goedel:~ emullen$ ssh emullen@klaatu.cs.washington.edu
Enter passphrase for key '/Users/emullen/.ssh/id_rsa': 
Last login: Mon Apr 10 11:18:18 2017 from goedel.dyn.cs.washington.edu
[emullen@klaatu ~]$ ls
directory.txt  hamlet.txt
[emullen@klaatu ~]$ sed -E -e 's/Hamlet/Kanye/g' hamlet.txt > kanye.txt
[emullen@klaatu ~]$ less kanye.txt 
[emullen@klaatu ~]$ emacs kanye.txt 
[emullen@klaatu ~]$ sed -E -e 's/(Hamlet|HAMLET)/Kanye/g' hamlet.txt > kanye.txt
[emullen@klaatu ~]$ emacs kanye.txt 
[emullen@klaatu ~]$ sed -E -e 's/(Hamlet|HAMLET|Ham.)/Kanye/g' hamlet.txt > kanye.txt
[emullen@klaatu ~]$ sed -E -e 's/(Hamlet|HAMLET|Ham\.)/Kanye/g' hamlet.txt > kanye.txt
[emullen@klaatu ~]$ emacs kanye.txt 
[emullen@klaatu ~]$ sed -E -e 's/Hamlet/Kanye/g' -e 's/HAMLET/KANYE/g' -e 's/Ham(\.)/Kan\1/g' hamlet.txt > kanye.txt
[emullen@klaatu ~]$ emacs kanye.txt 
[emullen@klaatu ~]$ ls
directory.txt  hamlet.txt  kanye.txt
[emullen@klaatu ~]$ cat directory.txt 
Mullen, Eric emullen@cs.washington.edu CSE218
Perkins, Hal perkins@cs.washington.edu CSE548
Tatlock, Zach ztatlock@cs.washington.edu CSE546
Gremlin, The gremlin@cs.washington.edu CSE000

[emullen@klaatu ~]$ sed -E -e 's/([a-zA-Z]*)(, )([a-zA-Z]*)/\3 \1/g' directory.txt > names.txt
[emullen@klaatu ~]$ emacs names.txt 
[emullen@klaatu ~]$ sed -E -e 's/([a-zA-Z]*), ([a-zA-Z]*).*/\2 \1/g' directory.txt > names.txt
[emullen@klaatu ~]$ emacs names.txt 
[emullen@klaatu ~]$ emacs directory.txt 
[emullen@klaatu ~]$ sed -E -e 's/([a-zA-Z]*), ([a-zA-Z]*).*/\2 \1/g' directory.txt > names.txt
[emullen@klaatu ~]$ emacs names.txt 
[emullen@klaatu ~]$ cat directory.txt 
Mullen, Eric emullen@cs.washington.edu, CSE218
Perkins, Hal perkins@cs.washington.edu, CSE548
Tatlock, Zach ztatlock@cs.washington.edu, CSE546
Gremlin, The gremlin@cs.washington.edu, CSE000

[emullen@klaatu ~]$ sed -E -e 's/.* ([a-zA-Z\.]*@[a-zA-Z\.]*).*/\1/g' directory.txt > emails.txt
[emullen@klaatu ~]$ emacs emails.txt 
[emullen@klaatu ~]$ sed -E -e 's/.*([a-zA-Z\.]*@[a-zA-Z\.]*).*/\1/g' directory.txt > emails.txt
[emullen@klaatu ~]$ emacs emails.txt 
[emullen@klaatu ~]$ sed -E -e 's/.*([a-zA-Z\.]+@[a-zA-Z\.]*).*/\1/g' directory.txt > emails.txt
[emullen@klaatu ~]$ emacs emails.txt 
[emullen@klaatu ~]$ sed -E -e 's/.* ([a-zA-Z\.]+@[a-zA-Z\.]*).*/\1/g' directory.txt > emails.txt
[emullen@klaatu ~]$ emacs emails.txt