Place the below lines near the top of the script.
Call debuggerIt in the script from a point where debugging should take place or at the start of the script execution.
OUTBASE="/tmp/${USER}/${0##*/}.log"
#-------------------------------------------
debuggerIt()
{
test -d ${OUTBASE} || mkdir -p ${OUTBASE}
exec 5> ${OUTBASE}/${0##*/}.debug
BASH_XTRACEFD="5"
PS4='$LINENO: '
set -x
}
#-------------------------------------------
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more functions
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.
start of execution.
debuggerIt
more commands
