diff --git a/20210416/.test.txt b/20210416/.test.txt
new file mode 100644
index 0000000000000000000000000000000000000000..dd38ed5746e36cb495b0589c1aad5b9965213322
--- /dev/null
+++ b/20210416/.test.txt
@@ -0,0 +1 @@
+Punkt-Test
diff --git a/20210416/calculate b/20210416/calculate
new file mode 100755
index 0000000000000000000000000000000000000000..6c1b049e082bb2e273ce8564aa1855a4e3d22a1e
--- /dev/null
+++ b/20210416/calculate
@@ -0,0 +1,5 @@
+#!/usr/bin/bc -q
+
+2 ^ 50 / 10 / 1000 / 1000 / 1000000
+
+quit
diff --git a/20210416/cd.. b/20210416/cd..
new file mode 100644
index 0000000000000000000000000000000000000000..a78009bddcd58844651bae68a847faa7a88b16ff
--- /dev/null
+++ b/20210416/cd..
@@ -0,0 +1,3 @@
+#pwd
+cd ..
+#pwd
diff --git a/20210416/chmod-1.txt b/20210416/chmod-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..82cb694b3f2d06ea812ad0fb38c3bf7006320138
--- /dev/null
+++ b/20210416/chmod-1.txt
@@ -0,0 +1,11 @@
+-rwxr-xr-x 1 peter peter   16 Apr 16 14:20 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> chmod 750 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l cd..
+-rwxr-x--- 1 peter peter 16 Apr 16 14:20 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> chmod 644 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l cd..
+-rw-r--r-- 1 peter peter 16 Apr 16 14:20 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> chmod 660 cd..
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l cd..
+-rw-rw---- 1 peter peter 16 Apr 16 14:20 cd..
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/find-1.txt b/20210416/find-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d25cf3ecb6f4e00db781582781fb1bde4c8e0337
--- /dev/null
+++ b/20210416/find-1.txt
@@ -0,0 +1,25 @@
+cassini/home/peter/bo/2021ss/bs/20210416> find . -name "*.txt"
+./shell-scripts-4.txt
+./shell-scripts-2.txt
+./test-3.txt
+./shell-scripts-3.txt
+./symlinks-3.txt
+./wildcards-1.txt
+./wildcards-3.txt
+./shell-scripts-5.txt
+./shell-scripts-6.txt
+./hardlinks-1.txt
+./.test.txt
+./test/hello.txt
+./chmod-1.txt
+./wildcards-2.txt
+./hardlinks-2.txt
+./shell-scripts-1.txt
+./symlinks-4.txt
+./mount-1.txt
+./test-1.txt
+./grep-3.txt
+./grep-1.txt
+./symlinks-1.txt
+./symlinks-2.txt
+./grep-2.txt
diff --git a/20210416/find-2.txt b/20210416/find-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..d7ada2377c15702784a99f4441e28d2f6f180a91
--- /dev/null
+++ b/20210416/find-2.txt
@@ -0,0 +1,3 @@
+cassini/home/peter/bo/2021ss/bs/20210416> find . -name *.txt
+find: paths must precede expression: `find-1.txt'
+find: possible unquoted pattern after predicate `-name'?
diff --git a/20210416/find-3.txt b/20210416/find-3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..0f7d97e84cc857573d34ca0ce3ab56009ae806a9
--- /dev/null
+++ b/20210416/find-3.txt
@@ -0,0 +1,3 @@
+cassini/home/peter/bo/2021ss/bs/20210416> echo find . -name *.txt
+find . -name chmod-1.txt find-1.txt find-2.txt grep-1.txt grep-2.txt grep-3.txt hardlinks-1.txt hardlinks-2.txt mount-1.txt shell-scripts-1.txt shell-scripts-2.txt shell-scripts-3.txt shell-scripts-4.txt shell-scripts-5.txt shell-scripts-6.txt symlinks-1.txt symlinks-2.txt symlinks-3.txt symlinks-4.txt test-1.txt test-3.txt wildcards-1.txt wildcards-2.txt wildcards-3.txt
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/find-4.txt b/20210416/find-4.txt
new file mode 100644
index 0000000000000000000000000000000000000000..a37fc2419524f4210312f004311a4e408249f50a
--- /dev/null
+++ b/20210416/find-4.txt
@@ -0,0 +1,30 @@
+cassini/home/peter/bo/2021ss/bs/20210416> find . -name "*".txt
+./shell-scripts-4.txt
+./shell-scripts-2.txt
+./test-3.txt
+./shell-scripts-3.txt
+./symlinks-3.txt
+./wildcards-1.txt
+./wildcards-3.txt
+./shell-scripts-5.txt
+./shell-scripts-6.txt
+./hardlinks-1.txt
+./.test.txt
+./test/hello.txt
+./chmod-1.txt
+./wildcards-2.txt
+./find-1.txt
+./hardlinks-2.txt
+./shell-scripts-1.txt
+./symlinks-4.txt
+./mount-1.txt
+./test-1.txt
+./grep-3.txt
+./find-2.txt
+./grep-1.txt
+./symlinks-1.txt
+./find-3.txt
+./symlinks-2.txt
+./grep-2.txt
+cassini/home/peter/bo/2021ss/bs/20210416> echo find . -name "*".txt
+find . -name *.txt
diff --git a/20210416/grep-1.txt b/20210416/grep-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..22f5ddbcc91d31c3c94e5a56fe1b188b3416a47c
--- /dev/null
+++ b/20210416/grep-1.txt
@@ -0,0 +1,10 @@
+cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *.*
+hello.c:  printf ("Hello, world!\n");
+unix-20210416.tex:        printf ("Hello, world!\n");
+unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *
+hello.c:  printf ("Hello, world!\n");
+test/hello.txt:Hello, world!
+unix-20210416.tex:        printf ("Hello, world!\n");
+unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/grep-2.txt b/20210416/grep-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..289385dce7aed9ba4d32ef1388f5cc7e1b9a2cc5
--- /dev/null
+++ b/20210416/grep-2.txt
@@ -0,0 +1,30 @@
+cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello .*
+./hello.c:  printf ("Hello, world!\n");
+./test/hello.txt:Hello, world!
+./grep-1.txt:cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *.*
+./grep-1.txt:hello.c:  printf ("Hello, world!\n");
+./grep-1.txt:unix-20210416.tex:        printf ("Hello, world!\n");
+./grep-1.txt:unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+./grep-1.txt:cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *
+./grep-1.txt:hello.c:  printf ("Hello, world!\n");
+./grep-1.txt:test/hello.txt:Hello, world!
+./grep-1.txt:unix-20210416.tex:        printf ("Hello, world!\n");
+./grep-1.txt:unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+../20210416/hello.c:  printf ("Hello, world!\n");
+../20210416/test/hello.txt:Hello, world!
+../20210416/grep-1.txt:cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *.*
+../20210416/grep-1.txt:hello.c:  printf ("Hello, world!\n");
+../20210416/grep-1.txt:unix-20210416.tex:        printf ("Hello, world!\n");
+../20210416/grep-1.txt:unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+../20210416/grep-1.txt:cassini/home/peter/bo/2021ss/bs/20210416> grep -r Hello *
+../20210416/grep-1.txt:hello.c:  printf ("Hello, world!\n");
+../20210416/grep-1.txt:test/hello.txt:Hello, world!
+../20210416/grep-1.txt:unix-20210416.tex:        printf ("Hello, world!\n");
+../20210416/grep-1.txt:unix-20210416.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+../20210409/unix-20210409.tex:        printf ("Hello, world!\n");
+../20210409/unix-20210409.tex:      Text schreiben: \lstinline[style=cmd]{echo "Hello, world!"}
+../20210409/hello.c:  printf ("Hello, world!\n");
+../20210409/shell-variables-2.txt:Hello, world!
+../20210409/shell-variables-2.txt:Hello, world!
+../20210409/shell-variables-2.txt:Hello, world!
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/grep-3.txt b/20210416/grep-3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ef1b9bcb456ddd649688ab35c9d0205f1e08b7e8
--- /dev/null
+++ b/20210416/grep-3.txt
@@ -0,0 +1,2 @@
+cassini/home/peter/bo/2021ss/bs/20210416> echo grep -r Hello .*
+grep -r Hello . .. .test.txt
diff --git a/20210416/hardlinks-1.txt b/20210416/hardlinks-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..8409d2346d3e36524d80858a3c3adfe73638b194
--- /dev/null
+++ b/20210416/hardlinks-1.txt
@@ -0,0 +1,22 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ln test-2.txt test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 12:30 test-1.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 2
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-2.txt
+Test 2
+cassini/home/peter/bo/2021ss/bs/20210416> echo "Test 1" > test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-2.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 14:47 test-1.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 14:47 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/hardlinks-2.txt b/20210416/hardlinks-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..4234e50e40d8e70d7c4b066619772ee03a030601
--- /dev/null
+++ b/20210416/hardlinks-2.txt
@@ -0,0 +1,10 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 14:47 test-1.txt
+-rw-r--r-- 2 peter peter  7 Apr 16 14:47 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416>
+cassini/home/peter/bo/2021ss/bs/20210416> rm test-2.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 14:47 test-1.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/hello b/20210416/hello
new file mode 100755
index 0000000000000000000000000000000000000000..9f3f770bfcccad3d62d2e2d08b077469ef3722fa
--- /dev/null
+++ b/20210416/hello
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+echo "Hello, world!"
diff --git a/20210416/hello.c b/20210416/hello.c
new file mode 100644
index 0000000000000000000000000000000000000000..b19d80e9bd0bd7c5ed8f54b20c6a50d9166f03ac
--- /dev/null
+++ b/20210416/hello.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  return 0;
+}
diff --git a/20210416/mount-1.txt b/20210416/mount-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..07569eed45c93309e18b24047b6ede82cc6e572d
--- /dev/null
+++ b/20210416/mount-1.txt
@@ -0,0 +1,21 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -lh ~/Www/Was\ läuft\ falsch\ in\ der\ gegenwärtigen\ Physik-99hVAu1k6G8.mp4
+-rw-r--r-- 1 peter peter 155M Mai 20  2019 '/home/peter/Www/Was läuft falsch in der gegenwärtigen Physik-99hVAu1k6G8.mp4'
+cassini/home/peter/bo/2021ss/bs/20210416> cp -pi ~/Www/Was\ läuft\ falsch\ in\ der\ gegenwärtigen\ Physik-99hVAu1k6G8.mp4 /media/usb
+usb/  usb0/ usb1/ usb2/ usb3/ usb4/ usb5/ usb6/ usb7/
+cassini/home/peter/bo/2021ss/bs/20210416> cp -pi ~/Www/Was\ läuft\ falsch\ in\ der\ gegenwärtigen\ Physik-99hVAu1k6G8.mp4 /media/usb
+usb/  usb0/ usb1/ usb2/ usb3/ usb4/ usb5/ usb6/ usb7/
+cassini/home/peter/bo/2021ss/bs/20210416> cp -pi ~/Www/Was\ läuft\ falsch\ in\ der\ gegenwärtigen\ Physik-99hVAu1k6G8.mp4 /media/usb3/
+cassini/home/peter/bo/2021ss/bs/20210416> mount | grep usb
+cassini/home/peter/bo/2021ss/bs/20210416> mount /media/usb3/
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l /media/usb3/
+insgesamt 4
+-rwxr-xr-x 1 peter peter 40 Dez  3 10:52  nm.txt
+-rwxr-xr-x 1 peter peter  0 Apr 16 12:52 'Was läuft falsch in der gegenwärtigen Physik-99hVAu1k6G8.mp4'
+cassini/home/peter/bo/2021ss/bs/20210416> cp -pi ~/Www/Was\ läuft\ falsch\ in\ der\ gegenwärtigen\ Physik-99hVAu1k6G8.mp4 /media/usb3/
+cp: '/media/usb3/Was läuft falsch in der gegenwärtigen Physik-99hVAu1k6G8.mp4' überschreiben? y
+cassini/home/peter/bo/2021ss/bs/20210416> umount /media/usb3
+cassini/home/peter/bo/2021ss/bs/20210416> mount /media/usb3
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l /media/usb3/                                   insgesamt 158284
+-rwxr-xr-x 1 peter peter        40 Dez  3 10:52  nm.txt
+-rwxr-xr-x 1 peter peter 162077261 Mai 20  2019 'Was läuft falsch in der gegenwärtigen Physik-99hVAu1k6G8.mp4'
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-1.txt b/20210416/shell-scripts-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..b979d46e4f71249407571cfb7ab41266ace543cf
--- /dev/null
+++ b/20210416/shell-scripts-1.txt
@@ -0,0 +1,4 @@
+cassini/home/peter/bo/2021ss/bs/20210416> cat cd..
+cd ..
+cassini/home/peter/bo/2021ss/bs/20210416> cd..
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-2.txt b/20210416/shell-scripts-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..e936daff4c8aa6b6a7b92fea5e799934775a384e
--- /dev/null
+++ b/20210416/shell-scripts-2.txt
@@ -0,0 +1,8 @@
+cassini/home/peter/bo/2021ss/bs/20210416> cat cd..
+pwd
+cd ..
+pwd
+cassini/home/peter/bo/2021ss/bs/20210416> cd..
+/home/peter/bo/2021ss/bs/20210416
+/home/peter/bo/2021ss/bs
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-3.txt b/20210416/shell-scripts-3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..64dede0649d842d112ae1906ad37922195a1e7e2
--- /dev/null
+++ b/20210416/shell-scripts-3.txt
@@ -0,0 +1,8 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l hello
+-rw-r--r-- 1 peter peter 21 Apr 16 14:24 hello
+cassini/home/peter/bo/2021ss/bs/20210416> cat hello
+echo "Hello, world!"
+cassini/home/peter/bo/2021ss/bs/20210416> chmod 755 hello
+cassini/home/peter/bo/2021ss/bs/20210416> ./hello
+Hello, world!
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-4.txt b/20210416/shell-scripts-4.txt
new file mode 100644
index 0000000000000000000000000000000000000000..25ea052a0d5a80be46b4f74add0e124405818bd7
--- /dev/null
+++ b/20210416/shell-scripts-4.txt
@@ -0,0 +1,7 @@
+cassini/home/peter/bo/2021ss/bs/20210416> cat hello
+#!/bin/bash
+
+echo "Hello, world!"
+cassini/home/peter/bo/2021ss/bs/20210416> ./hello
+Hello, world!
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-5.txt b/20210416/shell-scripts-5.txt
new file mode 100644
index 0000000000000000000000000000000000000000..aa400eecbf5755993f45ce1dd6fd2ff2f7ea189a
--- /dev/null
+++ b/20210416/shell-scripts-5.txt
@@ -0,0 +1,14 @@
+cassini/home/peter/bo/2021ss/bs/20210416> cat calculate
+#!/usr/bin/bc
+
+2 ^ 50 / 10 / 1000 / 1000 / 1000000
+cassini/home/peter/bo/2021ss/bs/20210416> ./calculate
+bc 1.07.1
+Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006, 2008, 2012-2017 Free Software Foundation, Inc.
+This is free software with ABSOLUTELY NO WARRANTY.
+For details type `warranty'.
+112
+^C
+(interrupt) use quit to exit.
+quit
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/shell-scripts-6.txt b/20210416/shell-scripts-6.txt
new file mode 100644
index 0000000000000000000000000000000000000000..21e310e492618b7214d4250c021ff09d0912f5c1
--- /dev/null
+++ b/20210416/shell-scripts-6.txt
@@ -0,0 +1,9 @@
+cassini/home/peter/bo/2021ss/bs/20210416> cat calculate
+#!/usr/bin/bc -q
+
+2 ^ 50 / 10 / 1000 / 1000 / 1000000
+
+quit
+cassini/home/peter/bo/2021ss/bs/20210416> ./calculate
+112
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/symlinks-1.txt b/20210416/symlinks-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..082d37fa47a06228a3255eeaa972542ac7451342
--- /dev/null
+++ b/20210416/symlinks-1.txt
@@ -0,0 +1,12 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-1.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-3.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> rm test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-3.txt
+cat: test-3.txt: Datei oder Verzeichnis nicht gefunden
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/symlinks-2.txt b/20210416/symlinks-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..242cce4d34d87cad7cc23266bfc2d0117cedab63
--- /dev/null
+++ b/20210416/symlinks-2.txt
@@ -0,0 +1,7 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 14:39 test-1.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 3
+cassini/home/peter/bo/2021ss/bs/20210416> ln -s test-1.txt test-3.txt
diff --git a/20210416/symlinks-3.txt b/20210416/symlinks-3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ed65d60c82beacea126d25a2758bdaea38209808
--- /dev/null
+++ b/20210416/symlinks-3.txt
@@ -0,0 +1,9 @@
+cassini/home/peter/bo/2021ss/bs/20210416> rm test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ln -s test-3.txt test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:42 test-1.txt -> test-3.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+cat: test-1.txt: Zu viele Ebenen aus symbolischen Links
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/symlinks-4.txt b/20210416/symlinks-4.txt
new file mode 100644
index 0000000000000000000000000000000000000000..74f32b7209380d08764304ca550414aca15a07db
--- /dev/null
+++ b/20210416/symlinks-4.txt
@@ -0,0 +1,12 @@
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:42 test-1.txt -> test-3.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+cat: test-1.txt: Zu viele Ebenen aus symbolischen Links
+cassini/home/peter/bo/2021ss/bs/20210416>
+cassini/home/peter/bo/2021ss/bs/20210416> rm test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l test-*.txt
+-rw-r--r-- 1 peter peter  7 Apr 16 12:30 test-2.txt
+lrwxrwxrwx 1 peter peter 10 Apr 16 14:37 test-3.txt -> test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/test-1.txt b/20210416/test-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..ac5ab8fbdb5f9b410cba904145f975593182dced
--- /dev/null
+++ b/20210416/test-1.txt
@@ -0,0 +1 @@
+Test 1
diff --git a/20210416/test-3.txt b/20210416/test-3.txt
new file mode 120000
index 0000000000000000000000000000000000000000..e512c20fae491086c36ada7e2b276df83e32b1bd
--- /dev/null
+++ b/20210416/test-3.txt
@@ -0,0 +1 @@
+test-1.txt
\ No newline at end of file
diff --git a/20210416/test/hello.txt b/20210416/test/hello.txt
new file mode 100644
index 0000000000000000000000000000000000000000..af5626b4a114abcb82d63db7c8082c3c4756e51b
--- /dev/null
+++ b/20210416/test/hello.txt
@@ -0,0 +1 @@
+Hello, world!
diff --git a/20210416/unix-20210416.tex b/20210416/unix-20210416.tex
new file mode 120000
index 0000000000000000000000000000000000000000..8548cff5b6f4928e1bacf91d66f0f6d1ed4966da
--- /dev/null
+++ b/20210416/unix-20210416.tex
@@ -0,0 +1 @@
+../20210409/unix-20210409.tex
\ No newline at end of file
diff --git a/20210416/wildcards-1.txt b/20210416/wildcards-1.txt
new file mode 100644
index 0000000000000000000000000000000000000000..8061b6b72fc36090136db19921dee2154b9a350a
--- /dev/null
+++ b/20210416/wildcards-1.txt
@@ -0,0 +1,36 @@
+cassini/home/peter/bo/2021ss/bs/20210416> echo "Test 1" > test-1.txt
+cassini/home/peter/bo/2021ss/bs/20210416> echo "Test 2" > test-2.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-2.txt
+Test 2
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l
+insgesamt 16
+lrwxrwxrwx 1 peter peter   27 Apr 16 10:27 bs-20210416.pdf -> ../20210409/bs-20210409.pdf
+-rw-r--r-- 1 peter peter    0 Apr 16 11:53 cd..
+-rw-r--r-- 1 peter peter   82 Apr 16 12:20 hello.c
+drwxr-xr-x 2 peter peter 4096 Apr 16 12:25 test
+-rw-r--r-- 1 peter peter    7 Apr 16 12:26 test-1.txt
+-rw-r--r-- 1 peter peter    7 Apr 16 12:26 test-2.txt
+lrwxrwxrwx 1 peter peter   29 Apr 16 10:19 unix-20210416.pdf -> ../20210409/unix-20210409.pdf
+lrwxrwxrwx 1 peter peter   29 Apr 16 12:06 unix-20210416.tex -> ../20210409/unix-20210409.tex
+cassini/home/peter/bo/2021ss/bs/20210416> cd test
+cassini/home/peter/bo/2021ss/bs/20210416/test> cp -p ../test*.txt
+cassini/home/peter/bo/2021ss/bs/20210416/test> ls -l
+insgesamt 0
+cassini/home/peter/bo/2021ss/bs/20210416/test> cd ..
+cassini/home/peter/bo/2021ss/bs/20210416> ls -l
+insgesamt 16
+lrwxrwxrwx 1 peter peter   27 Apr 16 10:27 bs-20210416.pdf -> ../20210409/bs-20210409.pdf
+-rw-r--r-- 1 peter peter    0 Apr 16 11:53 cd..
+-rw-r--r-- 1 peter peter   82 Apr 16 12:20 hello.c
+drwxr-xr-x 2 peter peter 4096 Apr 16 12:25 test
+-rw-r--r-- 1 peter peter    7 Apr 16 12:26 test-1.txt
+-rw-r--r-- 1 peter peter    7 Apr 16 12:26 test-2.txt
+lrwxrwxrwx 1 peter peter   29 Apr 16 10:19 unix-20210416.pdf -> ../20210409/unix-20210409.pdf
+lrwxrwxrwx 1 peter peter   29 Apr 16 12:06 unix-20210416.tex -> ../20210409/unix-20210409.tex
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-2.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416>
diff --git a/20210416/wildcards-2.txt b/20210416/wildcards-2.txt
new file mode 100644
index 0000000000000000000000000000000000000000..fd44a83a02fa5e15b2f724db7d140033573849b7
--- /dev/null
+++ b/20210416/wildcards-2.txt
@@ -0,0 +1,3 @@
+cassini/home/peter/bo/2021ss/bs/20210416/test> echo cp -p ../test*.txt
+cp -p ../test-1.txt ../test-2.txt
+cassini/home/peter/bo/2021ss/bs/20210416/test>
diff --git a/20210416/wildcards-3.txt b/20210416/wildcards-3.txt
new file mode 100644
index 0000000000000000000000000000000000000000..7abffc8939b9354ca8079e8249a3e3fbb5a9d30e
--- /dev/null
+++ b/20210416/wildcards-3.txt
@@ -0,0 +1,14 @@
+cassini/home/peter/bo/2021ss/bs/20210416> for x in 1 2 3; do echo "Test $x" > test-$x.txt; donecassini/home/peter/bo/2021ss/bs/20210416> ls -l test*.txt
+-rw-r--r-- 1 peter peter 7 Apr 16 12:30 test-1.txt
+-rw-r--r-- 1 peter peter 7 Apr 16 12:30 test-2.txt
+-rw-r--r-- 1 peter peter 7 Apr 16 12:30 test-3.txt
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-1.txt
+Test 1
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-2.txt
+Test 2
+cassini/home/peter/bo/2021ss/bs/20210416> cat test-3.txt
+Test 3
+cassini/home/peter/bo/2021ss/bs/20210416> cd test/
+cassini/home/peter/bo/2021ss/bs/20210416/test> cp -p ../test*.txt
+cp: das angegebene Ziel '../test-3.txt' ist kein Verzeichnis
+cassini/home/peter/bo/2021ss/bs/20210416/test>
diff --git a/projekte.txt b/projekte.txt
index 9117431c5499cfbc47ec3efe8787d7dcfdbc01b3..21956a5cfdc5b8c74c6e2d2979f85cffe6dccd36 100644
--- a/projekte.txt
+++ b/projekte.txt
@@ -22,3 +22,9 @@
  - Mumble-Client: Forward-Error-Correction aktivierbar machen
  - PULT auf übersichtlichere und effizientere Weise neu programmieren
  * Docker für PULT
+ - Komfortable Fernsteuerung von Rechnern von Teilnehmenden über VNC in PULT
+ - Komfortable Fernsteuerung von Rechnern von Teilnehmenden über VNC in BBB
+ - Work Advanture für die Hochschule installieren
+   Bsp-Instanz aus Bochum (von dem dortigen Hackspace): https://virtuallab.das-labor.org/
+   Doku dazu: https://howto.rc3.world/workadventure.en.html
+ - Treiber für freies Smartphone