I think your example is wrong: $ seq 0 5 100000 | parallel touch {}.txt Or you you really want the infinite loop: $ yes | parallel touch '{= $_=seq()*5 =}'.t

I think your example is wrong: $ seq 0 5 100000 | parallel touch {}.txt Or you you really want the infinite loop: $ yes | parallel touch '{= $_=seq()*5 =}'.txt '$' must be quoted $ loop --count-by 5 -- touch '$'COUNT.txt