Kevin Hatfield's Blog

Unix commands cheat list

This is nothing more than a place for me to jot down all the *nix commands that I have a hard time remembering. It is not a tutorial, and all the information here is to be used at your own risk. The commands here are used for either freeBSD 5.3, OS X 10.3 or both.

1. Flush the DNS cache:

lookupd -flushcache

2. Run CPAN in shell mode:

perl -MCPAN -e shell

3. Start, Stop, Restart Apache:

apachectl start
apachectl stop
apachectl restart

4. Shutdown and reboot:

shutdown -R now

5. Show disk space:

df -k (in Kb)
df -m (in Mb)
df -g (in Gb)

6. Show disk usage:

du -hc

7. Show disk usage one folder deep:

du -hc -d1

8. Show running processes:

ps aux

9. Edit the Apache configurations file (for freeBSD):

pico /usr/local/etc/apache/httpd.conf

10. Edit the Apache configurations file (for OS X):

pico /private/etc/httpd/httpd.conf (for Apache 1.3)

11. Run the install utility for freeBSD:

/stand/sysinstall

12. Rebuild the access or virtualusertable databases after editing /etc/mail/access or /etc/mail/virtusertable :

make maps

13. Dump a MySQL database:

mysqldump -u USER -pPASSWORD DBNAME > filename.sql

14. Import from a dump file into MySQL:

mysql -u USER -p DBNAME < filename.sql

15. Grab your most important configuration files and email them to yourself:

tar cvfz - /etc/rc.conf /etc/master.passwd /etc/fstab /usr/local/etc | uuencode seedfiles.tgz | mail -s “Web Server Seed Files” someguy@someserver.com

16. Configure Apache 2 from source with the proper modules:

sudo ./configure --prefix=/apache2 --enable-cgi=yes --enable-cgid=yes --enable-dav=yes --enable-expires=yes --enable-headers=yes --enable-info=yes --enable-rewrite=yes --enable-so=yes --enable-speling=yes --enable-ssl=yes --enable-usertrack=yes --enable-vhost-alias=yes

17. Change the mySQL password:

mysqladmin -u root password 'new password goes here'

18. rsync for dummies:

rsync -r --stats --progress --exclude 'some wildcard' /from/some/folder /to/some/other/folder

19. PHP5 on OS X:

http://www.entropy.ch/software/macosx/php/ has a ready to run installer with every possible option turned on. Saves a hell of a lot of hassle.

20. CVS – How to set the CVSROOT in bash:

Put this in .bashrc:
CVSROOT=/usr/local/cvsroot
export CVSROOT

21. CVS – How to set your default editor to pico instead of vi:

EDITOR=pico
export EDITOR

22. CVS – Checkout

(from the folder you want to hold the checked out code)

cvs checkout project

23. CVS – Commit

(from within the working folder)

cvs commit

It will open pico so you can type an explanation of the changes commited.

24. CVS – Refresh working copy

(from within the working folder)

cvs update

I don’t trust this one 100%, so every now and then I re-check out the source.

25. Webmin

A great way to easily manage *nix servers is Webmin. I use it on both freeBSD and it is pretty damn nice. While some of its modules are a bit rustic, overall it beats the hell out of having to use the CLI for annoying stuff.

26. Split a file based on a separation string

csplit -k -f output_file_prefix source_file_name '/separation string/' {99}

99 is the number of times top repeat the command. In the unix flavor of split you can do {*}, but OS X doesn’t like it so I am setting it to 99.

27. Run the Apache Bench:

ab -n100 -c20 http://www.mydomain.com/

Where 100 is the number of iterations and 20 is the number of concurrent hits.

28. Default admin web site for Smoothwall Express:

https://smoothwall.yourdomain.com:441/

29. Recursive find:

find . -iname "*\?*"

finds anything with the escaped character (in this case a question mark) within your current folder.

30. ftp upload from command line:

This one falls under “annoying quirks of OS X.” I wasted over one hour trying to decypher the man page for ftp for 10.4 because it would not let me upload a file from a compressed one-line command within a bash script. Here is the one that worked:

ftp -u ftp://$USER:$PASSWORD@$FTPSERVER/$FTPFOLDER/$REMOTE_FILENAME $LOCAL_FILENAME

This one worked like a champ.