I have a multigenome vcf file. Suppose the file has samples A to Z, but I want to extract the subset of samples B to G and extract a small vcf file. How can I make such subset  vcf file?
I have created this bash loop to loop over files (by chromosome or any vcf file). Then using vcf-subset tool, I was able to extract the subset file. Here, sample.txt is the list of samples per line. No need to `tabix` or `bgzip` parent vcf files with this method, but is a bit slower.

    for i in /path/dir/*.vcf; do
        vcf-subset -c sample.txt "$i" | bgzip  -c > /get/inthis/dir/output_"${i##*/}"_.vcf.gz
    done