UNIX for Dummies Questions & Answers

I have a fasta file that looks like this:

>Noname
ACCAAAATAATTCATGATATACTCAGATCCATCTGAGGGTTTCACCACTTGTAGAGCTAT
CAGAAGAATGTCAATCAACTGTCCGAGAAAAAAGAATCCCAGG
>Noname
ACTATAAACCCTATTTCTCTTTCTAAAAATTGAAATATTAAAGAAACTAGCACTAGCCTG
ACCTTTAGCCAGACTTCTCACTCTTAATGCTGCGGACAAACAGA
...

I want to rename these starting with ">1", going to as many sequences as I have, which is on the order of 10^6.

I hear you can do this through a command line one-liner. A simple script would also be great.

It should be simple, I am just a shameless newbie and am stuck.

Code:

$ awk -F'\n' 'BEGIN { ORS=""; RS=">"; N=-1 ; OFS="\n" } { if(N++ >= 0) { $1=">"N; print $0; } }' < data
>1
ACCAAAATAATTCATGATATACTCAGATCCATCTGAGGGTTTCACCACTTGTAGAGCTAT
CAGAAGAATGTCAATCAACTGTCCGAGAAAAAAGAATCCCAGG
>2
ACTATAAACCCTATTTCTCTTTCTAAAAATTGAAATATTAAAGAAACTAGCACTAGCCTG
ACCTTTAGCCAGACTTCTCACTCTTAATGCTGCGGACAAACAGA

$

try:

Code:

awk '/^>/{$0=">"++i}1'