🔐 Karlo Luiten

Category: Linux

  • [FIX] vfs unable to mount root fs unknown-block

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    karlo
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    A RHEL update today fucked up a RHEL system, giving: “vfs unable to mount root fs unknown-block”. Fix: Boot from RHEL CD Choose rescue mode Start (with network) Type: chroot /mnt/sysimage (to work in the actual disk) Go and remove the oldest kernel, find oldest kernel by typing `rpm -q kernel` Remove by doing: `rpm…

  • Bash get full path of file

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    karlo
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    Get the full path of a file via: $ readlink -f ./file Tip: make an alias: alias fullpath=’readlink -f’

  • Dell Linux Dock display switcher script

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    karlo
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    This might be helpful for someone. A quick script I made for changing output modes on my Dell laptop. There are different configurations. laptop: laptop screen only vga: vga output + laptop screen mix: hdmi + vga output, laptop screen off dock: dell dock display setup #!/bin/bash LAPTOP=’LVDS-1′ DOCKLEFT=’DP-2′ DOCKRIGHT=’DP-1′ VGA=’VGA-1′ HDMI=’HDMI-1′ case $1 in…

  • Openssl encrypt & decrypt files

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    karlo
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    Encrypt: openssl enc -aes-256-cbc -a -salt -in plain.txt -out encrypted.enc Decrypt: openssl enc -d -aes-256-cbc -a -in encrypted.enc -out plain.txt Functions: #!/bin/bash function encrypt() { openssl enc -aes-256-cbc -a -salt -in $1 -out ${1}.enc ; stat $_ ; } function decrypt() { openssl enc -d -aes-256-cbc -a -in $1 -out $( echo $1 | sed…

  • Bash: SSL x509 check enddate / expiration time of certificate with openssl

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    karlo
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    You can check the endtime/end time/notafter/expiration date of a site by doing this: openssl s_client -connect google.com:443 2>/dev/null

  • Script: Puppet module create template

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    karlo
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    Adjust to your needs ;) #!/bin/bash # Create puppet module layout if [[ -z “$1” ]];then echo “$0 modulename” exit 1 fi if [[ -d $1 ]]; then echo “Dir already exists” exit 1 fi # Actual work M=$1 mkdir -p \ $M \ $M/files \ $M/manifests \ $M/templates # Files cat $M/manifests/${file}.pp done #…

  • FIX has missing requires of

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    karlo
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    From here.: yum check dependencies \ | grep ‘has missing requires’ \ | sed ‘s/.\+has missing requires of //’ \ | sed ‘s/ [=].\+//’ \ | while read dep; do yum -y install “$dep”; done

  • SSH: Don’t display motd and banner

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    karlo
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    Stop display of motd on login: # On the machine of which you don’t want to see the banner $ touch ~/.hushlogin Stop display of banner on ssh login: # Method 1: $ ssh -q targethost #Method 2: # Add to .ssh/config: Host * LogLevel Quiet

  • Reposync errors: empty rpm’s

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    karlo
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    I recently got empty rpm’s back from Red Hat. The system was registered properly. Problem was thet for reposync, I used a different .repo file. This file still had the old ssl/tls key sources. Update your reposync .repo file to reflect the current ssh/tls keys and things will work again :).

  • Backup and restore permissions linux (accidental chmod -R)

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    karlo
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    cd /etc/ chmod -R 664 . *SHIT!* If you find you did an accidental chmod -R, you may be able to restore it. Make sure SSH login keeps working (chmod -R 0600 /etc/ssh ) Install a similar machine On that machine, issue this command: find /etc/ -exec stat –format “[ ! -L \”{}\” ] &&…

  • A better todo.txt repeated task inserter

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    karlo
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    I have a scheduled.txt file like this: # Scheduled tasks for todo.txt # Format: # # a dow, Mon,Tue,Wed,… # b moy, Jan,Feb,Mar,… # d dom, 01..31 # D m/d/y 12/30/12 # F Y-m-d 2012-12-30 # j doy 001..366 # V woy 01..53 # # %2 = Division by 2 is possible # %N2= Devision…

  • Useful ‘command not found’ output for bash

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    karlo
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    Add this to your .bashrc: clippy() { echo “I see you’re trying to use the terminal …”; echo ” v “; echo ” ╭─╮”; echo ” ⌾ ⌾”; echo ” │▕│”; echo ” ╰─╯”; } function command_not_found_handle { clippy $1; } It will result in: $ adsf I see you’re trying to use the terminal…

  • [SOLVED] Add date (and seconds) to GNOME3 bar/clock

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    karlo
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    $ gsettings list-recursively | grep gnome.shell.clock org.gnome.shell.clock show-date false org.gnome.shell.clock show-seconds false Set via: $ gsettings set org.gnome.shell.clock show-date true $ gsettings set org.gnome.shell.clock show-seconds true

  • [SOLVED] Install native spotify on Fedora (with Spotify apps)(64bit+32bit)

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    karlo
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    This cost me some hours to find out, but I am currently using the native spotify linux preview under fedora 16, 64 bit: Steps: Make sure you don’t use spotify free. It will not work on linux. Install some things: $ sudo yum install qt-webkit perl-ExtUtils-MakeMaker libXScrnSaver nspr-devel openssl-devel For 64 bit, do: $sudo ln -s…

  • My tip: a temporary directory (for temporary files)

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    karlo
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    My tip: make a temporary directory for all kinds of random stuff. Downloads, quick notes et cetera. I use it a lot. By using a crontab like this, the old files (+5 days) are automatically deleted: $ find /home/karlo/temp/ -type f -mtime +5 -delete && find /home/karlo/temp/ -empty -delete

  • Import mp3 in audacity (on fedora)

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    karlo
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    Remove audacity (#yum remove audacity), install audacity-freeworld (#yum install audacity-freeworld ). That’s it. You might have to enable RPMFusion.

  • Clear BASH history

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    karlo
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    Clear the BASH history easily via: $ >~/.bash_history Remember to log out after doing this.

  • ifconfig gone (command not found)

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    karlo
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    Today, ifconfig was not working for me. I think this happened after I installed X11 on my headless server. $ ifconfig bash: ifconfig: command not found It turns out something removed /sbin from my $PATH. Read more about the $PATH here. The ifconfig-command resides in /sbin: $ whereis ifconfig ifconfig: /sbin/ifconfig The solution is to…

  • Use $top over SSH

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    karlo
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    If you want to use `top` over SSH, use the -t option: $ ssh -t servername top This also works if you want to use `tail -f` over ssh: $ ssh -t servername “tail -f”