$ yes | parallel -N0 -j1 echo touch '{= $_=seq()*5 =}'.txt
vs
$ loop --count-by 5 -- touch $COUNT.txt
UNIX is about using the right tool for the right job, not the same tool for every job.
Let us remember the koan:
A Unix novice came to Master Foo and said: “I am confused. Is it not the Unix way that every program should concentrate on one thing and do it well?”
Master Foo nodded.
The novice continued: “Isn't it also the Unix way that the wheel should not be reinvented?”
Master Foo nodded again.
“Why, then, are there several tools with similar capabilities in text processing: sed, awk and Perl? With which one can I best practice the Unix way?”
Master Foo asked the novice: “If you have a text file, what tool would you use to produce a copy with a few words in it replaced by strings of your choosing?”
The novice frowned and said: “Perl's regexps would be excessive for so simple a task. I do not know awk, and I have been writing sed scripts in the last few weeks. As I have some experience with sed, at the moment I would prefer it. But if the job only needed to be done once rather than repeatedly, a text editor would suffice.”
Master Foo nodded and replied: “When you are hungry, eat; when you are thirsty, drink; when you are tired, sleep.”
Upon hearing this, the novice was enlightened.
$ 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
Like... the ability to run things in parallel?
Loop looks nice, don’t get me wrong. I think I’ll try it! It just seems like comparing it to Parallel is misplaced here, and a bad idea in general, since they’re not remotely related. Ole is comparing all these utilities to Parallel to show how general Parallel can be, and suggest you only need his one program and one syntax to emulate hundreds of different utilities: his argument is implicitly that people should use Parallel and not loop.