Interesting! Indeed, Greg's BashFAQ notes it too: https://mywiki.wooledge.org/BashFAQ/024 https://mywiki.wooledge.org/BashFAQ/024 >Different shells exhibit dif

Interesting! Indeed, Greg's BashFAQ notes it too: https://mywiki.wooledge.org/BashFAQ/024 https://mywiki.wooledge.org/BashFAQ/024 >Different shells exhibit different behaviors in this situation: >- BourneShell creates a subshell when the input or output of anything (loops, case etc..) but a simple command is redirected, either by using a pipeline or by a redirection operator ('<', '>'). >- BASH, Yash and PDKsh-derived shells create a new process only if the loop is part of a pipeline. >- KornShell and Zsh creates it only if the loop is part of a pipeline, but not if the loop is the last part of it. The read example above actually works in ksh88, ksh93, zsh! (but not MKsh or other PDKsh-derived shells) >- POSIX specifies the bash behaviour, but as an extension allows any or all of the parts of the pipeline to run without a subshell (thus permitting the KornShell behaviour, as well).