Question

I have a text file that contains protein sequences. I would like to get the total number of residues in each sequence. How can I do this with awk?

>1GS9
PYCPAAVIAPVV
>1LE2
DFEFAKWKN
>1NFN
ADAPPDS

Desired output

1GS9 - 12
1LE2 - 9
1NFN - 7

Answer 1

Read every odd line automatically with { ... } and proteins in even lines with getline:

awk ' {
    getline prot;
    printf "%s - %d\n", substr( $0, 2 ), length( prot ) 
}' infile

Output:

1GS9 - 12
1LE2 - 9
1NFN - 7