Commands by alejandrone (1)

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commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

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Count the number of characters in a string from the standard input.

Set laptop display brightness
Run as root. Path may vary depending on laptop model and video card (this was tested on an Acer laptop with ATI HD3200 video). $ cat /proc/acpi/video/VGA/LCD/brightness to discover the possible values for your display.

tail: watch a filelog
-f file(s) to be monitorized -n number of last line to be printed on the screen in this example, the content of two files are displayed

Find the package that installed a command

Multi line grep using sed and specifying open/close tags
This line does not include your closing tag in the output.

Download all manuals RedHat 7 (CentOS/Fedora) with one command in Linux

archive all files containing local changes (svn)
Create a tgz archive of all the files containing local changes relative to a subversion repository. Add the '-q' option to only include files under version control: $svn st -q | cut -c 8- | sed 's/^/\"/;s/$/\"/' | xargs tar -czvf ../backup.tgz Useful if you are not able to commit yet but want to create a quick backup of your work. Of course if you find yourself needing this it's probably a sign you should be using a branch, patches or distributed version control (git, mercurial, etc..)

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" }

List all directories only.
Undocumented syntax, but should work on every shell. It'll list all directories in the current one. Change `*/` into globbing `**/` for recursivity.

View webcam output using GStreamer pipeline
Open a window that displays camera capture. Framerate, width and height may be changed to match your needs.


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