Bash Tidbits

November 23rd, 2012 by Erin Scott

If you’re like me you have a fairly customized shell environment full of aliases, functions and other goodies to assist with the various sysadmin tasks you need to do.  This makes being a sysadmin easy when you’re up and running on your primary machine but what happens when you’re main machine crashes?

Last weekend my laptop started limping through the day and finally dropped dead and I was left with a pile of work yet on my secondary machine.  Little to no customization was present on this machine which made me nearly pull out my hair on more than one occasion.

Below is a list of my personal shell customizations and other goodies that you may find useful to have as well.  This is easily installed into your ~/.bashrc or ~/.bash_profile file to run every time

 

# Useful Variables
export CLICOLOR=1
export LSCOLORS=GxFxCxDxBxegedabagaced
export SN=`netstat -nr| grep -m 1 -iE ‘default|0.0.0.0′ | awk ‘{print \$2}’ | sed ‘s/\.[0-9]*$//’ `
export ph=”phobos.crapnstuff.com”
PS1=’\[\033[0;37m\]\u\[\033[0m\]@\[\033[1;35m\]\h\[\033[0m\]:\[\033[1;36m\]\w\[\033[0m\]\$ ‘# Aliases
alias arin=’whois -h whois.arin.net’
alias grep=’grep –color’
alias locate=’locate -i’
alias ls=’ls -lh’
alias ns=’nslookup’
alias nsmx=’nslookup -q=mx’
alias pg=’ping google.com’
alias ph=’ping phobos.crapnstuff.com’
alias phobos=’ssh -i ~/.ssh/identity -p 2200 -X -C -t alt229@phobos.crapnstuff.com screen -R’
alias pr=’ping `netstat -nr| grep -m 1 -iE ‘\”default|0.0.0.0′\” | awk ‘\”{print $2}’\”`’
alias py=’ping yahoo.com’

At the top of the file you have 2 variables that set nice looking colors in the terminal so make it more readable.

One of my faviourite little shortcuts comes next.  You’ll notice that there is a variable called SN there and it is a shortcut for the subnet that you happen to be on.  I find myself having to do stuff to the various hosts on my subnet so if I can save having to type in 192.168.25 50 times a day then that’s definitely useful.  Here are a few examples of how to use it:

ping $SN.10
nmap -p 80 $SN.*
ssh admin@$SN.40

Also related is the alias named pr.  This finds the router and pings it to make sure it’s up.

Continuing down the list there is the alias ph which goes to my personal server.  Useful for all sorts of shortcuts and can save a fair amount of work.  Examples:

ssh alt229@$ph
scp ./test.txt alt229@$ph:~/

There are a bunch of other useful aliases there too so feel free to poach some of these for your own environment!

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One Response to “Bash Tidbits”

  1. Github or it didn’t happen! Check https://github.com/alt229 for developments!