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 !

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 ?

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Aliases allow a string to be substituted for a word when it is used as the first word of a simple command. The shell maintains a list of aliases that may be set and unset with the alias and unalias builtin commands.

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