Xensoft

Testing Syntax Highlighting

echo testing 1 2 3

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Print BASH Array Elements on Separate Lines

Very easy and usually accomplished with a loop: $ array=(red green blue) $ for I in ${array[@]}; do echo $I; done red green blue But we can do better!: $ printf '%s\n' "${array[@]}" or: $ ( IFS=$'\n'; echo "${array[*]}" ) Note the switch to "${array[*]}"

Git

A Colorful Condensed git log

Out of the box git commit logs are a bit drab. commit f93f639563850136a11c4cbc39a119c6905feaf2 Author: John Westlund <email@addr> Date: Mon Dec 12 15:49:17 2016 -0800 broke some stuff commit 7dc383f214dd9155d78e4542a993607ec07eaa84 Author: Other Dev <email2@addr> Date: Mon Dec 12 15:26:16 2016 -0800

Change a Repository Name in github

Go to the project in question an open the " Settings" page. Change the Repository name and click on the Rename button. Github will present you with a warning dialog. If you're renaming a repository that multiple people use you'll want to make sure you've given them a heads

Redirect or Pipe Output from One Command to Many

There are a few possible solutions that range from pretty straight forward to a little tricky. Process Substitution If you know you'll always be running under a shell that supports process substitution(bash, zsh, ksh93) multiplexing a command's output is pretty easy using tee. tee supports outputting to multiple "

Add syntax highlighting when pasting code into Outlook 2013

Full credit goes to avbrand.com this technique. I've made some minor tweaks so it will work if you system is configured with a proxy. Remember you're using a web service (https://tohtml.com) to perform the highlighting -- so if the code is really sensitive this may not be

Bash

See 'return codes' from Commands Inside a Chain of Pipes (pipeline)

It can be hard to tell if everything went okay inside a chain of pipes since $? will only report the return code from the final command in the chain. Using a different variable ($PIPESTATUS) the return codes of all the commands chained together can be found. #!/bin/bash # as long

Bash

Track BASH script command failures or abort after N failures

Using the trap built-in signals received by a scripts (e.g. SIGINT). Using this functionality a script can also take actions based on errors. This can allow some more nuanced handling as opposed to set -e. #!/bin/bash ErrorThreshold=5 Cumulative_RC=0 ErrorCount=0 TrackErrorTrap() { ((Cumulative_RC += $?)) ((ErrorCount++)) if

CLI

Use sed to Insert Text Every 'n' Lines/Characters

There are a lot of overly complicated ways to insert a line after every nth line, but the simplest way I find is the following: sed '0~3 s/$/\nMy Text/g' < input.file In a file with six lines you get something like the following: Line 1 Line

AWS

Simple Free-Tier AWS EC2 Instance Setup

This is the first of a few articles detailing how to host multiple Node.js or PHP websites on a single EC2 instance. Log in to AWS, and click on EC2 Click on Launch Instance under Create Instance Select the underlying OS you'd like to use. I've chosen Amazon Linux

AWS

Convert an AWS instance-store AMI to an EBS backed AMI

Borrowed this from a site I had to pull up via Google's cache with some additions. I recently needed to convert an AWS instance-store AMI to an EBS backed AMI. Here’s the steps I took in order to fix that. It’s a ext3 file system in this example,

CLI

Check out a _link from OBS

If you're looking to edit the _link file stored in the repository underlying your OBS you can check it out with the --unexpand-link option. Otherwise you'll end up with the _service file: osc checkout --unexpand-link <Project> <Package> # or if you're already in the project's directory: osc

CLI

Always Display Filename with grep

The easiest way to accomplish this is if you have a relatively recent GNU version of grep. Then the -H version is available to you: printf "This\nis\a\ntest" > /tmp/grep.test grep -H 'is' /tmp/grep.test /tmp/grep.test:This /tmp/grep.test:is

SSH

Add/Remove Passphrase from Existing Private Key

If you've got a private key you're fond of that either has or lacks a passphrase(password) and you'd like to add (because you'd like to put it someplace you trust slightly less) or remove (because you're moving it someplace you trust more [really?]) it's really straight forward. To add

CLI

Best Way to Copy Dotfiles

I've seen a lot of convoluted solutions floating around regarding how to copy files starting with .. The problem everyone is trying to avoid is that when you run something like: cp -r A/.* B/ The above command starts copying everything the entire "A" directory (.) and then from the

E-Mail

sSMTP Certificate Fix for "send-mail: Cannot open smtp.gmail.com:587"

If your sSMTP is configured to use gmail is giving you the following error: send-mail: Cannot open smtp.gmail.com:587 and in /var/log/maillog you see: sSMTP: SSL not working: certificate verify failed (20) sSMTP: Cannot open smtp.gmail.com:587 adding below line to /etc/ssmtp/ssmtp.

CLI

Become an SSH Ninja: SSH Tips and Tricks

OpenSSH has some pretty cool tricks up its sleeve beyond it's "Clark Kent"-esque ability to provide a secure command line interface on a remote system. Here are some of its more "Superman"-type abilities: Public-Key Authentication Learn to Love Your .ssh/config Agent Forwarding Sharing

E-Mail

Make sSMTP Non-Blocking for PHP

If you're trying to send e-mail from PHP (in Drupal or not) using sSMTP you'll find any page sending an e-mail out stalling for several seconds while sSMTP logs in and sends the e-mail out. It's a serious performance hit and can make using your website rather annoying. If you're

CLI

Redirect Output of an Already Running Process

Have you ever started a long running command and then wanted to put it in the background but it's sending its output to STDOUT? Here's a script that uses gdb to swap a processes file descriptors so you can send all that output to a file, or /dev/null after

CLI

Use Redirection Instead of Temp Files

There are certain commands that really want to read input in from a file, like diff. However, if what you're trying to manipulate or use with one of these commands is actually output from another command usually you'd have to write this information out to a file before reading it

Apache

Use Apache as a Reverse Proxy to another Service

If you've got another web application running on your server, but still want it served up on port 80 or 443 you can use Apache's mod_proxy to forward traffic from Apache to your application. An example would be if your web application is running on http://localhost:8080 you

Backups

NetBackup Windows to Linux Restore: Delete the First N Bytes from a File

In my quest to restore some binaries from a Windows client to a Linux client (an unsupported operation) with NetBackup I had to trim off a 240 byte header from each file to get back the binaries that I had backed up. The easiest way to accomplish this was using

Off Topic

Clusters and Spaceships: Made by the Lowest Bidder

<img src="http://ws-na.amazon-adsystem.com/widgets/q?_encoding=UTF8&ASIN=B000FC0O7M&Format=SL250&ID=AsinImage&MarketPlace=US&ServiceVersion=20070822&WS=1&tag=xen02-20" style="all: initial;float: right; margin-left: 5px; margin-right: 5px;" ><img src="

Apache

Redirect Web Traffic to Another Sub-domain (e.g. www) or HTTP to HTTPS

Using the mod_rewrite module you can configure Apache to redirect web traffic from one sub-domain to another. Usually used to redirect a bare domain (http://xensoft.com) to the www sub-domain (http://www.xensoft.com). First make sure you're loading the mod_rewrite module in your httpd.conf or