From 39bdc8b891f3c5867f1689e10ce295939457c999 Mon Sep 17 00:00:00 2001
From: rasmus <rasmusbwr.prof@gmail.com>
Date: Fri, 31 Jan 2025 21:07:47 +0100
Subject: [PATCH] Add more to Hello World page

---
 src/App.vue                                   |  4 +-
 .../Fortran/Fortran_Hello_World.vue           | 80 +++++++++++++++++--
 src/components/Fortran/Fortran_Index.vue      | 14 ++--
 3 files changed, 81 insertions(+), 17 deletions(-)

diff --git a/src/App.vue b/src/App.vue
index 2526131..5dcabfd 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -20,7 +20,7 @@
     </div>
   </main>
 
-  <footer class="flex justify-center pt-10 mt-10 ">
-    Author: Rasmus B. W. Rasmussen
+  <footer class="flex justify-center pt-10 mt-10 inset-x-0 bottom-0">
+    Author: Still under construction
   </footer>
 </template>
\ No newline at end of file
diff --git a/src/components/Fortran/Fortran_Hello_World.vue b/src/components/Fortran/Fortran_Hello_World.vue
index fb8887a..eab917b 100644
--- a/src/components/Fortran/Fortran_Hello_World.vue
+++ b/src/components/Fortran/Fortran_Hello_World.vue
@@ -8,25 +8,91 @@
     <hr>
     <p></p>
 
-    <div class="px-3 py-2">
-    <pre class="language-fortran"><code class="text-sm">
+    <div>
+      <pre><code class="text-sm">
 program hello
   implicit none
-  write(*,*) 'Hello world!'
+  print *, 'Hello world!'
 end program hello
       </code></pre>
     </div>
 
-    <p>With modern compilers, running the newest Fortran standards, <span><code>write(*,*)</code> and <code>print</code></span>
-      will compile to the exact same assembly. So if you only need to print something to stdout, just use <span><code>print</code></span>
+    <p>In the good ol' days (before FORTRAN 77), when printing to console, you would write <span><code>write(*,*)</code></span>,
+      but with the release of FORTRAN 77, that became redundant, as you could use the newest keyword, <span><code>print</code></span>.</p>
+    <br>
+
+    <p>With modern compilers, running the newest Fortran standards, <span><code>write(*,*) 'Hello world!'</code> and <code>print *, 'Hello world!'</code></span>
+      will compile to the exact same assembly. So if you only need to print something to stdout, just use <span><code>print *</code></span>
       as it conveys the meaning of the code better. Plus we don't need the full functionality of <span><code>write(*,*)</code></span>
       in this example.</p>
+    <br>
 
     <div>
-      <pre class="language-fortran"><code class="text-sm">
+      <pre><code class="text-sm">
 $ gfortran -o hello main.f90
 $ ./hello
-&gt; Hello world!
+ Hello world!
+      </code></pre>
+    </div>
+
+    <p>Now, hear me out, why not spice up the program a little bit more? Maybe we want to print to stdout, or what if
+      we suddenly need to print an error message, and want that to be handled correctly by the terminal emulator?</p>
+    <br>
+    <p>Well, fret not my friend, because I have just the solution for you then. All we gotta do is to read from the
+      terminal, and then print out the value.</p>
+    <br>
+
+    <div>
+      <pre><code class="text-sm">
+program hello
+  implicit none
+
+  character(1000) :: usertxt
+  integer :: ios
+
+  print *, 'Input text here: '
+
+  read(*,"(A)", iostat=ios) usertxt
+  if(is_iostat_end(ios)) stop
+
+  print *, trim(usertxt)
+
+end program hello
+      </code></pre>
+    </div>
+
+    <p>So what we're seeing here, is that we have created two variables: <span><code>usertxt</code> and <code>ios</code></span>.
+      <span><code>usertxt</code></span> is the input we're reading from the terminal. Although since Fortran 90 doesn't
+      have an explicit string type, doesn't mean we can't read or write text, as the <span><code>character</code></span>
+      type is just an array of 1000 characters long. It doesn't have to be 1000 characters, but it's what I chose on a
+      whim.</p>
+    <br>
+
+    <p>The other variable, <span><code>ios</code></span>, I probably don't need to introduce, as it's just an integer.
+      But what control-flow this value holds, I feel is quite important, as a lot of file-based business logic makes
+      use of it.</p>
+    <br>
+
+    <p>Introducing, <span><code>iostat</code></span>. AKA, Input/Output Status Specifier. It indicates the status of the
+      I/O operation. If the integer is positive, it indicates an error code. If it's negative, it indicates an end of file
+      condition. If it's zero, then it does not indicate anything yet. No error, no End Of File, no particular condition
+      has triggered yet.</p>
+    <br>
+
+    <p>So in this case, where we check if <span><code>ios</code></span> is End Of File, then that means if we input an
+      End Of File key combination (Ctrl+D on Unix/Linux, and Ctrl+Z on Windows), then the program would stop immediately.
+      We use the <span><code>trim()</code></span> function to remove any trailing whitespaces. That's because, if you
+      make a character bigger than the actual text, it will be fille with whitespace after the text. So now the output
+      looks like this:</p>
+    <br>
+
+    <div>
+      <pre><code class="text-sm">
+$ gfortran -o hello main.f90
+$ ./hello
+ Input text here:
+Hello world :D
+ Hello world :D
       </code></pre>
     </div>
   </div>
diff --git a/src/components/Fortran/Fortran_Index.vue b/src/components/Fortran/Fortran_Index.vue
index ec4025a..76e90f9 100644
--- a/src/components/Fortran/Fortran_Index.vue
+++ b/src/components/Fortran/Fortran_Index.vue
@@ -6,17 +6,15 @@
   <div>
     <h1 class="text-3xl">Fortran</h1>
     <hr>
-    <p>Fortran, which stands for Formula Translation, is indeed an interesting language with a rich history. As one of
-      the oldest programming languages still in active use today, it has played a significant role in shaping the
-      development of modern computing. First introduced in the 1950s by a team at IBM led by John Backus, Fortran was
-      designed specifically for scientific and engineering applications, where its ability to efficiently handle
-      complex numerical computations proved invaluable.</p>
+    <p>Fortran (Formula Translation), is one of the ancient languages somehow still in use as of today. First introduced
+      in the 1950s by a team at IBM, Fortran was designed specifically for scientific and engineering applications,
+      where its ability to efficiently handle complex mathematical operations.</p>
     <br>
     <p>
       Over the years, Fortran has undergone numerous updates and revisions, with the most recent standard being Fortran
-      2018. Despite the rise of newer languages like C++, Java, and Python, Fortran remains a popular choice in many
-      fields, including physics, chemistry, meteorology, and engineering, due to its performance. Even Nvidia and Intel
-      are still developing their compilers, as well as FOSS compilers such as gfortran and lfortran.</p>
+      2023. Even with the popularity of newer languages, such as C++, Java, and Python, Fortran remains a popular choice
+      in many fields, including physics, chemistry, meteorology, and engineering, due to its performance. Even Nvidia
+      and Intel are still developing their compilers, as well as FOSS compilers such as gfortran and lfortran.</p>
     <br>
 
     <p>Table of contents:</p>