Add Current PATH to crontab

Add Current PATH to crontab

Are you sick of your cron job failing because you are not explicitly listing the full path of everything in your shell script? Here’s how to fix it!

Problem

Your script works when you run it from the console but fails in cron.

Cause

Your crontab doesn’t have the right . . . → Read More: Add Current PATH to crontab

self deleting bash script

How to create a bash script that deletes itself

This script will delete itself via the shred command (secure deletion) when it exits

#!/bin/bash # # Author: Steve Stonebraker # Date: August 20, 2013 # Name: shred_self.sh # Purpose: securely self-deleting shell script # http://brakertech.com/self-deleting-bash-script currentscript=$0 # function that is called when the script exits . . . → Read More: self deleting bash script

Howto Add Hex Numbers via Command Line

Recently I needed to calculate the starting and ending memory addresses of an IOS application (in order to dump it). As a result i needed to figure out how to add two hex addresses. Here’s what I discovered.

Basic Example

In this case we are adding 0x4f000 and 0×2000

$ printf “0x%X\n” $(( 0x4f000+0×2000 )) . . . → Read More: Howto Add Hex Numbers via Command Line

Bash Cheat Sheet

Here’s my bash cheat sheet:

Tests Combining [ condition ] && action; # action executes if condition is true. [ condition ] || action; # action executes if condition is false. Filesystem related tests

We can test different filesystem related attributes using different condition flags as follows:

[ -f $file_var ]: Returns true if the . . . → Read More: Bash Cheat Sheet

Whitelist Entire Country with ipset

Goal: Whitelist an Entire Country with ipset For this article i’ll be referencing the github repository I set up at

https://github.com/ssstonebraker/braker-scripts/tree/master/working-scripts/ipset We have a few files there, specifically: * cidr_to_ipset.sh (a script to create an ipset ruleset) * Some example CIDR blocks for Italy (IT.txt), Spain (ES.txt), Great Britian (GB.txt), USA (US.TXT) * sample_firewall.txt (example . . . → Read More: Whitelist Entire Country with ipset

passing bash variable to perl command in bash script

Recently I tried passing a bash variable to perl command in bash script, it didn’t end well.

Troy Engel from http://tacticalvim.wordpress.com/ was nice enough to point out the issue:

use sed instead of perl for what you need; it’s simpler, faster and uses the bash variables easily.

I set up a test script /home/someuser/test.sh to show:

. . . → Read More: passing bash variable to perl command in bash script

sed delete all lines after

Objective: Prep dev httpd.conf for production

Tasks:

Remove jenkins virtual host entry (which starts with a comment line “#Start Jenkins”) Replace .dev with nothing (ex: www.dev.example.com becomes www.example.com) Replace debug with error (ex: Loglevel debug becomes Loglevel error) Sed to remove lines after match

In this example we will use sed delete all lines after . . . → Read More: sed delete all lines after

redhat add multiple users

useradd script

to add multiple users to a system and force them to change their password upon login try the following script:

Redhat # for name in someuser anotheruser yetanotheruser; do useradd $name; echo ‘password’ | passwd –stdin $name; chage -d 0 $name; done

The above script will add three users to the system (someuser . . . → Read More: redhat add multiple users

Bash Server Backup Script

I’ve created a Bash Server Backup Script that will backup your MySQL databases (each database separately in to .sql and .xml files) and your main directories (/var/log, /var/www/html, /etc, /home, /root) to a timestamped directory. Feel free to re-use or hack up however you’d like

Here’s my Bash Server Backup Script: Download the script here

. . . → Read More: Bash Server Backup Script