Shell Tips !

Some times, while scripting in your favorite shell (I mean Bash !! :) you need to print a sequence of letters or numbers. Don’t write it yourself ! Script it using seq or curly braces !

Print a sequence of number

nicolas@macvin:~$ seq 1 10
1 2 3 4 5 6 7 8 9 10
nicolas@macvin:~$ seq 0 2 10
0 2 4 6 8 10
nicolas@macvin:~$ echo {1..10}
1 2 3 4 5 6 7 8 9 10

Print a sequence of letters

nicolas@macvin:~$ echo {a..g}
a b c d e f g

Hope this will help you while doing a loop or building some hash directories :

nicolas@macvin:~$  mkdir -p test/{1..10}/{1..10}

Enjoy !

Joy ! I just get my new Mac Book Pro (2Go RAM / 2,4Ghz Core 2 Duo / 160Go HDD / etc.). So I’m playing a lot with VMware Fusion and multiple host (debian, ubuntu, solaris, windows, etc.) with a great fluidity ! A big improvement for me who was working with an old DELL Laptop with 1Ghz Celeron and 512Mo of Ram…

But, while playing with my new laptop and my multiple virtual instances I needed to flush my DNS Cache. So, here come the tips :

With Mac OS X <= 10.4 :

macvin:~ root# lookupd -flushcache

With Mac OS X > 10.5 :

macvin:~ root# dscacheutil -flushcache

Here is a quick post about a cheap SAN and secure backup architecture solution for small-sized platform (5/10 servers). In this study case we will see how to use Network Block Devices (nbd) and soft-raid with mdadm. I design it for my personal web platform which is a small one. Last day, I was missing of free space on my backup server and I was angry by the idea to rent a most expensive server to store my backup while I had lot of unused space on my other servers.

1. Initial platform
2. New platform
3. How to do it ?

Read the rest of this entry »