Commands tagged dns (35)

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Multiple SSH Tunnels
Thankfully, the ssh command allows you to specify multiple tunnels through the same server in one command. Remeber if you want a priviliged port on your machine, you must use root or sudo account.

Check for Firewall Blockage.
This is just one method of checking to see if an IP is blocked via IP tables or CSF. Simple and to the point. Replace xx.xx.xx.xx with the IP you wish to check.

get all Google ipv4 subnets for a iptables firewall for example
a bit shorter, parenthesis not needed but added for clarity

Find the package that installed a command

tail a log over ssh
This is also handy for taking a look at resource usage of a remote box. $ ssh -t remotebox top

Automaticly cd into directory
Makes bash-4.x like zsh. Automatic cd into a directory if a command with that name doesnt exists. Ready for your ~/.bashrc file

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"

Clean up poorly named TV shows.
Replace 'SHOWNAME' with the name of the TV show. Add -n to test the command without renaming files. Check the 'sample output'.

Print ASCII Character Chart
Prints out an ascii chart using builtin bash! Then formats using cat -t and column. The best part is: $ echo -e "${p: -3} \\0$(( $i/64*100 + $i%64/8*10 + $i%8 ))"; From: http://www.askapache.com/linux/ascii-codes-and-reference.html

Print process run time, average CPU usage, and maximum memory usage on exit
Bash has a built-in time command which provides less functionality than the real time command. Thus we reference /usr/bin/time directly. Since the command isn't very easy to remember you could alias it to something like "cputime" or even just "time".


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