Commands by totti (87)

  • Matched string reference in replacement text

    Use matched data and some other as replacement data Show Sample Output


    0
    echo "abcde" | sed 's/./& /g'
    totti · 2011-08-26 16:54:26 7
  • Notify on Battery power

    Works on Laptops, Desktop having communication b/w UPS & CPU Show Sample Output


    0
    NotifyOnBATTERY () { while :; do on_ac_power||notify-send "Running on BATTERY"; sleep 1m; done }
    totti · 2011-08-26 11:54:16 7
  • Download a set of files that are numbered


    0
    for i in `seq -w 1 50`; do wget --continue \ http://commandline.org.uk/images/posts/animal/$i.jpg; done
    totti · 2011-08-19 20:06:16 5
  • Get full from half remembered commands

    Show all commands having the part known by you. Eg: apropos pdf | less Show Sample Output


    2
    apropos <part_rember> | less
    totti · 2011-08-19 19:34:57 6
  • Alternative for basename using grep to extract file name

    fileName /path/to/file.ext quivalent to basename /path/to/file.ext Show Sample Output


    -1
    fileName() { echo "$1" | grep -o "[^/]*$"; }
    totti · 2011-08-19 18:16:22 3
  • Boot block devices as virtual devices in Virtual Box

    eg: VBoxManage internalcommands createrawvmdk -filename ~/.VBox_sdc.vmdk -rawdisk /dev/sdc In order to start virtual box using block devices, ( Or to boot from it) run as ROOT sudo VirtualBox Then add & select the vmdk file as a device. At last Start the virtual box. - This cmd needs to run once for a device. - See command 8936 to run with out using ROOT power and easy handling of Virtual m/c


    0
    VBoxManage internalcommands createrawvmdk -filename [path/to/file/name.vmdk] -rawdisk /dev/[block_device]
    totti · 2011-08-19 14:26:22 8
  • Find all videos under current directory using MIME a.k.a not using extension

    Videos are found using their MIME type. Thus no need to for an extension for the video file. This is a efficent version of "jnash" cmd (4086). Thanks for jnash. This cmd will only show video files while his cmd show files having "video" anywhere in path. Show Sample Output


    1
    allVideos() { find ./ -type f -print0 | xargs -0 file -iNf - | grep ": video/" | cut -d: -f1; }
    totti · 2011-08-19 11:58:59 3
  • What is the use of this switch ?

    Find the usage of a switch with out searching through the entire man page. Usage: manswitch [cmd] [switch] Eg: manswitch grep silent ____________________________ In simple words man <cmd> | grep "\-<switch>" Eg: man grep | grep "\-o" This is not a standard method but works. Show Sample Output


    1
    manswitch() { man $1 | grep -A5 "^ *\-$2"; }
    totti · 2011-08-19 08:36:54 5
  • Sort output by column

    (separator = $IFS)


    2
    ps aux | sort -nk 6
    totti · 2011-08-16 11:04:45 3
  • Check if your webserver supports gzip compression with curl


    6
    curl -I -H "Accept-Encoding: gzip,deflate" http://example.org
    totti · 2011-08-16 10:32:01 4
  • Highlight network TX, RX information change


    5
    watch -n 2 -d '/sbin/ifconfig eth0'
    totti · 2011-08-16 10:29:34 4
  • Boot from a block device without giving root privilege to Virtual Box

    Usage: VBoxBlockBoot [Virtual_Machine] [Block_device] Eg: VBoxBlockBoot WinXP /dev/sdc In another words vm=usb; usb=sdc;sudo umount /dev/$usb* ; sudo chmod 777 /dev/$usb ; VBoxManage storageattach $vm --medium ~/raw-HD-4-VB/$usb.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm $vm Where vm --> Name of the virtual machine to start usb --> Block device to use. (/dev/sdc) This can used after setup up a boot loader on to my USB pen drive or HDD (After creating Live USB). Here root privilege is needed but not granted to Virtual Box. Thus we can access all our VM.( If we run VBox as root we can't access our VMs). Root privilege is used to - Unmount the storage device - Chmod to full access (777) Requirements:- 1. Device information file (rawvmdk file) created by the following command. Need to run only once. Not bad to run many. VBoxCreateRawDisk() { VBoxManage internalcommands createrawvmdk -filename ~/.rawHD4VB_`basename "$1"`.vmdk -rawdisk "$1"; } 2. Root privilege to umount & chmod 3. Real storage medium (ie /dev/*) (Non-virtual such as USB HD, pen drive, a partition) 4. A virtual m/c already available (here "usb") vm=usb; usb=sdc;sudo umount /dev/$usb* ; sudo chmod 777 /dev/$usb ; VBoxManage storageattach $vm --medium ~/raw-HD-4-VB/$usb.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm $vm VBoxBlockBoot() { sudo umount "$2"*; sudo chmod 777 "$2"; VBoxManage storageattach "$1" --medium ~/.rawHD4VB_`basename "$2"`.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm "$1"; } Show Sample Output


    0
    VBoxBlockBoot() { sudo umount "$2"*; sudo chmod 777 "$2"; VBoxManage storageattach "$1" --medium ~/.rawHD4VB_`basename "$2"`.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm "$1";}
    totti · 2011-07-29 13:04:19 4
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Use tee to process a pipe with two or more processes
Tee can be used to split a pipe into multiple streams for one or more process to work it. You can add more " >()" for even more fun.

invoke MATLAB functions from command line
`-r script.m` also possible

Get a BOFH excuse
Gets a BOFH excuse from the BOFH excuse server (towel.blinkenlights.nl port 666), and passes it through sed and tr to get rid of telnet connection stuff.

Recursively lists all files in the current directory, except the ones in '.snapshot' directory
This can be useful for those who have mounted NetApp file-systems with snapshot activated.

Python version 3: Serve current directory tree at http://$HOSTNAME:8000/
In Python version 3, the module was merged into http.server. Gentlemen, change your aliases.

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.

Set access and modification timestamps of a file using another one as reference
atime and mtime timestamps of $FILE2 is changed according to the ones of $FILE1. If $FILE2 doesn't exist is created.

Save a file you edited in vim without the needed permissions
Calls sudo tee like all the other lines, but also automatically reloads the file. Optionally you can add command Wq :execute ':W' | :q and command WQ :Wq to make quitting easier

Retrieve the size of a file on a server
Downloads the entire file, but http servers don't always provide the optional 'Content-Length:' header, and ftp/gopher/dict/etc servers don't provide a filesize header at all.

Catch a proccess from a user and strace it.
It sits there in a loop waiting for a proccess from that user to spawn. When it does it will attach strace to it

Stay in the loop…

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