Could reduce down to ~60 lines (e.g. no comments, header, putting on one line when possible,...)

rdlink.sh

@@ -40,65 +40,25 @@ msg()       {                                  echo "$@"; true; }
 ### Script
 rl::rdlink() {
   local subject=
-  local work=
-
-  info "Processing: $*"
-  info "  with pwd: $(pwd)"
-
-  subject="$(rl::cleanpath "${1:-}")" || true
-
-  # Follow multiple symlinks
-  while subject="$(rl::quicklink "${subject}")" ; do
-    : # A link was resolved at least once
-    info "  rl::rdlink - Link found: $subject"
-  done
-
-  # Special cases handling
-  {
-    # If subject is still a link, after rl::quicklink call(s)
-    # current user has no permission to access the link itself
-    # (e.g. /proc/**/cwd)
-    if [ -L "${subject}" ] ; then
-      info "  rl::rdlink exit - can't access link ${subject}"
-      printf "\n"
-      return 1
-    fi
-  }
-
-  # Empty output if (dirname $subject) is not a valid path
-  if ! work="$(rl::canon "${subject}")" ; then
-    info "  rl::rdlink exit - invalid path ${work}"
-    printf "\n"
-    return 1
-  else
-    subject="${work}"
-  fi
 
+  subject="${1:-}"
+  while [[ "${subject:-}" = *"//"* ]]; do subject="${subject/\/\///}"; done
+  while subject="$(rl::quicklink "${subject}")" ; do : ; done
+  [ -L "${subject}" ] && printf "\n" && return 1
+  subject="$(rl::canon "${subject}")" || { printf "\n"; return 1; }
   printf "%s\n" "${subject}"
 }
 
 rl::quicklink() {
-  subject=
-  work=
+  local subject=
+  local work=
 
-  info "Quicklink... ${1:-}"
-
-  # Check if current candidate is a symlink
-  if ! subject=$(readlink -- "${1:-}"); then
-    printf -- "%s\n" "${1:-}"
-    return 1
-  fi
-  info "  rl::quicklink symlink ${1} -> ${subject}"
-
-  # relative symlink target; prepend its parent direcotry
+  subject=$(readlink -- "${1:-}") || { printf -- "%s\n" "${1:-}"; return 1; }
   if [[ "${subject}" != "/"* ]]; then
     work="$(rl::canon "$(dirname -- "${1:-}")")"
     subject="${work}/${subject}"
-    info "  rl::quicklink relative link resolved: ${subject}"
   fi
-
   printf "%s\n" "${subject}"
-  return 0
 }
 
 rl::canon() {
@@ -110,100 +70,31 @@ rl::canon() {
   local retval=0
 
   start="${1:-}"
-  info "Canonicalize path... ${start}"
-
   while (( run )) ; do
     if work="$(cd "${start}" >/dev/null 2>&1 && pwd -P)" ; then
-      # Special: `pwd -P` returns with // as root for links starting at /
-      # e.g. $(readlink /proc/self/root) == "/"
-      #      $(cd /proc/self/root/mnt && pwd -P) == "//mnt"
-      subject="$(rl::normalize "${work}")"
-      info "  rl::canon valid directory: ${subject}"
-      run=0
+      subject="$(rl::normalize "${work}")"; run=0
     elif work="$(cd "$(dirname -- "${start}")" >/dev/null 2>&1 && pwd -P)" ; then
       bname="$(basename -- "${start}")"
-
-      # Special: / produces //
       [[ "${work}" == "/" ]] && work=
-
       subject="${work}${bname:+"/${bname}"}"
-      info "  rl::canon valid parent: ${subject}"
-
-      # Special: Succeed with valid element after second run; see special below
-      # e.g. /root/.
-      #      * /root is valid but not accessible
-      if (( retval )) && [ -e "${subject}" ] ;then
-        info "  rl::canon valid element"
-        retval=0
-      fi
-      run=0
+      (( retval )) && [ -e "${subject}" ] && retval=0; run=0
     else
-      # Special: Some paths may be resolvable after normalization
-      # e.g. somedir/..
-      #      * base "somedir" does not exist
-      #      * but irrelevant because of /..
-      #      * resolves to pwd but fails by readlink -f
       work="$(rl::normalize "${start}")"
-      if [[ "${work}" != "${start}" ]] ; then
-        info "  rl::canon retry with: ${work}"
-        start="${work}"
-        retval=1
-        continue
-      fi
-      info "  rl::canon invalid path: ${work}"
-      subject="${work}"
-      run=0 && retval=1
+      [[ "${work}" != "${start}" ]] && start="${work}" && retval=1 && continue
+      subject="${work}"; run=0 && retval=1
     fi
   done
-
-  printf -- "%s\n" "${subject}"
-  return ${retval}
-}
-
-rl::cleanpath() {
-  local work=
-  local rex_tmp=
-
-  info "Cleaning path... ${1:-}"
-  work="${1:-}"
-
-  # Remove multiple /
-  while [[ "${work:-}" = *"//"* ]]; do
-    work="${work/\/\///}"
-  done
-
-  info "  rl::cleanpath result: ${work}"
-  printf -- "%s\n" "${work}"
+  printf -- "%s\n" "${subject}"; return ${retval}
 }
 
 rl::normalize() {
   local work=
-
-  info "Normalizing path... ${1:-}"
   work="${1:-}"
 
-  # Remove dir/.. sequences.
-  local rex_tmp='[^/][^/]*/\.\./*'
-  while [[ "${work}" =~ $rex_tmp ]] ; do
-    work="${work/"${BASH_REMATCH[0]}"/}"
-  done
-
-  # Remove /./ and /.$ sequences.
-  rex_tmp='/\.(/|$)'
-  while [[ "$work" =~ $rex_tmp ]]; do
-    work="${work/${BASH_REMATCH[0]}/${BASH_REMATCH[1]/$//}}"
-  done
-
-  # Remove leading ./
+  while [[ "${work}" =~ [^/][^/]*/\.\./* ]] ; do work="${work/"${BASH_REMATCH[0]}"/}"; done
+  while [[ "$work" =~ /\.(/|$) ]]; do work="${work/${BASH_REMATCH[0]}/${BASH_REMATCH[1]/$//}}"; done
   work="${work#./*}"
-
-  # Remove trailing /
-  rex_tmp='(.*[^/])/$'
-  if [[ "${work}" =~ $rex_tmp ]] ; then
-    work="${BASH_REMATCH[1]}"
-  fi
-
-  info "  rl::normalize result: ${work}"
+  [[ "${work}" =~ (.*[^/])/$ ]] && work="${BASH_REMATCH[1]}"
   printf -- "%s\n" "${work}"
 }
 
@@ -213,31 +104,18 @@ rl::main() {
 
   for arg in "$@"; do
     case "$arg" in
-      --)
-        shift
-        break ;;
-      -d|--debug)
-        shift
-        LOG_LEVEL=7 ;;
-      -dd)
-        shift
-        set -o xtrace ;;
-      -*)
-        shift ;;
+      --) 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
+  for file in "$@"; do rl::rdlink "$file"; done
 }
 
 # Provide as function to be called when sourced
-rdlink() {
-  rl::main "$@"
-}
+rdlink() { rl::main "$@"; }
 
 ### Check if script is _sourced
 ### https://stackoverflow.com/a/28776166
@@ -255,9 +133,7 @@ else # All other shells: examine $0 for known shell binary filenames
 fi
 ###
 
-if (( ! _sourced )); then
-  rl::main "$@"
-fi
+(( ! _sourced )) && rl::main "$@"
 
 ### Script EOF