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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save date and time for each command in history
Date-time format: YYYY-MM-DD HH:MM:SS

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

create a simple version of ls with extended output
create a short alias for 'ls' with multi-column (-C), file type syntax additions (slashes after directories, @ for symlinks, etc... (-F), long format (-l), including hidden directories (all ./, ../, .svn, etc) (-a), show file-system blocks actually in use (-s), human readable file sizes (-h)

Recursively remove .svn directories from the current location

check open ports without netstat or lsof

Show a Package Version on RPM based distributions
if you want to see all information about a package use: rpm -qi pkgname full list of querytags can be accessed by the command: rpm --querytags you can also customize the query format how ever you like with using more querytags together along with escape sequences in "man printf"! you can also use more than one package name. for example this command shows name and version in to columns: rpm -q --queryformat %-30{NAME}%{VERSION}\\n pkg1 pkg2

converting vertical line to horizontal line

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" }

Decode base64-encoded file in one line of Perl
Another option is openssl.

Use top to monitor only all processes with the same name fragment 'foo'
top accecpts a comma separated list of PIDs.

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