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arping sends ARP requests to a neighboring host. This won't work if there is an ARP subnet gateway in the middle. If there is, you'll just get the gateway's MAC address not the host's address you are really trying to get to.
Shows all block devices in a tree with descruptions of what they are.
host B (you) redirects a modem port (62220) to his local ssh.
host A is a remote machine (the ones that issues the ssh cmd).
once connected port 5497 is in listening mode on host B.
host B just do a
ssh 127.0.0.1 -p 5497 -l user
and reaches the remote host'ssh. This can be used also for vnc and so on.
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"
Friday is the 5th day of the week, monday is the 1st.
Output may be affected by locale.
"What it actually shows is going to be dependent on the commands you've previously entered.
When you do this, bash looks for the last command that you entered that contains the substring "ls", in my case that was "lsof ...". If the command that bash finds is what you're looking for, just hit Enter to execute it. You can also edit the command to suit your current needs before executing it (use the left and right arrow keys to move through it).
If you're looking for a different command, hit Ctrl+R again to find a matching command further back in the command history. You can also continue to type a longer substring to refine the search, since searching is incremental.
Note that the substring you enter is searched for throughout the command, not just at the beginning of the command." - http://www.linuxjournal.com/content/using-bash-history-more-efficiently
Uses mime-type of files rather than relying on file extensions to find files of a certain type.
This can obviously be extended to finding files of any other type as well.. like plain text files, audio, etc..
In reference to displaying the total hours of video (which was earlier posted in command line fu, but relied on the user having to supply all possible video file formats) we can now do better:
$ find ./ -type f -print0 | xargs -0 file -iNf - | grep video | cut -d: -f1 | xargs -d'\n' /usr/share/doc/mplayer/examples/midentify | grep ID_LENGTH | awk -F "=" '{sum += $2} END {print sum/60/60; print "hours"}'
Nothing special required, just wget, sed & tr!