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Check whether laptop is running on battery or cable

find directory with most inodes/files
Find which directory in one filesystem that contains most inodes or files.

TCPDUMP & Save Capture to Remote Server w/ GZIP
NOTE: When opening the files you might need to strip the very top line with notepad++ as its a mistake header This is useful when the local machine where you need to do the packet capture with tcpdump doesn?t have enough room to save the file, where as your remote host does tcpdump -i eth0 -w - | ssh forge.remotehost.com -c arcfour,blowfish-cbc -C -p 50005 "cat - | gzip > /tmp/eth0.pcap.gz" Your @ PC1 doing a tcpdump of PC1s eth0 interface and its going to save the output @ PC2 who is called save.location.com to a file /tmp/eth0-to-me.pcap.gz again on PC2 More info @: http://www.kossboss.com/linuxtcpdump1

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Print a list of all hardlinks in the working directory, recursively
libpurple likes to hardlink files repeatedly. To ignore libpurple, use sed: | sed '/\.\/\.purple/d'

Reverse SSHfs mount,
While `sshfs $REMOTE_HOST:$REMOTE_PATH $LOCAL_PATH` "pulls" a directory from the remote server to the local host, the above command does the reverse and "pushes" a directory from the local host to the remote server. This makes use of the "slave" option of sshfs which instructs it to communicate over plain stdin/stdout and the `dpipe` tool from vde2 to connect the sftp-server stdout to the sshfs stdin and vice-versa.

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"

Unixtime
displays time in seconds since January 1, 1970 UTC

modify a file in place with perl
changes THIS to THAT in all files matching fileglob* without using secondary files

Mount directories in different locations
Like symlinked directories, you can mount a directory at a different location. For example mounting a directory from one location in to the http root without having to make your program follow symlinks or change permissions when reading.


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