I wrote this program because I needed a fast fasta word counter and the EMBOSS wordcount utility is extremely slow.
zwc is on the order of 10X to 100X faster than EMBOSS' program, depending on the parameters and input data.
Install from github with
library(devtools)
install_github('arendsee/zwc')# Get counts of all 2-mers in a fasta file
fasta_wc("my-fasta-file.fa", k=2)