Bash - Rambles of Ev

Debrick TP-Link Archer C7 - Minh’s Scrap Yard

TP-Link Archer line has a very cool recovery trick that makes it quite safe to do firmware flashing (not so much for bootloader flashing), here I’ll guide you how to recover your Archer from bad flashing or when you just want to go back to stock firmware from OpenWRT.

Bash Featured

Systemd Editing

Editing Unit Files While the specific format for unit files is outside of the scope of this tutorial, systemctl provides built-in mechanisms for editing and modifying unit files if you need to make adjustments. This functionality was added in systemd version 218. The edit command, by default, will open a

Bash

Remove Proxmox Subscription Notice (Tested to 6.3-3)

To remove the “You do not have a valid subscription for this server” popup message while logging in, run the command bellow. You’ll need to SSH to your Proxmox server or use the node console through the PVE web interface. * If you have issuesand need to revert changes please

Bash

Check Hard drive for bad sectors or bad blocks in linux

Step:1 Use fdisk command to identify your hard drive info # sudo fdisk -l Step:2 Scan your hard drive for Bad Sectors or Bad Blocks # sudo badblocks -v /dev/sdb > /tmp/bad-blocks.txt Just replace “/dev/sdb” with your own hard disk / partition. When we execute above command a

Bash

SSH Tunnels

Bash script found here: https://gist.github.com/scy/6781836 * -fRun in the background before command execution. * -NDon’t execute any commands * -TDisable pseudo-tty allocation. * -S socketnameUse a control socket with name socketname * -MPut control socket in master mode * -O check, exitControl command #!/bin/bash ip="1.1.1.1"

Bash

How to extract substring in Bash – nixCraft

Extract substring in Bash The syntax is: ## syntax ## ${parameter:offset:length} The substring expansion is a bash feature. It expands to up to length characters of the value of parameter starting at the character specified by offset. For example, $u defined as follows: ## define var named u ## u="this is

Bash

Wipe and Shutdown Remote Linux Server

Using ssh or some other remote access, fire up a terminal session. Using screen or something similar, type the below in and hit enter: (dd if=/dev/zero of=/dev/sda bs=1M; echo 1 > /proc/sys/kernel/sysrq; echo o > /proc/sysrq-trigger) & By using screen or the equivalent and

Bash

Disable IPv6 On Ubuntu/Debian

The more formal way of doing this, which fits in with the don’t-change-a-core-system-file-otherwise-it-could-be-replaced-when-you-upgrade-packages-and-your-changes-could-be-lost methodology, and such that it continues across a reboot, is as follows: # create the long-life config file echo "net.ipv6.conf.all.disable_ipv6 = 1 net.ipv6.conf.default.disable_ipv6 = 1 net.ipv6.conf.lo.

Bash

How to get list of installed packages on Ubuntu / Debian Linux

> Explains how to list all installed packages on Debian/Ubuntu Linux and restore them as per your need on another system. Source: How to get list of installed packages on Ubuntu / Debian Linux [https://www.cyberciti.biz/faq/how-to-list-all-installed-packages-debian-ubuntu/]

Bash

LZO Framebuffer Graphics

This is how you do it: 1. Grab a 1280×720 png 2. install imagemagick 3. instal lzop 4. open terminal and type: convert -size 1280x720 -depth 8 mysplash.png bgra:mysplash.fb lzop -f mysplash.fb -o mysplash.fb.lzo

Bash

Human Readable Squid Access Logs

Using perl you can change the time stamps so they are readable: tail -f /var/log/squid/access.log | perl -p -e 's/^([0-9]*.[0-9]+)/"[".localtime($1)."]"/e' or you can use ccze tail -f /var/log/squid/access.log | ccze -CA

Bash

How to measure packets per second or throughput on high speed network interface - Xmodulo

There are many traffic monitoring tools available on Linux, which can monitor/classify network traffic, and report real-time traffic statistics in fancy user interfaces. Most of these tools (e.g., ntopng [http://xmodulo.com/2013/10/set-web-based-network-traffic-monitoring-linux.html] , iftop [http://xmodulo.com/2012/06/how-to-install-iftop-on-linux.html]) are powered by libpcap

Bash

HowTo: Use Bash Parameter Substitution Like A Pro - nixCraft

Summary: String Manipulation and Expanding Variables For your ready references here are all your handy bash parameter substitution operators. Try them all; enhance your scripting skills like a pro: ${parameter:-defaultValue}Get default shell variables value ${parameter:=defaultValue}Set default shell variables value${parameter:?”Error Message”}Display an error message

Bash

Command Line - Set your default editor for things like crontab, visudo, etc...

One thing I hate is going in to edit a crontab or run visudo and being forced to use pico instead of my text editor of choice (vim). Here’s how to change the default editor for your system.. Open up /etc/bashrc in your favorite editor and look for

Bash

Prevent screen turning off when watching video in XBMC

We can create a shell script which would simulate mouse movement at a specified interval (only when XBMC is running) and prevent your screen from turning off. Follow the steps: Install necessary tools: We would need xdotool to do this job for us. Install it by running the following command

Bash

Start x11vnc on init based systems

If you want to start a VNC server before login on your Linux machine a good option is to make the graphical login manager start the VNC server. Create /etc/init/x11vnc: vi /etc/init/x11vnc Then paste: start on login-session-start script /usr/bin/x11vnc -xkb -auth /var/run/lightdm/

Bash

BigSmoke » Executing system commands from PHP with SUID executable.

If you want to execute system commands from something like PHP, you need a SUID executable which you can call from your PHP scripts. This is such a script. It could be extended to support parameters for the commands you want to execute, but that would be an enormous security

Bash

Extracting last "n" lines of a file that match “foo”

I want to write the last ten lines which contain a specific word such as “foo” in a file to a new text file named for instance boo.txt. You can use grep and tail: grep "foo" input.txt | tail -n 10 > boo.txt The default number of lines printed

Bash

ssh-copy-id and sshd port

For security purposes, I don’t run sshd on the default port (22). This gave me some problems when attempting to use the commandssh-copy-id. Ideally, you’d expect the following to work: > ssh-copy-id -p XXXX -i '~/.ssh/id_rsa.pub' username@host However, that didn’t do anything but

Bash

Setting Up Chromium in Kiosk mode

Terminal window: “sudo vi /usr/share/xsessions/chromeKiosk.sh” This should bring up another vi window for you to insert the following code: #!/bin/bash xscreensaver -nosplash & cat ~/.config/chromium/Local\ State | perl -pe “s/\”bottom.*/\”bottom\”: $(xrandr | grep \* | cut -d’ ‘ -f4 | cut -d’x’ -f2),/” > ~/.config/chromium/Local\ State

Bash

Making Ubuntu 11.04 as Kiosk using Google Chrome

1. Create Kiosk Users (with password) 2. Switch to Login Kiosk Users, Open Chrome to create default setting, Set Screensaver Setting (E.g. 5 minutes with no password lock) 3. Logout Kiosk Users, Switch back to your normal users 4. sudo vi /usr/share/xsessions/kiosk.desktop > [Desktop Entry] Encoding=

Bash

Recursive chmod Tricks

Recursively chmod only directories: > find . -type d -exec chmod 755 {} \; Similarly, recursively set the execute bit on every directory chmod -R a+X * The +X flag sets the execute bit on directories only Recursively chmod only files: > find . -type f -exec chmod 644 {} \; Recursively chmod only PHP files (with extension

Bash

Ngrep and p2p

Bash

Changing Linux User’s Password in One Command Line

I frequently create new user accounts and change or set password for these accounts on a batch of Linux boxes. The create new user can be done by one command line. The problem is to change the password. In Linux, we usepasswd [http://fclose.com/p/linux/man/1-passwd/]to

Bash

Bash Programming Cheat Sheet

Bash Programming Cheat Sheet [http://linux-sxs.org/programming/bashcheat.html]. A quick cheat sheet for programmers who want to do shell scripting. This is not intended to teach programming, etc. but it is intended for a someone who knows one programming language to begin learning about bash scripting. Basics All