded Files</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>This would remove <code>.txt</code> files with one-character
@@ -3797,9 +3797,11 @@ <h3 class="callout-title">Key Points</h3>
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
@@ -4032,7 +4034,7 @@ <h3 class="callout-title">Write your own loop</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <div class="codewrapper sourceCode" id="cb7">
 <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i><i aria-hidden="true" data-feather="chevron-right"></i>
@@ -4102,7 +4104,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <p>The first code block gives the same output on each iteration through
 the loop. Bash expands the wildcard <code>*.pdb</code> within the loop
@@ -4176,7 +4178,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Show me the solution </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so any file name starting with the letter c, followed by
@@ -4219,7 +4221,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>4 is the correct answer. <code>*</code> matches zero or more
 characters, so a file name with zero or more characters before a letter
@@ -4269,7 +4271,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>The text from each file in turn gets written to the
@@ -4324,7 +4326,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution6" aria-expanded="false" aria-controls="collapseSolution6">
   <h4 class="accordion-header" id="headingSolution6"> Show me the solution </h4>
 </button>
-<div id="collapseSolution6" class="accordion-collapse collapse" data-bs-parent="#accordionSolution6" aria-labelledby="headingSolution6">
+<div id="collapseSolution6" class="accordion-collapse collapse" aria-labelledby="headingSolution6" data-bs-parent="#accordionSolution6">
 <div class="accordion-body">
 <p>3 is the correct answer. <code>&gt;&gt;</code> appends to a file,
 rather than overwriting it with the redirected output from a command.
@@ -4731,7 +4733,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution7" aria-expanded="false" aria-controls="collapseSolution7">
   <h4 class="accordion-header" id="headingSolution7"> Show me the solution </h4>
 </button>
-<div id="collapseSolution7" class="accordion-collapse collapse" data-bs-parent="#accordionSolution7" aria-labelledby="headingSolution7">
+<div id="collapseSolution7" class="accordion-collapse collapse" aria-labelledby="headingSolution7" data-bs-parent="#accordionSolution7">
 <div class="accordion-body">
 <p>The second version is the one we want to run. This prints to screen
 everything enclosed in the quote marks, expanding the loop variable name
@@ -4779,7 +4781,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution8" aria-expanded="false" aria-controls="collapseSolution8">
   <h4 class="accordion-header" id="headingSolution8"> Show me the solution </h4>
 </button>
-<div id="collapseSolution8" class="accordion-collapse collapse" data-bs-parent="#accordionSolution8" aria-labelledby="headingSolution8">
+<div id="collapseSolution8" class="accordion-collapse collapse" aria-labelledby="headingSolution8" data-bs-parent="#accordionSolution8">
 <div class="accordion-body">
 <p>We have a nested loop, i.e. contained within another loop, so for
 each species in the outer loop, the inner loop (the nested loop)
@@ -5853,7 +5855,7 @@ <h3 class="code-label">OUTPUT<i aria-hidden="true" data-feather="chevron-left"><
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution1" aria-expanded="false" aria-controls="collapseSolution1">
   <h4 class="accordion-header" id="headingSolution1"> Show me the solution </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
 <div class="accordion-body">
 <p>The correct answer is 3, because the <code>-w</code> option looks
 only for whole-word matches. The other options will also match ‘of’ when
@@ -5951,7 +5953,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution2" aria-expanded="false" aria-controls="collapseSolution2">
   <h4 class="accordion-header" id="headingSolution2"> Show me the solution </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
 <div class="accordion-body">
 <pre class="source"><code>grep -w $1 -r $2 | cut -d : -f 2 | cut -d , -f 1,3 &gt; $1.txt</code></pre>
 <p>Actually, you can swap the order of the two cut commands and it still
@@ -5998,7 +6000,7 @@ <h3 class="callout-title">Little Women</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution3" aria-expanded="false" aria-controls="collapseSolution3">
   <h4 class="accordion-header" id="headingSolution3"> Solutions </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
 <div class="accordion-body">
 <pre class="source"><code>for sis in Jo Meg Beth Amy
 do
@@ -6266,7 +6268,7 @@ <h3 class="callout-title">Matching and Subtracting</h3>
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution4" aria-expanded="false" aria-controls="collapseSolution4">
   <h4 class="accordion-header" id="headingSolution4"> Show me the solution </h4>
 </button>
-<div id="collapseSolution4" class="accordion-collapse collapse" data-bs-parent="#accordionSolution4" aria-labelledby="headingSolution4">
+<div id="collapseSolution4" class="accordion-collapse collapse" aria-labelledby="headingSolution4" data-bs-parent="#accordionSolution4">
 <div class="accordion-body">
 <p>Option 1 is correct. Putting the match expression in quotes prevents
 the shell expanding it, so it gets passed to the <code>find</code>
@@ -6341,7 +6343,7 @@ <h3 class="code-label">BASH<i aria-hidden="true" data-feather="chevron-left"></i
 <button class="accordion-button solution-button collapsed" type="button" data-bs-toggle="collapse" data-bs-target="#collapseSolution5" aria-expanded="false" aria-controls="collapseSolution5">
   <h4 class="accordion-header" id="headingSolution5"> Show me the solution </h4>
 </button>
-<div id="collapseSolution5" class="accordion-collapse collapse" data-bs-parent="#accordionSolution5" aria-labelledby="headingSolution5">
+<div id="collapseSolution5" class="accordion-collapse collapse" aria-labelledby="headingSolution5" data-bs-parent="#accordionSolution5">
 <div class="accordion-body">
 <ol style="list-style-type: decimal">
 <li>Find all files with a <code>.dat</code> extension recursively from
diff --git a/instructor/index.html b/instructor/index.html
index c908c33f2..056150edb 100644
--- a/instructor/index.html
+++ b/instructor/index.html
@@ -468,7 +468,7 @@ <h4 class="accordion-header" id="headingSolution1">
   Windows
   </h4>
 </button>
-<div id="collapseSolution1" class="accordion-collapse collapse" aria-labelledby="headingSolution1" data-bs-parent="#accordionSolution1">
+<div id="collapseSolution1" class="accordion-collapse collapse" data-bs-parent="#accordionSolution1" aria-labelledby="headingSolution1">
 <div class="accordion-body">
 <p>Computers with Windows operating systems do not automatically have a
 Unix Shell program installed. In this lesson, we encourage you to use an
@@ -495,7 +495,7 @@ <h4 class="accordion-header" id="headingSolution2">
   MacOS
   </h4>
 </button>
-<div id="collapseSolution2" class="accordion-collapse collapse" aria-labelledby="headingSolution2" data-bs-parent="#accordionSolution2">
+<div id="collapseSolution2" class="accordion-collapse collapse" data-bs-parent="#accordionSolution2" aria-labelledby="headingSolution2">
 <div class="accordion-body">
 <p>For a Mac computer running macOS Mojave or earlier releases, the
 default Unix Shell is Bash. For a Mac computer running macOS Catalina or
@@ -523,7 +523,7 @@ <h4 class="accordion-header" id="headingSolution3">
   Linux
   </h4>
 </button>
-<div id="collapseSolution3" class="accordion-collapse collapse" aria-labelledby="headingSolution3" data-bs-parent="#accordionSolution3">
+<div id="collapseSolution3" class="accordion-collapse collapse" data-bs-parent="#accordionSolution3" aria-labelledby="headingSolution3">
 <div class="accordion-body">
 <p>The default Unix Shell for Linux operating systems is usually Bash.
 On most versions of Linux, it is accessible by running the <a href="https://help.gnome.org/users/gnome-terminal/stable/" class="external-link">Gnome
diff --git a/instructor/key-points.html b/instructor/key-points.html
index 2f7a6b1dc..b2221db2d 100644
--- a/instructor/key-points.html
+++ b/instructor/key-points.html
@@ -457,9 +457,11 @@ <h2 class="accordion-header" id="flush-headingTwelve">
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
diff --git a/key-points.html b/key-points.html
index 3cc4f43ed..78f7d2bbd 100644
--- a/key-points.html
+++ b/key-points.html
@@ -455,9 +455,11 @@ <h2 class="accordion-header" id="flush-headingTwelve">
 <li>
 <code>sort</code> sorts its inputs.</li>
 <li>
-<code>head</code> displays the first 10 lines of its input.</li>
+<code>head</code> displays the first 10 lines of its input by
+default without additional arguments.</li>
 <li>
-<code>tail</code> displays the last 10 lines of its input.</li>
+<code>tail</code> displays the last 10 lines of its input by default
+without additional arguments.</li>
 <li>
 <code>command &gt; [file]</code> redirects a command’s output to a
 file (overwriting any existing content).</li>
diff --git a/md5sum.txt b/md5sum.txt
index 03198216c..eea9a3ee2 100644
--- a/md5sum.txt
+++ b/md5sum.txt
@@ -6,7 +6,7 @@
 "episodes/01-intro.md" "f9424965b4e7855f0e569be741c5e88e" "site/built/01-intro.md" "2023-06-09"
 "episodes/02-filedir.md" "14a1c573a9731344ede0c6ff854d953b" "site/built/02-filedir.md" "2024-07-24"
 "episodes/03-create.md" "cda7949aecf6bfe600e559f27319cc71" "site/built/03-create.md" "2024-03-08"
-"episodes/04-pipefilter.md" "61967f54e7798bbcb152dfc6787afcce" "site/built/04-pipefilter.md" "2024-04-12"
+"episodes/04-pipefilter.md" "e1c92193a59ec25ad054078348391b5d" "site/built/04-pipefilter.md" "2024-09-26"
 "episodes/05-loop.md" "7ea3b6c5e96b1cd2ddeb0b176c1b4be1" "site/built/05-loop.md" "2024-09-26"
 "episodes/06-script.md" "166572403e3b5f1c314ce7c52babb7b5" "site/built/06-script.md" "2023-08-05"
 "episodes/07-find.md" "b2c592366ea5a5c9a654ba13ec5765d1" "site/built/07-find.md" "2023-11-09"
diff --git a/pkgdown.yml b/pkgdown.yml
index 2e7939b18..f59f1563d 100644
--- a/pkgdown.yml
+++ b/pkgdown.yml
@@ -2,4 +2,4 @@ pandoc: 3.1.11
 pkgdown: 2.1.1
 pkgdown_sha: ~
 articles: {}
-last_built: 2024-09-26T01:49Z
+last_built: 2024-09-26T02:01Z