From: Gustav Eek <gustav.eek@fripost.org>
Date: Mon, 21 Jun 2021 11:44:05 +0000 (+0200)
Subject: [linux-intro] Complete example files
X-Git-Url: https://git.g-eek.se/?a=commitdiff_plain;h=08685aea03c3ed2076f6f26644d9487fa0eb4493;p=inbyggd-frihet-wiki.git

[linux-intro] Complete example files

Add an example script file which computes prime numbers, and complete
with a C version for execution efficiency comparison.
---

diff --git a/linux-intro/files/files.sh b/linux-intro/files/files.sh
index 35cf42b..69c6c95 100644
--- a/linux-intro/files/files.sh
+++ b/linux-intro/files/files.sh
@@ -11,6 +11,8 @@ folders="\
   05.avsl \
 "
 
+# Include example text file to each lesson
+
 text=text.txt
 
 for f in $folders; do
@@ -21,5 +23,11 @@ for f in $folders; do
     done
 done
 
+# Include script examples to lesson 4
+
+cp prime.sh prime.c $file/04.stil
+
+# Compress and cleanup
+
 tar -cvf $file.tar $file
 rm -fr $file
diff --git a/linux-intro/files/linux-intro.tar b/linux-intro/files/linux-intro.tar
index d89e455..527562b 100644
Binary files a/linux-intro/files/linux-intro.tar and b/linux-intro/files/linux-intro.tar differ
diff --git a/linux-intro/files/prime-again.sh b/linux-intro/files/prime-again.sh
new file mode 100644
index 0000000..116c1bb
--- /dev/null
+++ b/linux-intro/files/prime-again.sh
@@ -0,0 +1,16 @@
+#!/bin/env bash
+
+# Prints prime numbers, dividable evenly only by itself and one
+
+# Here are alternative methods
+
+N=99
+i=1; printf "%4d" $i
+i=2; printf "%4d" $i
+while [[ $i < $N ]]; do
+    i=$(( $i + 1 ))
+    if ! seq 2 $(( i - 1 )) | sed "s/^/$i%/" | bc | grep -q "^0$"; then
+        printf "%4d" $i
+    fi
+done
+printf "\n"
diff --git a/linux-intro/files/prime.c b/linux-intro/files/prime.c
new file mode 100644
index 0000000..639d4a8
--- /dev/null
+++ b/linux-intro/files/prime.c
@@ -0,0 +1,20 @@
+/* Prints prime numbers, dividable evenly only by itself and one */
+
+#include <stdio.h>
+
+#define N 99
+
+int main(void)
+{
+  int i, j;
+  i = 1;
+  printf ("%5d", i);
+  while (i < N)
+    {
+      i++;
+      j = 2;
+      while (i % j != 0) j++;
+      if (j == i) printf ("%5d", i);
+    }
+  printf ("\n");
+}
diff --git a/linux-intro/files/prime.sh b/linux-intro/files/prime.sh
new file mode 100644
index 0000000..2d91899
--- /dev/null
+++ b/linux-intro/files/prime.sh
@@ -0,0 +1,19 @@
+#!/bin/env bash
+
+# Prints prime numbers, dividable evenly only by itself and one
+
+N=99
+
+i=1
+printf "%5d" $i
+while [[ $i < $N ]]; do
+    i=$(( $i + 1 ))
+    j=2
+    while [[ $(( $i % $j )) != 0 ]]; do
+        j=$(( $j + 1 ))
+    done
+    if [[ $j = $i ]]; then
+        printf "%5d" $i
+    fi
+done
+printf "\n"