Commands tagged kernel (37)

  • Check if system is 32bit or 64bit

    Needed a quick way to see if my server distro that I setup years ago was running 32bit or not, since with time I had forgotten. Note: does not check _hardware_ e.g. /proc/cpuinfo but rather the kernel installed Show Sample Output


    21
    getconf LONG_BIT
    varghjarta · 2012-12-12 23:51:51 3
  • Check if system is 32bit or 64bit


    16
    arch
    anapsix · 2013-01-02 17:52:14 3
  • Remove all unused kernels with apt-get

    This should do the same thing and is about 70 chars shorter. Show Sample Output


    8
    aptitude remove $(dpkg -l|egrep '^ii linux-(im|he)'|awk '{print $2}'|grep -v `uname -r`)
    dbbolton · 2010-06-10 21:23:00 4
  • Remove all unused kernels with apt-get

    Note the double space: "...^ii␣␣linux-image-2..." Like 5813, but fixes two bugs: [1]This leaves the meta-packages 'linux-headers-generic' and 'linux-image-generic' alone so that automatic upgrades work correctly in the future. [2]Kernels newer than the currently running one are left alone (this can happen if you didn't reboot after installing a new kernel). I'm bummed that this took 228 characters. I'd like to see a simpler version. Show Sample Output


    7
    aptitude remove $(dpkg -l|awk '/^ii linux-image-2/{print $2}'|sed 's/linux-image-//'|awk -v v=`uname -r` 'v>$0'|sed 's/-generic//'|awk '{printf("linux-headers-%s\nlinux-headers-%s-generic\nlinux-image-%s-generic\n",$0,$0,$0)}')
    __ · 2010-12-11 11:38:15 3
  • Reload all sysctl variables without reboot

    Use `sysctl -p` without argument will only load /etc/sysctl.conf, but user configs always put in /etc/sysctl.d/*.conf, `sysctl --system` will load all the config files


    7
    sysctl --system
    tankywoo · 2015-01-29 07:56:36 1
  • Get current stable kernel version string from kernel.org

    depends on "jq" This is more reliable in my opinion. Show Sample Output


    5
    curl -s https://www.kernel.org/releases.json | jq '.latest_stable.version' -r
    ernierasta · 2019-03-06 08:48:04 0
  • Remove all unused kernels with apt-get

    This will remove all installed kernels on your debian based install, except the one you're currently using. From: http://tuxtweaks.com/2009/12/remove-old-kernels-in-ubuntu/comment-page-1/#comment-1590


    4
    dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d' | xargs sudo apt-get -y purge
    mitzip · 2010-06-10 20:33:32 0
  • List all installed kernels on Ubuntu except current one

    Lists all installed kernels minus the current one. This is useful to uninstall older kernels that take too much space on /boot partition. Show Sample Output


    4
    dpkg -l 'linux-*' | sed '/^ii/!d;/'"$(uname -r | sed "s/\(.*\)-\([^0-9]\+\)/\1/")"'/d;s/^[^ ]* [^ ]* \([^ ]*\).*/\1/;/[0-9]/!d'
    bugmenot · 2021-10-30 22:32:29 0
  • Remove all unused kernels with apt-get

    Remove old kernels (*-generic and *-generic-pae) via apt-get on debian/ubuntu based systems. Tested on ubuntu 10.04 - 12.04.


    3
    sudo apt-get remove $(dpkg -l|awk '/^ii linux-image-/{print $2}'|sed 's/linux-image-//'|awk -v v=`uname -r` 'v>$0'|sed 's/-generic*//'|awk '{printf("linux-headers-%s\nlinux-headers-%s-generic*\nlinux-image-%s-generic*\n",$0,$0,$0)}')
    mtron · 2012-08-15 10:02:12 1
  • Remove old kernel packages


    3
    dpkg -l linux-* | awk '/^ii/{ print $2}' | grep -v -e `uname -r | cut -f1,2 -d"-"` | grep -e [0-9] | xargs sudo apt-get -y purge
    yusufk · 2014-01-29 10:42:40 0
  • Display kernel profile of currently executing functions in Solaris.

    Lockstat will sample the kernel 977 times per second, and print out the functions that it sees executing on the CPU during the sample. The -s 10 switch tells lockstsat to not only print that function, but also show the call stack (up to 10 deep). Show Sample Output


    2
    lockstat -I -i 977 -s 30 -h sleep 1 > /tmp/profile.out
    garylittle · 2009-03-13 13:17:53 0
  • Remove all unused kernels with apt-get

    A little aptitude magic. Note: this will remove images AND headers. If you just want to remove images: aptitude remove ?and(~i~nlinux-im ?not(~n`uname -r`)) I used this in zsh without any problems. I'm not sure how other shells will interpret some of the special characters used in the aptitude search terms. Use -s to simulate.


    2
    aptitude remove ?and(~i~nlinux-(im|he) ?not(~n`uname -r`))
    dbbolton · 2010-06-11 22:57:09 0
  • Read funny developer comments in the Linux source tree

    These are way better than fortune(6). Show Sample Output


    2
    grep -2riP '\b(fuck|shit|bitch|tits|ass\b)' /usr/src/linux/
    h3xx · 2011-07-27 23:11:02 1
  • Remove all old kernels

    http://askubuntu.com/questions/89710/how-do-i-free-up-more-space-in-boot


    2
    sudo apt-get purge $(dpkg -l linux-{image,headers}-"[0-9]*" | awk '/ii/{print $2}' | grep -ve "$(uname -r | sed -r 's/-[a-z]+//')")
    funkjedi · 2015-03-15 15:57:19 1
  • Remove all unused kernels with apt-get

    TIMTOWTDI


    1
    perl -e 'chomp($k=`uname -r`); for (</boot/vm*>) {s/^.*vmlinuz-($k)?//; $l.="linux-image-$_ ";} system "aptitude remove $l";'
    dbbolton · 2010-06-10 22:16:47 0
  • Show linux kernel modules dependencies

    Use modprobe to list all the dependencies of a certain kernel module. Handy when debugging system issues. Show Sample Output


    1
    modprobe --show-depends module_name
    miguelcnf · 2012-08-17 16:54:52 0
  • Check if x86 Solaris based system is 32bit or 64bit

    This is likely only valid on Solaris based systems. Unfortunately a lot of the more universal techniques for determining if a system is 32bit or 64bit on x86 solaris fail to give much more information than "i86pc" Show Sample Output


    1
    isainfo -v
    halcyonblue · 2013-01-04 03:07:28 0
  • Reload all sysctl variables without reboot

    Reload all defined kernel variables from /etc/sysctl.conf(if no parameter after -p is given) without the old myth "Ah, you'll need to reboot to apply those variables"... Show Sample Output


    1
    /sbin/sysctl -p
    Risthel · 2013-02-14 12:48:26 0
  • Get version of loaded kernel module

    Returns the version of the kernel module specified as "MODULENAME", when available. Show Sample Output


    1
    lsmod | grep -io MODULENAME| xargs modinfo | grep -iw version
    adriano · 2013-03-18 07:52:14 0
  • Restrict the use of dmesg for current user/session

    Linux offers an interesting option to restrict the use of dmesg. It is available via /proc/sys/kernel/dmesg_restrict. You can check the status with: cat /proc/sys/kernel/dmesg_restrict Alternatively you can use sysctl: sudo sysctl -w kernel.dmesg_restrict=1 To make your change persistent across reboot, edit a fille in /etc/sysctl.d/.


    1
    sudo sh -c 'echo 1 > /proc/sys/kernel/dmesg_restrict'
    Blacksimon · 2015-03-13 20:54:45 0
  • Remove specific versions of old kernels (Ubuntu/Debian)

    If, for example, you want to remove all kernels and headers but the last three versions, you can't use one of that magic all-in-one "remove old stuff" commands. With this simple but elegant command you can remove a range of versions, or a list of versions with e.g. {14,16,20}. Show Sample Output


    1
    apt purge linux*{14..18}*
    ppq · 2016-04-20 07:44:55 0
  • Figure out if your kernel has an option enabled

    zless /proc/config.gz


    0
    zgrep CONFIG_MAGIC_SYSRQ /proc/config.gz
    h3xx · 2011-07-24 02:06:09 0
  • Adding kernel boot parameters after loading kernel and initrd

    Then exit from the shell. exit some time need to exit twice exit exit Now the OS will boot with the new parameters.


    0
    echo "root=/dev/sda7" > /proc/param.conf
    totti · 2011-09-27 18:06:53 0
  • Remove all unused kernels with apt-get

    since awk was already there one can use it instead of the 2 greps. might not be faster, but fast enough


    0
    apt-get remove $(dpkg -l | awk "/^ii linux-(image|headers)/ && ! /`uname -r`/ {print \$2}")
    _john · 2011-10-09 13:58:47 0
  • Install 4 new package files

    after kernel build with make deb-pkg, I like to install the 4 newest packages that exist in the directory. Beware: might be fewer for you....


    0
    sudo dpkg -i `ls -tr *.deb | tail -n4`
    _john · 2011-10-09 14:20:11 0
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Easily scp a file back to the host you're connecting from
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Configuring proxy client on terminal

Create a new file

Print the current time on the whole screen, updated every second
http://www.joachim-breitner.de/projects#screen-message now also supports reading stdin continuously to update what it shows, different ?slides? separated by a form feed character. Here, we feed the current time into it each second to create a large clock.

a function to create a box of '=' characters around a given string.
The function 'box' takes either one or two arguments. The first argument is a line of text to be boxed, the second argument (optional) is a character to use to draw the box. By default, the drawing character will be '='. The function 'n()' is a helper function used to draw the upper and lower lines of the box, its arguments are a length, and an character to print. (I used 'n' because 'line', 'ln' and 'l' are all commonly used)

List only the directories
to include hidden dirs use: $ tree -adL 1 (with ls, requires 'ls -ad */ .*/')

Recursive Line Count
We use `-not -name ".*"` for the reason we must omit hidden files (which unnecessary). We can only show up total lines like this: $ find * -type f -not -name ".*" | xargs wc -l | tail -1

Fast portscanner via Parallel

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.

Pipe STDOUT to vim
The hyphen tells vim to open from STDOUT - saves having to create temporary files.

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