Commands using sysctl (11)

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Remove lines that contain a specific pattern($1) from file($2).
The -i option in sed allows in-place editing of the input file. Replace myexpression with any regular expression. /expr/d syntax means if the expression matches then delete the line. You can reverse the functionality to keep matching lines only by using: $ sed -i -n '/myexpression/p' /path/to/file.txt

recursive transform all contents of files to lowercase
In this way it doesn't have problems with filenames with spaces.

execute your commands hiding secret bits from history records
$ wget --user=username --password="$password" http://example.org/ Instead of hiding commands entirely from history, I prefer to use "read" to put the password into a variable, and then use that variable in the commands instead of the password. Without the "-e" and "-s" it should work in any bourne-type shell, but the -s is what makes sure the password doesn't get echoed to the screen at all. (-e makes editing work a bit better)

Download all images on a 4chan thread

Not a kismet replacement...
If you're like some individuals who rely on ndiswrapper and cannot use kismet, this command may be of service. watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption'" Or... watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption' | egrep 'linksys'" :-) Hopefully you'll find some dd-wrt compatible routers.

List the size (in human readable form) of all sub folders from the current location

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" }

Install pip with Proxy
Installs pip packages defining a proxy

Email yourself a short note
I created this so I could send myself an email alert when a long-running job was finished, e.g., $ my_long_job.exe ; quickemail my_long_job.exe has finished

Split video files using avconv along keyframes


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