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|
#! @BASH@
set -e
# Copyright (C) 2006 Steve Langasek <vorlon@debian.org>
# Copyright (C) 2011 Jean Delvare <jdelvare@suse.de>
# Loosely based on C implementation by Andreas Gruenbacher <agruen@suse.de>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 dated June, 1991.
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
# MA 02110-1301, USA.
usage () {
echo "Usage: $0 -B prefix {-b|-r|-c|-x|-L} [-s] [-k] [-t] [-L] {-f {file|-}|-|file ...}
Create or restore backup copies of a list of files.
Mandatory parameters:
-B Path name prefix for backup files
Action parameters:
-b Create backup (preserve links)
-r Restore the backup
-c Create simple copy
-x Remove backup files and empty parent directories
-L Ensure that source files have a link count of 1
Common options:
-s Silent operation; only print error messages
Restore options:
-k Keep backup files
-t Touch original files after restore (update their mtimes)
-L Ensure that source files have a link count of 1
Backup options:
-L Ensure that source files have a link count of 1
File list parameters:
-f Read the filenames to process from file (- = standard input)
- Read the filenames to process from backup
"
}
: ${QUILT_DIR=@QUILT_DIR@}
. $QUILT_DIR/scripts/utilfns
ensure_nolinks() {
local filename=$1
local link_count tmpname
link_count=$(stat @STAT_HARDLINK@ "$filename")
if [ $link_count -gt 1 ]; then
tmpname=$(mktemp "$filename.XXXXXX")
cp -p "$filename" "$tmpname"
mv "$tmpname" "$filename"
fi
}
backup() {
local file=$1
local backup=$OPT_PREFIX$file
local dir
dir=$(dirname "$backup")
[ -d "$dir" ] || mkdir -p "$dir"
if [ -e "$file" ]; then
$ECHO "Copying $file"
if [ -n "$OPT_NOLINKS" -a "$(stat @STAT_HARDLINK@ "$file")" = 1 ]; then
cp -p "$file" "$backup"
else
ln "$file" "$backup" 2> /dev/null || cp -p "$file" "$backup"
if [ -n "$OPT_NOLINKS" ]; then
ensure_nolinks "$file"
fi
fi
else
$ECHO "New file $file"
: > "$backup"
fi
}
restore()
{
local file=$1
local backup=$OPT_PREFIX$file
if [ ! -e "$backup" ]; then
return 1
fi
if [ -s "$backup" ]; then
$ECHO "Restoring $file"
if [ -e "$file" ]; then
rm "$file"
else
mkdir -p "$(dirname "$file")"
fi
if [ -n "$OPT_NOLINKS" ]; then
cp -p "$backup" "$file"
else
ln "$backup" "$file" 2> /dev/null || cp -p "$backup" "$file"
fi
if [ -n "$OPT_TOUCH" ]; then
touch "$file"
fi
else
$ECHO "Removing $file"
if [ -e "$file" ]; then
rm "$file"
fi
fi
if [ -z "$OPT_KEEP_BACKUP" ]; then
rm "$backup"
rmdir -p "${backup%/*}" 2> /dev/null || true
fi
}
restore_all()
{
local EMPTY_FILES NONEMPTY_FILES
# Store the list of files to process
EMPTY_FILES=$(gen_tempfile)
NONEMPTY_FILES=$(gen_tempfile)
trap "rm -f \"$EMPTY_FILES\" \"$NONEMPTY_FILES\"" EXIT
cd "$OPT_PREFIX"
find . -type f -size 0 -print0 > "$EMPTY_FILES"
find . -type f -size +0 -print0 > "$NONEMPTY_FILES"
cd "$OLDPWD"
if [ -s "$EMPTY_FILES" ]; then
xargs -0 rm -f < "$EMPTY_FILES"
while read -d $'\0' -r
do
$ECHO "Removing ${REPLY#./}"
done < "$EMPTY_FILES"
fi
if [ -s "$NONEMPTY_FILES" ]; then
# Try a mass link (or copy) first, as it is much faster.
# It is however not portable and may thus fail. If it fails,
# fallback to per-file processing, which always works.
local target_dir=$PWD opt_l=-l
[ -n "$OPT_NOLINKS" ] && opt_l=-p
if (cd "$OPT_PREFIX" && \
xargs -0 cp $opt_l --parents --remove-destination \
--target-directory="$target_dir" \
< "$NONEMPTY_FILES" 2> /dev/null); then
while read -d $'\0' -r
do
$ECHO "Restoring ${REPLY#./}"
done < "$NONEMPTY_FILES"
else
(cd "$OPT_PREFIX" && find . -type d -print0) \
| xargs -0 mkdir -p
xargs -0 rm -f < "$NONEMPTY_FILES"
while read -d $'\0' -r
do
local file=${REPLY#./}
local backup=$OPT_PREFIX$file
$ECHO "Restoring $file"
if [ -n "$OPT_NOLINKS" ]; then
cp -p "$backup" "$file"
else
ln "$backup" "$file" 2> /dev/null || cp -p "$backup" "$file"
fi
done < "$NONEMPTY_FILES"
fi
if [ -n "$OPT_TOUCH" ]; then
xargs -0 touch -c < "$NONEMPTY_FILES"
fi
fi
if [ -z "$OPT_KEEP_BACKUP" ]; then
rm -rf "$OPT_PREFIX"
fi
}
remove()
{
local file=$1
local backup=$OPT_PREFIX$file
if [ -e "$backup" ]; then
rm "$backup"
fi
rmdir -p "${backup%/*}" 2> /dev/null || true
}
noop_nolinks()
{
local file=$1
if [ -e "$file" ]; then
ensure_nolinks "$file"
fi
}
copy()
{
local file=$1
local backup=$OPT_PREFIX$file
local dir
dir=$(dirname "$backup")
[ -d "$dir" ] || mkdir -p "$dir"
if [ -e "$file" ]; then
$ECHO "Copying $file"
cp -p "$file" "$backup"
else
$ECHO "New file $file"
: > "$backup"
fi
}
copy_many()
{
local NONEMPTY_FILES
# Store the list of non-empty files to process
NONEMPTY_FILES=$(gen_tempfile)
trap "rm -f \"$NONEMPTY_FILES\"" EXIT
# Keep the temporary file opened to speed up the loop
exec 3> "$NONEMPTY_FILES"
cat "$OPT_FILE" \
| while read
do
if [ -e "$REPLY" ]; then
printf '%s\0' "$REPLY" >&3
else
# This is a rare case, not worth optimizing
copy "$REPLY"
fi
done
exec 3>&-
if [ -s "$NONEMPTY_FILES" ]; then
# Try a mass copy first, as it is much faster.
# It is however not portable and may thus fail. If it fails,
# fallback to per-file processing, which always works.
if xargs -0 cp -p --parents --target-directory="$OPT_PREFIX" \
< "$NONEMPTY_FILES" 2> /dev/null; then
while read -d $'\0' -r
do
$ECHO "Copying $REPLY"
done < "$NONEMPTY_FILES"
else
while read -d $'\0' -r
do
copy "$REPLY"
done < "$NONEMPTY_FILES"
fi
fi
}
# Test if some backed up files have a link count greater than 1
some_files_have_links()
{
(cd "$OPT_PREFIX" && find . -type f -print0) \
| xargs -0 stat @STAT_HARDLINK@ 2> /dev/null | grep -qv '^1$'
}
ECHO=echo
while [ $# -gt 0 ]; do
case $1 in
-b) OPT_WHAT=backup
;;
-r) OPT_WHAT=restore
;;
-c) OPT_WHAT=copy
;;
-x) OPT_WHAT=remove
;;
-B) OPT_PREFIX=$2
shift
;;
-f) OPT_FILE=$2
shift
;;
-s) ECHO=:
;;
-k) OPT_KEEP_BACKUP=1
;;
-L) OPT_NOLINKS=1
;;
-t) OPT_TOUCH=1
;;
-?*) usage
exit 0
;;
*) break
;;
esac
shift
done
if [ -z "$OPT_PREFIX" ]; then
usage
exit 1
fi
if [ "${OPT_PREFIX:(-1)}" != / ]; then
echo "Prefix must be a directory" >&2
exit 1
fi
if [ -z "$OPT_WHAT" ]; then
if [ -n "$OPT_NOLINKS" ]; then
OPT_WHAT=noop_nolinks
else
echo "Please specify an action" >&2
exit 1
fi
fi
if [ -n "$OPT_FILE" ]; then
if [ "$OPT_WHAT" = copy ]; then
copy_many
exit
fi
cat "$OPT_FILE" \
| while read nextfile; do
$OPT_WHAT "$nextfile"
done
exit
fi
if [ "$1" = - ]; then
# No backup directory? We're done
[ -d "$OPT_PREFIX" ] || exit 0
if [ "$OPT_WHAT" = restore ]; then
restore_all
exit
fi
# We typically expect the link count of backed up files to be 1
# already, so check quickly that this is the case, and only if not,
# take the slow path and walk the file list in search of files to fix.
if [ "$OPT_WHAT" = noop_nolinks ] && ! some_files_have_links; then
exit
fi
find "$OPT_PREFIX" -type f -print \
| while read
do
$OPT_WHAT "${REPLY#$OPT_PREFIX}"
done
if [ ${PIPESTATUS[0]} != 0 ]; then
exit 1
fi
exit
fi
while [ $# -gt 0 ]; do
$OPT_WHAT "$1"
shift
done
|