I had 421 vcf files, I want to convert the all vcf files to the ped file (format of plink),

and I want to merge these 421 ped files to a ped file, what is the best should I do?

Thanks a lot!
using [plink][1]   
in the directory that contains your vcf files run this command  "assuming that plink in the [path][2]" 

    for i in *.vcf;  do f="${i%.*}"; plink --vcf $i --maf 0.05 --recode --out $f".ped";done


example:

    plink --file fA --merge-list allfiles.txt --make-bed --out mynewdata 


  [1]: http://pngu.mgh.harvard.edu/~purcell/plink/
  [2]: http://www.linfo.org/path_env_var.html