Bash: log stdout and stderr while preserving order and provenance

Question

It\'s fairly simple to log both the stdout and the stderr of a command to a log file:

./foo.sh &> log.txt

The problem is that when i

Answer 1

maybe you are looking for script it records both stdout, stderr and the commands...it starts a new shell in which it records everything (or use -c _cmd_)

 $ script tx1

your color() function breaks order because sed is buffering...

Answer 2

How about redirecting stderr to ./tmperr and stdout to ./tmpout, now run two scripts in the background that each continuously read a single line from tmperr or tmpout and then remove that line? This is obviously less than ideal, but if there is a decent delay in the actual foo.sh script, this should work out.