murex breaks POSIX compliance massively because it acts as a proxy between each command in the pipeline. This means it can forward type information to processes within murex (eg builtins) but read and write byte streams to external commands.
As mentioned to one of your other replies, this causes a few issues (eg forking). But processes are still run in parallel like with a traditional shell and 99% of time this massive cheat is transparent to both the running processes and the users too.
This cheat does allow for some additional features though, like
- colourisation of STDERR (so it stands out)
- STDERR byte count used to judge if a process has failed
(possibly a few others I've forgotten but have to dash now for a lockdown Zoom party....sorry)
As mentioned to one of your other replies, this causes a few issues (eg forking). But processes are still run in parallel like with a traditional shell and 99% of time this massive cheat is transparent to both the running processes and the users too.
This cheat does allow for some additional features though, like
- colourisation of STDERR (so it stands out)
- STDERR byte count used to judge if a process has failed
(possibly a few others I've forgotten but have to dash now for a lockdown Zoom party....sorry)