How to implement 'set -o pipefail' in a POSIX way - almost done, expert help needed

Question

I have to implement the BASH set -o pipefail option in a POSIX way so that it works on various LINUX/UNIX flavors. To explain a bit, this option enables the user to

Answer 1

When you type:

run echo "test" ; grep "test" \| awk '{print}'

you invoke run with the arguments echo and "test"; then you invoke grep with arguments "test", |, awk and {print}. Typically, grep is not going to find any of the files called |, awk or {print}.

To invoke run as you wanted, you'd have to escape the semi-colon like you did the | (and you'd need to do things similarly for && or || or & and possibly other components of a command line; the handling of $(...) or backticks `...` needs to be thought about carefully).

If you write:

run echo "test" \; grep "test" \| awk '{print}'

you will at least get all the arguments you intended to run. Whether it then works is debatable; I don't yet understand how the run code you showed is supposed to work.

[...Later...]

It does some fearsome I/O redirections, but wraps each segment of a command separated by a pipe symbol into a separate little packet of hieroglyphs. It assumes that wrapping double quotes around an argument neutralizes it correctly, which is not always true (though it is true a lot of the time).