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Press Any Key to Continue
Halt script progress until a key has been pressed. Source: http://bash-hackers.org/wiki/doku.php/mirroring/bashfaq/065

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

check open ports without netstat or lsof

Schedule Nice Background Commands That Won't Die on Logout - Alternative to nohup and at
Check out the usage of 'trap', you may not have seen this one much. This command provides a way to schedule commands at certain times by running them after sleep finishes sleeping. In the example 'sleep 2h' sleeps for 2 hours. What is cool about this command is that it uses the 'trap' builtin bash command to remove the SIGHUP trap that normally exits all processes started by the shell upon logout. The 'trap 1' command then restores the normal SIGHUP behaviour. It also uses the 'nice -n 19' command which causes the sleep process to be run with minimal CPU. Further, it runs all the commands within the 2nd parentheses in the background. This is sweet cuz you can fire off as many of these as you want. Very helpful for shell scripts.

Update program providing java on Debian
Lets you set all the java alternatives at once to a matching version. Also has options for just changing the jre or the plugin.

find unreadable file

erase content from a cdrw

Last month
Work out last months value

uniq without pre-sorting
Reads stdin, and outputs each line only once - without sorting ahead of time. This does use more memory than your system's sort utility.

Count TCP States From Netstat
Counts TCP states from Netstat and displays in an ordered list.


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