sudo-ssh-tar

#!/bin/sh
# Copy remote files using ssh, sudo, tar and scp.
# This allows to transfer files from a remote site, where you only have
# sudo access.

# Abort on any non-zero exit status
set -e

: ${VERBOSE:=1}

NAME=$(basename $0)

if [ $# -lt 1 ]; then
	echo "Usage: $NAME <host>:<path> [local path]"
	echo "Default for [local path] is the same name in the current directory."
	exit 1
fi

host="${1%%:*}"
src="${1#*:}"
target="$2"

srcdir="$(dirname "$src")"
srcname="$(basename "$src")"

# Default target: same name in current directory
if [ -z "$target" ]; then
  target="$PWD/$srcname"
fi

[ -n $VERBOSE ] && echo "src: $src\nsrcdir: $srcdir\nsrcname: $srcname\ntarget: $target"

if [ -e "$target" ]; then
  echo "ERROR: $target exists." >&2
  exit 1
fi

# Quote single quotes in arguments:
# source: http://git.kitenet.net/?p=etckeeper.git;a=blob;f=pre-commit.d/30store-metadata;h=aeec37461cd5dc1863b7b58ce722306c7d47c4ae;hb=299dc44f1014404ca1367b72e2a22605ef22d127#l40
shellquote() {
  sed -e "s/'/'\"'\"'/g" -e "s/^/'/" -e "s/$/'/"
}
srcdir=$(echo "$srcdir" | shellquote)
srcname=$(echo "$srcname" | shellquote)

mktemp_template="tmp-$NAME.tar.bz2.XXX"
remote_tempfile=$(ssh "$host" mktemp "\$HOME/$mktemp_template")
local_tempfile=$(mktemp "$PWD/$mktemp_template")
[ -n $VERBOSE ] && echo "remote_tempfile: $remote_tempfile, local_tempfile: ./$local_tempfile"

[ -n $VERBOSE ] && echo "Compressing remotely."
ssh -t $host "sudo tar cjf '$remote_tempfile' -C '$srcdir' '$srcname'"

[ -n $VERBOSE ] && echo "Copying file."
scp "$host:$remote_tempfile" "$local_tempfile"

[ -n $VERBOSE ] && echo "Remove remote temporary file."
ssh "$host" rm "$remote_tempfile"

# To simulate scp's `-p` option (requires sudo):
# tar xf "$local_tempfile" --atime-preserve --preserve-permissions --preserve-order --same-owner
tar xf "$local_tempfile" --atime-preserve