Commands tagged kernel (36)

  • 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 7
  • Check if system is 32bit or 64bit


    16
    arch
    anapsix · 2013-01-02 17:52:14 5
  • 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 8
  • 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 6
  • 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 7
  • 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 27
  • 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 4
  • 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 22:32:29 237
  • 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 5
  • 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 3
  • 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 2
  • 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 5
  • 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 6
  • 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 6
  • 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 2
  • 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 2
  • 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 3
  • 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 2
  • 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 12
  • 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 8
  • 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 7
  • Developer: Add an IDT map design reference to your source tree

    Kernel developers might need to know what indices to map to the IOAPIC if building a new kernel from scratch. This command gives users a guide to go off of.


    1
    cp /proc/interrupts irq-ref.txt
    realkstrawn93 · 2022-02-23 19:53:02 268
  • 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 3
  • 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 4
  • 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 2
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encode HTML entities
Encodes HTML entities from input (file or stdin) so it's possible to directly past the result to a blog or HTML source file.

One command line web server on port 80 using nc (netcat)
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List your MACs address
List all MAC addresses on a Linux box. sort -u is useful when having virtual interfaces.

Get and read log from remote host (works with log on pipe, too)

DELETE all those duplicate files but one based on md5 hash comparision in the current directory tree
This one-liner will the *delete* without any further confirmation all 100% duplicates but one based on their md5 hash in the current directory tree (i.e including files in its subdirectories). Good for cleaning up collections of mp3 files or pictures of your dog|cat|kids|wife being present in gazillion incarnations on hd. md5sum can be substituted with sha1sum without problems. The actual filename is not taken into account-just the hash is used. Whatever sort thinks is the first filename is kept. It is assumed that the filename does not contain 0x00. As per the good suggestion in the first comment, this one does a hard link instead: $ find . -xdev -type f -print0 | xargs -0 md5sum | sort | perl -ne 'chomp; $ph=$h; ($h,$f)=split(/\s+/,$_,2); if ($h ne $ph) { $k = $f; } else { unlink($f); link($k, $f); }'

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Alternative size (human readable) of files and directories (biggest last)

Convert every eps in a directory to pdf
Converts every *.eps file to a *.pdf file

A signal trap that logs when your script was killed and what other processes were running at that time
trap is the bash builtin that allows you to execute commands when the current script receives a particular signal. Uses $0 for the script name, $$ for the script PID, tee to output to STDOUT as well as a log file and ps to log other running processes.

Rename .JPG to .jpg recursively
Recursively rename .JPG to .jpg using standard find and mv. It's generally better to use a standard tool if doing so is not much more difficult.

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