#!/usr/bin/env bash # Purpose: plain text tar format # Limitations: - only suitable for text files, directories, and symlinks # - stores only filename, content, and mode # - not designed for untrusted input # # Note: must work with bash version 3.2 (macOS) # Copyright 2017 Roger Luethi # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. set -o errexit -o nounset # Sanitize environment (for instance, standard sorting of glob matches) export LC_ALL=C path="" CMD="" ARG_STRING="$*" #------------------------------------------------------------------------------ # Not all sed implementations can work on null bytes. In order to make ttar # work out of the box on macOS, use Python as a stream editor. USE_PYTHON=0 PYTHON_CREATE_FILTER=$(cat << 'PCF' #!/usr/bin/env python import re import sys for line in sys.stdin: line = re.sub(r'EOF', r'\EOF', line) line = re.sub(r'NULLBYTE', r'\NULLBYTE', line) line = re.sub('\x00', r'NULLBYTE', line) sys.stdout.write(line) PCF ) PYTHON_EXTRACT_FILTER=$(cat << 'PEF' #!/usr/bin/env python import re import sys for line in sys.stdin: line = re.sub(r'(?<!\\)NULLBYTE', '\x00', line) line = re.sub(r'\\NULLBYTE', 'NULLBYTE', line) line = re.sub(r'([^\\])EOF', r'\1', line) line = re.sub(r'\\EOF', 'EOF', line) sys.stdout.write(line) PEF ) function test_environment { if [[ "$(echo "a" | sed 's/a/\x0/' | wc -c)" -ne 2 ]]; then echo "WARNING sed unable to handle null bytes, using Python (slow)." if ! which python >/dev/null; then echo "ERROR Python not found. Aborting." exit 2 fi USE_PYTHON=1 fi } #------------------------------------------------------------------------------ function usage { bname=$(basename "$0") cat << USAGE Usage: $bname [-C <DIR>] -c -f <ARCHIVE> <FILE...> (create archive) $bname -t -f <ARCHIVE> (list archive contents) $bname [-C <DIR>] -x -f <ARCHIVE> (extract archive) Options: -C <DIR> (change directory) -v (verbose) --recursive-unlink (recursively delete existing directory if path collides with file or directory to extract) Example: Change to sysfs directory, create ttar file from fixtures directory $bname -C sysfs -c -f sysfs/fixtures.ttar fixtures/ USAGE exit "$1" } function vecho { if [ "${VERBOSE:-}" == "yes" ]; then echo >&7 "$@" fi } function set_cmd { if [ -n "$CMD" ]; then echo "ERROR: more than one command given" echo usage 2 fi CMD=$1 } unset VERBOSE unset RECURSIVE_UNLINK while getopts :cf:-:htxvC: opt; do case $opt in c) set_cmd "create" ;; f) ARCHIVE=$OPTARG ;; h) usage 0 ;; t) set_cmd "list" ;; x) set_cmd "extract" ;; v) VERBOSE=yes exec 7>&1 ;; C) CDIR=$OPTARG ;; -) case $OPTARG in recursive-unlink) RECURSIVE_UNLINK="yes" ;; *) echo -e "Error: invalid option -$OPTARG" echo usage 1 ;; esac ;; *) echo >&2 "ERROR: invalid option -$OPTARG" echo usage 1 ;; esac done # Remove processed options from arguments shift $(( OPTIND - 1 )); if [ "${CMD:-}" == "" ]; then echo >&2 "ERROR: no command given" echo usage 1 elif [ "${ARCHIVE:-}" == "" ]; then echo >&2 "ERROR: no archive name given" echo usage 1 fi function list { local path="" local size=0 local line_no=0 local ttar_file=$1 if [ -n "${2:-}" ]; then echo >&2 "ERROR: too many arguments." echo usage 1 fi if [ ! -e "$ttar_file" ]; then echo >&2 "ERROR: file not found ($ttar_file)" echo usage 1 fi while read -r line; do line_no=$(( line_no + 1 )) if [ $size -gt 0 ]; then size=$(( size - 1 )) continue fi if [[ $line =~ ^Path:\ (.*)$ ]]; then path=${BASH_REMATCH[1]} elif [[ $line =~ ^Lines:\ (.*)$ ]]; then size=${BASH_REMATCH[1]} echo "$path" elif [[ $line =~ ^Directory:\ (.*)$ ]]; then path=${BASH_REMATCH[1]} echo "$path/" elif [[ $line =~ ^SymlinkTo:\ (.*)$ ]]; then echo "$path -> ${BASH_REMATCH[1]}" fi done < "$ttar_file" } function extract { local path="" local size=0 local line_no=0 local ttar_file=$1 if [ -n "${2:-}" ]; then echo >&2 "ERROR: too many arguments." echo usage 1 fi if [ ! -e "$ttar_file" ]; then echo >&2 "ERROR: file not found ($ttar_file)" echo usage 1 fi while IFS= read -r line; do line_no=$(( line_no + 1 )) local eof_without_newline if [ "$size" -gt 0 ]; then if [[ "$line" =~ [^\\]EOF ]]; then # An EOF not preceded by a backslash indicates that the line # does not end with a newline eof_without_newline=1 else eof_without_newline=0 fi # Replace NULLBYTE with null byte if at beginning of line # Replace NULLBYTE with null byte unless preceded by backslash # Remove one backslash in front of NULLBYTE (if any) # Remove EOF unless preceded by backslash # Remove one backslash in front of EOF if [ $USE_PYTHON -eq 1 ]; then echo -n "$line" | python -c "$PYTHON_EXTRACT_FILTER" >> "$path" else # The repeated pattern makes up for sed's lack of negative # lookbehind assertions (for consecutive null bytes). echo -n "$line" | \ sed -e 's/^NULLBYTE/\x0/g; s/\([^\\]\)NULLBYTE/\1\x0/g; s/\([^\\]\)NULLBYTE/\1\x0/g; s/\\NULLBYTE/NULLBYTE/g; s/\([^\\]\)EOF/\1/g; s/\\EOF/EOF/g; ' >> "$path" fi if [[ "$eof_without_newline" -eq 0 ]]; then echo >> "$path" fi size=$(( size - 1 )) continue fi if [[ $line =~ ^Path:\ (.*)$ ]]; then path=${BASH_REMATCH[1]} if [ -L "$path" ]; then rm "$path" elif [ -d "$path" ]; then if [ "${RECURSIVE_UNLINK:-}" == "yes" ]; then rm -r "$path" else # Safe because symlinks to directories are dealt with above rmdir "$path" fi elif [ -e "$path" ]; then rm "$path" fi elif [[ $line =~ ^Lines:\ (.*)$ ]]; then size=${BASH_REMATCH[1]} # Create file even if it is zero-length. touch "$path" vecho " $path" elif [[ $line =~ ^Mode:\ (.*)$ ]]; then mode=${BASH_REMATCH[1]} chmod "$mode" "$path" vecho "$mode" elif [[ $line =~ ^Directory:\ (.*)$ ]]; then path=${BASH_REMATCH[1]} mkdir -p "$path" vecho " $path/" elif [[ $line =~ ^SymlinkTo:\ (.*)$ ]]; then ln -s "${BASH_REMATCH[1]}" "$path" vecho " $path -> ${BASH_REMATCH[1]}" elif [[ $line =~ ^# ]]; then # Ignore comments between files continue else echo >&2 "ERROR: Unknown keyword on line $line_no: $line" exit 1 fi done < "$ttar_file" } function div { echo "# ttar - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -" \ "- - - - - -" } function get_mode { local mfile=$1 if [ -z "${STAT_OPTION:-}" ]; then if stat -c '%a' "$mfile" >/dev/null 2>&1; then # GNU stat STAT_OPTION='-c' STAT_FORMAT='%a' else # BSD stat STAT_OPTION='-f' # Octal output, user/group/other (omit file type, sticky bit) STAT_FORMAT='%OLp' fi fi stat "${STAT_OPTION}" "${STAT_FORMAT}" "$mfile" } function _create { shopt -s nullglob local mode local eof_without_newline while (( "$#" )); do file=$1 if [ -L "$file" ]; then echo "Path: $file" symlinkTo=$(readlink "$file") echo "SymlinkTo: $symlinkTo" vecho " $file -> $symlinkTo" div elif [ -d "$file" ]; then # Strip trailing slash (if there is one) file=${file%/} echo "Directory: $file" mode=$(get_mode "$file") echo "Mode: $mode" vecho "$mode $file/" div # Find all files and dirs, including hidden/dot files for x in "$file/"{*,.[^.]*}; do _create "$x" done elif [ -f "$file" ]; then echo "Path: $file" lines=$(wc -l "$file"|awk '{print $1}') eof_without_newline=0 if [[ "$(wc -c "$file"|awk '{print $1}')" -gt 0 ]] && \ [[ "$(tail -c 1 "$file" | wc -l)" -eq 0 ]]; then eof_without_newline=1 lines=$((lines+1)) fi echo "Lines: $lines" # Add backslash in front of EOF # Add backslash in front of NULLBYTE # Replace null byte with NULLBYTE if [ $USE_PYTHON -eq 1 ]; then < "$file" python -c "$PYTHON_CREATE_FILTER" else < "$file" \ sed 's/EOF/\\EOF/g; s/NULLBYTE/\\NULLBYTE/g; s/\x0/NULLBYTE/g; ' fi if [[ "$eof_without_newline" -eq 1 ]]; then # Finish line with EOF to indicate that the original line did # not end with a linefeed echo "EOF" fi mode=$(get_mode "$file") echo "Mode: $mode" vecho "$mode $file" div else echo >&2 "ERROR: file not found ($file in $(pwd))" exit 2 fi shift done } function create { ttar_file=$1 shift if [ -z "${1:-}" ]; then echo >&2 "ERROR: missing arguments." echo usage 1 fi if [ -e "$ttar_file" ]; then rm "$ttar_file" fi exec > "$ttar_file" echo "# Archive created by ttar $ARG_STRING" _create "$@" } test_environment if [ -n "${CDIR:-}" ]; then if [[ "$ARCHIVE" != /* ]]; then # Relative path: preserve the archive's location before changing # directory ARCHIVE="$(pwd)/$ARCHIVE" fi cd "$CDIR" fi "$CMD" "$ARCHIVE" "$@"