mk_bb_links.sh (draft #1)

#!/bin/bash
CWD="$PWD"
BB_NAME_TARGET="${1:-busybox}"
BB_NAME_SOURCE="$BB_NAME_TARGET"

CHROOT=no #If chroot=yes then locate full utils using chroot.
#Add_BB_Wrapper=no
USE_BB_FILE_LIST=yes
#USE_BB_FULL_PATH=yes
WRITE_NORMAL_LOCATION=yes #if no then BB links will be written to BB_UTIL_DIR only.
MOVE_BB=no
COPY_BB=yes #Copy takes precedence over move.
CHECK_SOURCE=yes #Don't write sylink location in normal location if it isn't a symlink in the source.
DELETE_SOURCE=no #Delete source file if it is a symlink

#CHROOT_DIR="$CWD/puppy_fossapup64_9.5.sfs.extracted"
TARGET_DIR="$CWD/puppy_fossapup64_9.5_busybox"
SOURCE_DIR="$CWD/puppy_fossapup64_9.5.sfs.extracted"
CHROOT_DIR="$SOURCE_DIR"

mkdir -p "$TARGET_DIR"

BB_UTIL_DIR_rel="${BB_UTIL_DIR_rel:-/bin/bb_utils}"
BB_UTIL_DIR="$TARGET_DIR/${BB_UTIL_DIR_rel:-/bin/bb_utils}"

BB_DIR_rel="${BB_DIR_rel:-/bin}"
BB_TARGET_DIR="$TARGET_DIR${BB_DIR_rel:-/bin}"
#BB_DIR=
BB_SOURCE_DIR="$CHROOT_DIR${BB_DIR_rel:-/bin}"
BB_DIR_CHROOT="$BB_SOURCE_DIR"

BB_TARGET_PATH="$BB_TARGET_DIR/$BB_NAME_TARGET"
BB_SOURCE_PATH="$BB_SOURCE_DIR/$BB_NAME_SOURCE"

BB_LIST_rel=/bin/busybox.lst
BB_LIST="$SOURCE_DIR$BB_LIST_rel"

function mk_parrent_dir(){
  parrent="$(dirname $1)"
  if  [ ${#parrent} -le 1 ]; then
    return 0
  else [ ! -d "$TARGET_DIR$parrent" ];
    if [ ! -z "`which cpio`" ]; then
        ( cd "$SOURCE_DIR"
          echo "./$1" | \
            cpio -pdu "$TARGET_DIR" )
    else
      mkdir -p "$TARGET_DIR/$1"
    fi
  fi
}

if [ ! -e "$BB_TARGET_PATH" ]; then
  if [ "$MOVE_BB" = yes ] && [ "$CHROOT_DIR" != "$SOURCE_DIR" ] && [ "$COPY_BB" != yes ]; then
    mk_parrent_dir "$BB_DIR_rel/$BB_NAME_TARGET"
    mv "$BB_SOURCE_PATH" "$BB_TARGET_PATH"
  elif [ "$MOVE_BB" = yes ] || [ "$COPY_BB" = yes ]; then
    mk_parrent_dir "$BB_DIR_rel/$BB_NAME_TARGET"
    [ ! -e "$BB_TARGET_PATH" ] && cp -a "$BB_SOURCE_PATH" "$BB_TARGET_PATH"
  fi
fi


#BB_PATH_rel=/bin/busybox
#BB_PATH=$CHROOT_DIR/${BB_PATH_rel:-/bin/busybox}





CHROOT_CMD="`which chroot-FULL`"
[ -z "$CHROOT_CMD" ] && CHROOT_CMD="`which chroot`"

function bb_list_full()  { #$1=busybox or busybox-path
   local bb_name="${1:-busybox}"
   if [ ! -z "$BB_LIST" ]; then
     cat "$BB_LIST"
   elif [ ! -z "$CHROOT_DIR" ]; then
     "$CHROOT_CMD" "$CHROOT_DIR" "$bb_name" --list-full || \
     "$CHROOT_CMD" "$CHROOT_DIR" "$BB_DIR_rel/$bb_name" --list-full
   else #Requires static busybox
      "$BB_TARGET_DIR/$bb_name" --list-full
   fi
}
function bb_list()  { #$1=busybox or busybox-path
   local bb_name="${1:-busybox}"
   if [ ! -z "$BB_LIST" ]; then
     cat "$BB_LIST" | sed -r 's@^.*/@@g'
   elif [ ! -z "$CHROOT_DIR" ]; then
     "$CHROOT_CMD" "$CHROOT_DIR" "$bb_name" --list || \
     "$CHROOT_CMD" "$CHROOT_DIR" "$BB_DIR_rel/$bb_name" --list
   else #Requires static busybox
      "$TARGET_DIR$BB_DIR_rel/$bb_name" --list
   fi
}

rp_help_1="$(realpath --help | grep '--relative-to')"
function find_rel_path(){  #source dir, target dir
  if [ ! -z "${#rp_help_1}" ]; then
    find_rel_path_result="$(realpath --relative-to="$1" "$2")"
  else
    find_rel_path_result="$(echo "$1" |  sed -r 's/([^//]*)/../g' )/$2"
  fi
}
find_rel_path "$BB_UTIL_DIR" "$BB_TARGET_DIR"; UTIL_DIR_rel_BB_DIR="$find_rel_path_result"


[ ! -e "$BB_UTIL_DIR" ] && mkdir -p "$BB_UTIL_DIR"

#for aBB_NAME in busybox.nosuid busybox.suid busybox; do
  aBB_NAME=busybox #TODO. let other bb names be used.
  cd "$BB_UTIL_DIR"
  [ ! -e "./$aBB_NAME" ] && continue
  [ $(file --mime-type "$BB_TARGET_DIR/$aBB_NAME" | grep -c text) -gt 0 ] && continue
  #TODO, skip busybox if it is a wrapper script
  #TODO considering adding an EOF at the end of --list to make sure that the read teminates
  bb_list "$aBB_NAME" |
  while read UTIL_NAME; do
       if [ ! -e "$BB_UTIL_DIR/$UTIL_NAME" ] && [ ! -z "$BB_UTIL_DIR" ]; then
         cd "$BB_UTIL_DIR"
         ln -s "$UTIL_DIR_rel_BB_DIR/$aBB_NAME" "$UTIL_NAME"
       fi
       #if [ "$USE_BB_FULL_PATH" = yes ] || [ "$USE_BB_FILE_LIST" = yes ]; then
       if [ "$WRITE_NORMAL_LOCATION" = yes ]; then
         FP="/$(bb_list_full "$aBB_NAME" | grep -E "/$UTIL_NAME"'$' | sed -r 's@^/@@g')"
         if [ "$CHECK_SOURCE" = yes ]; then
           [ ! -L "$SOURCE_DIR$FP" ] && continue
         fi
         cd "$(dirname "$TARGET_DIR$FP")"
         if [ ! -z "$FP" ]; then
           find_rel_path "$TARGET_DIR$(dirname "$FP")" "$BB_TARGET_PATH"; REL_SYM_TO_BB="$find_rel_path_result"
           if [ ! -e "$TARGET_DIR/$aBB_NAME" ]; then
             ln -s "$REL_SYM_TO_BB" "$UTIL_NAME"
           fi
         fi
       fi
  done

if [ "$MOVE_BB" = yes ] && [ -e "$BB_SOURCE_PATH" ]; then
  rm "$BB_SOURCE_PATH"
fi

#done

#if [ Add_BB_Wrapper = yes ] && [ ! -e $BB_DIR/busybox ]; then
#echo "#!/bin/sh
#script=\${0##*/}
#script2=\$1
#if [ \"\$script\" = \"busybox\" ]; then
#  script=\$script2 ; shift
#fi
#exec \"$BB_UTIL_DIR/\$script\" \"\$@\"" > "/$BB_DIR/busybox"
#chmod +x "/$BB_DIR/busybox"
#fi