Initial file structrue and rdlink with essential content

rdlink.sh

@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+
+## rdlink [-d|--debug] <PATH>
+##
+## License: GNU GPL V3 or later
+##  Author: Martin Winkler
+
+# Exit on error. Append "|| true" if you expect an error.
+set -o errexit
+# Exit on error inside any functions or subshells.
+set -o errtrace
+# Do not allow use of undefined vars. Use ${VAR:-} to use an undefined VAR
+set -o nounset
+# Catch the error in case mysqldump fails (but gzip succeeds) in `mysqldump |gzip`
+set -o pipefail
+
+LOG_LEVEL="${LOG_LEVEL:-1}" # 7 = debug -> 0 = emergency
+
+rl::rdlink() {
+  local normalized=
+  info "Processing... $@"
+  normalized="$(rl::normalize "${1:-}")"
+  rl::quicklink "${normalized}"
+}
+
+rl::canon() {
+  info "Canonicalize path... $@"
+}
+
+rl::quicklink() {
+  info "Quick rdlink... ${1:-}"
+  readlink "${1:-}" || printf "${1:-}\n"
+}
+
+rl::normalize() {
+  info "Normalizing... ${1:-}"
+  printf "${1:-}\n"
+}
+
+rl::main() {
+  local file=
+  local arg=
+
+  for arg in "$@"; do
+    case "$arg" in
+      --)
+        shift
+        break ;;
+      -d|--debug)
+        shift
+        LOG_LEVEL=7 ;;
+      -dd)
+        shift
+        set -o xtrace ;;
+      -*)
+        shift ;;
+    esac
+  done
+
+  info "BASH rdlink"
+
+  for file in "$@"; do
+    rl::rdlink "$file"
+  done
+}
+
+function rl::log () {
+  local log_level="${1:-${LOG_LEVEL}}"
+  shift
+
+  # all remaining arguments are to be printed
+  local log_line=""
+
+  while IFS=$'\n' read -r log_line; do
+    printf "%s [%9s] %s\n" "$(date -u +"%Y-%m-%d %H:%M:%S UTC")" "${log_level}" "${log_line}" 1>&2
+  done <<< "${@:-}"
+}
+emergency () {                                  rl::log emergency "${@}"; exit 1; }
+alarm()      { [[ "${LOG_LEVEL:-0}" -ge 1 ]] && rl::log alert "${@}"; true; }
+critical ()  { [[ "${LOG_LEVEL:-0}" -ge 2 ]] && rl::log critical "${@}"; true; }
+error ()     { [[ "${LOG_LEVEL:-0}" -ge 3 ]] && rl::log error "${@}"; true; }
+warning ()   { [[ "${LOG_LEVEL:-0}" -ge 4 ]] && rl::log warning "${@}"; true; }
+notice ()    { [[ "${LOG_LEVEL:-0}" -ge 5 ]] && rl::log notice "${@}"; true; }
+info ()      { [[ "${LOG_LEVEL:-0}" -ge 6 ]] && rl::log info "${@}"; true; }
+debug ()     { [[ "${LOG_LEVEL:-0}" -ge 7 ]] && rl::log debug "${@}"; true; }
+msg ()       {                                  echo "$@"; true; }
+
+
+# Provide as function to be called when sourced
+rdlink() {
+  rl::main "$@"
+}
+
+### Check if script is _sourced
+### https://stackoverflow.com/a/28776166
+_sourced=0
+if [ -n "${ZSH_EVAL_CONTEXT:-}" ]; then
+  case ${ZSH_EVAL_CONTEXT:-} in *:file) _sourced=1;; esac
+elif [ -n "${KSH_VERSION:-}" ]; then
+  [ "$(cd $(dirname -- $0) && pwd -P)/$(basename -- $0)" != "$(cd $(dirname -- ${.sh.file}) && pwd -P)/$(basename -- ${.sh.file})" ] && _sourced=1
+elif [ -n "${BASH_VERSION:-}" ]; then
+  (return 0 2>/dev/null) && _sourced=1
+else # All other shells: examine $0 for known shell binary filenames
+  # Detects `sh` and `dash`; add additional shell filenames as needed.
+  case ${0##*/} in sh|dash) _sourced=1;; esac
+fi
+###
+
+if (( ! _sourced )); then
+  rl::main "$@"
+fi
+