I am trying to save some logs from bash functions which execute tools (some of them run in subshells). In addition I would like to print all errors to the terminal.
My code leads to a sigpipe and exit code 141 upon hitting ctr-c plus a strange log file. The pipe fail seems to be caused by the redirection of stdout to stderr within the trap, which breaks the stdout stream of the tee command. Interestingly the code terminates as expected with exit code 130 without the redirection used in the trap or the cat
command.
I am still unable to fix and explain the resulting log file. Why are there some echos twice and why are the trap echos written to the file as well?
Why isn't the sigpipe caused earlier by the redirection within the function?
trap '
echo trap_stdout
echo trap_stderr >&2
' INT
fun(){
echo fun_stdout
echo fun_stderr >&2
( sleep 10 | cat )
}
echo > log
fun >> log 2> >(tee -a log)
log file
fun_stdout
fun_stderr
fun_stderr
trap_stdout
EDIT: working example according to oguz ismail answer
exec 3>> log
exec 4> >(tee -ai log >&2)
fun 2>&4 >&3
exec 3>&-
exec 4>&-