myshellconfig/logging

#!/bin/bash
#### LOGGING
## from https://www.cubicrace.com/2016/03/log-tracing-mechnism-for-shell-scripts.html
[ -z "${SCRIPT_LOG+x}" ] && export SCRIPT_LOG=${HOME}/logs/scriptlog
mkdir -p "$(dirname ${SCRIPT_LOG})"
touch $SCRIPT_LOG


#for level in emerg alert crit err warning notice info debug; do

loglevels=(debug info notice warning err crit alert emerg)

for level in SCRIPTENTRY SCRIPTEXIT ENTRY EXIT; do
    printf -v functext -- '%s() {
    local loglevels
    declare -a loglevels
    loglevels=(emerg alert crit err warning notice info) 
    timeAndDate=$(date)
    script_name="${BASH_SOURCE[0]##*/}"
    local LOGLEVEL=${LOGLEVEL,,}
    if [[ ! ${loglevels[@]} =~ "${LOGLEVEL:-${LOGLEVEL_DEFAULT,,}}" ]];then
        echo "[%s]  »${script_name}« ######################################################" >&2
    fi
    if [[ ! ${loglevels[*]} =~ "${FILELOGLEVEL:-$FILELOGLEVEL_DEFAULT}" ]];then
        echo "[${timeAndDate}] [%s] ${script_name}" >> "${SCRIPT_LOG}"
    fi }' "${level}" "${level^^}" "${level^^}"
    eval "$functext"
    export -f "${level}"
done

for level in trace debug info notice warning err crit alert emerg; do
    loglevels=( ${loglevels[@]/$level} )
    printf -v functext -- 'log%s() {
    local msg="$@"
    [ -z "${msg:+x}" ] && return 0
    local loglevels
    declare -a loglevels
    loglevels=(%s)
    timeAndDate=$(date)
    script_name="${BASH_SOURCE[0]##*/}"
    local LOGLEVEL=${LOGLEVEL,,}
    if [[ ! ${loglevels[@]} =~ "${LOGLEVEL:-${LOGLEVEL_DEFAULT,,}}" ]];then
        printf  "[%%s] (%%s) %%s\n" %s "${FUNCNAME[1]}" "${msg}" >&2
    fi
    if [[ ! ${loglevels[*]} =~ "${FILELOGLEVEL:-$FILELOGLEVEL_DEFAULT}" ]];then
        printf  "[%%s] [%%s] (%%s) %%s\n" "$timeAndDate" %s "${FUNCNAME[1]}" "${msg}"  >> "${SCRIPT_LOG}"
    fi }' "$level" "$(echo ${loglevels[@]})" "${level^^}" "${level^^}"
    eval "$functext"
    export -f "log${level}"
done