Detailed Articles

Useful One Off Recipes

Disk Management

List directories from largest to smallest at the top level only. On older system h will not work and you must use k.

du -sh * | sort

Long Running Processes

Look for long running processes,

Information

Last

Last searches back through the file /var/log/wtmp  (or the file designated by the -f flag) and displays a list of all users logged in (and out) since that file was created. 

Lastb

Lastb is the same as last, except that by default it shows a log of the file /var/log/btmp, which contains all the bad login attempts.

Quck String Manipulation

Quick reference of manipulating standout,

echo "some_file_name.txt" | tr "_" " " # result will be "some file name.txt"
paste oldName.txt newName.txt > runMe.txt # connects line by line to contents of both files together

Integrity Checking

MD5

Check if a file is corrupt,

# On Ubuntu
md5sum /path/to/file

# On Solaris
digest -a md5 -v /path/to/file