clean up

_stderr

@@ -1,3 +1,3 @@
 DETECTED0: [This is stderr
-./useless.sh: line 9: command_not_found: command not found]
-ON_EXIT2 127
+./useless.sh: line 7: nope: unbound variable]
+EXIT 1

_stdout

@@ -1,3 +1,2 @@
 stdout A
 stdout B
-stdout C

stderr

@@ -1,2 +1,2 @@
 This is stderr
-./useless.sh: line 9: command_not_found: command not found
+./useless.sh: line 7: nope: unbound variable

test8.sh

@@ -1,34 +1,26 @@
 #!/bin/bash
 
-function on_exit {
+function exit {
   code=${1:-0}
-  # exec 3>&1 1>&2 2>&3
-  # exec 1>&- 3>&- 2>&-
-  # exec 2> >(tee /dev/stderr)
   trap - ERR TERM INT EXIT
-  # exec 2>&-
-  # exec 1> >(tee -ap /dev/stdout) 2>&- 3> >(tee -ap /dev/stderr)
-  # exec 2>&- 3>&-
-  # echo CLOSE OPEN PIPE suite
+
+  # a bit of magic: read content of file still on write!
   count=$(wc -c stderr | cut -d' ' -f1)
   content=$(head -qc$count stderr)
   >&4 echo "DETECTED0: [$content]"
-  >&4 echo ON_EXIT2 ${code}
+
+  >&4 echo EXIT ${code}
 }
 
 set -TEue -o pipefail
-trap 'on_exit $?' ERR TERM INT EXIT
-# exec 2>stderr 3> >(tee -ap /dev/stderr)
+trap 'exit $?' ERR TERM INT EXIT
 [[ -f stderr ]] && rm stderr
-# exec 1> >(tee -p /dev/stdout) 2> >(tee stderr | tee -p /dev/stderr) 3> >(tee -p /dev/stderr)
-# exec 2> >(tee stderr | tee -p /dev/stderr) # 3> >(tee -p /dev/stderr)
-# exec 3> >(tee stderr | tee -p /dev/stderr) 2>&3
-# exec 3> >(tee stderr) 2>&3-
-# exec 2> >(tee stderr)
+export -f exit
+
+# magic FD
 exec 3>stderr 4>/dev/stderr
 source ./useless.sh 2>&3
 exec 3>&- 4>&-
->&2 cat stderr
+
 trap - ERR TERM INT EXIT
-echo --END1
->&2 echo --END2
+[[ -s stderr ]] && >&2 cat stderr

useless.sh

@@ -4,7 +4,7 @@ echo "stdout A"
 # echo toto >>/tmp/toto
 >&2 echo "This is stderr"
 echo "stdout B"
-# $nope
+$nope
 echo "stdout C"
-command_not_found
+# command_not_found
 echo END of useless