复制具有空文件的目录树

Question

I am looking to create a copy of a folder tree with empty files in it. The files in the source folders are not empty but I want the files in the destination folders to be empty. (I don't think I can just use soft/hard link because I am on Mac OS X , right?) It's to keep track of the content of many external hard drives with a lot of larges video files in them.

I found rsync -a -f"+ */" -f"- *" source/ destination/ to copy the folders but I didn't find a way to create the empty files (I tried a tcsh foreach but it failed because there are spaces in folders name).

Thanks for your help!

Answer 1

Building on the answer from ursusd8, here's a recursive solution that will work in bash version 4, if you have that installed...

shopt -s globstar
cd /path/to/source/
for f in **/*; do
  mkdir -p "/path/to/target/${f%/*}"   # make the containing directory if required
  touch "/path/to/target/$f"           # make a zero-length file
done

This runs the mkdir command many more times than required, but it's quick. Note that bash 4 may not be available on your system unless you've explicitly installed it using MacPorts or homebrew or the like.

A longer alternative would be to separate the steps of creating your directory tree and touching the files:

cd /path/to/source/
find . -type d -exec mkdir -p /path/to/target/{} \;
find . -type f -exec touch /path/to/target/{} \;

Note that this two-stage find solution uses no bashisms, and can likely be run in any shell.

Answer 2

Here is a solution, which can even handle uncommon filenames correctly (like filenames with a newline inside etc.)

It will first create the directory tree and then create empty files. additional external commands other than find , mkdir and touch are required.

#!/bin/bash

# IMPORTANT: SOURCE and DESTINATION have to be absolute pathes
# To fix the missing parameter -printf of find in mac os x,
# i used a technique to reproduce the functionality.
# But now it IS IMPORTANT that both of these variables contain an absolute path!

SOURCE="/home/you/source_dir/"
DESTINATION="/where/ever/destination_dir/"

#first 'copy' the directory tree
while
    IFS="" read -r -d '' -u 9 dir
do
    #remove the $SOURCE part
    dir="${dir#${SOURCE}}"

    mkdir "${DESTINATION}/${dir}"
done 9< <(find "${SOURCE}" -type d -print0)

#then create empty files inside the new tree
while
    IFS="" read -r -d '' -u 9 file
do
    #remove the $SOURCE part
    file="${file#${SOURCE}}"

    touch "${DESTINATION}/${file}"
done 9< <(find "${SOURCE}" -type f -print0)

EDIT: Removed usage of -printf of find tool, as it seemingly didn't exists in mac os x - used bash parameter substitution to recreate the behavior.

Answer 3

You can try using touch in for loop:

cd /PATH/TO/SOURCE/FOLDER/
for f in *; 
 do touch /PATH/TO/DEST/FOLDER/$f; 
done

EDIT: The code above will give you all files and folders in /SOURCE/FOLDER , but will not be recursive . To create empty files only for source files and to create a directory tree(all the subfolders), you can use:

FILES=$(find /PATH/TO/SOURCE/FOLDER/ -type f) 
for f in $FILES; 
do touch /PATH/TO/DEST/FOLDER/$f;
done

I hope it helps!