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#!/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=$(cat << 'PEF'
#!/usr/bin/env python
import re
import sys
for line in sys.stdin:
line = re.sub(r'(?/dev/null; then
echo "ERROR Python not found. Aborting."
exit 2
fi
USE_PYTHON=1
fi
}
#------------------------------------------------------------------------------
function usage {
bname=$(basename "$0")
cat << USAGE
Usage: $bname [-C ] -c -f (create archive)
$bname -t -f (list archive contents)
$bname [-C ] -x -f (extract archive)
Options:
-C (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" "$ARCHIVE" "$@"