MacOS – How to make Rsync copy alias files

aliasapplescriptbackupmacos

System specs: 2011 iMac, OS X Mountain Lion 10.8.4

I have come to understand that Rsync does not handle Mac Alises properly, and have now discovered that hundreds of aliases I've previously copied to my portable drive, are dead and useless because of this.

Is there a way to force Rsync to handle aliases? If the answer is a definitive "no", then how can I recursively batch convert all aliases in a directory to symlinks so that they will be handled by Rsync? I've found references to an Applescript that would apparently do this, but the site hosting the script is long dead & gone.

As a last resort, does anyone know of something other than Rsync that would allow for incremental backups and also handle Aliases?

Best Answer

Rsync can't look into the content of Alias files which would be needed to convert them. So if you want to have your backup be useable as is (without restoring it to the orignal drive) you will have to replace the Aliases with symlinks.

There is a solution for this on MacOSXHints.com. It needs to be run on your original disk (not on the backup), I would also recommend to test it on some sample directories first.

#!/bin/sh
if [ $# -eq 0 ]; then
    echo "Usage: alias2ln alias1 alias2 alias3..."
    echo "  where alias1, alias2, etc are alias files."
    echo "  Each alias file will be converted into a symlink."
fi

while [ $# -gt 0 ]; do
    if [ -f "$1" -a ! -L "$1" ]; then
        item_name=`basename "$1"`
        item_parent=`dirname "$1"`
        item_parent="`cd \"${item_parent}\" 2>/dev/null && pwd || echo \"${item_parent}\"`"
        item_path="${item_parent}/${item_name}"

        linksource=`osascript<<EOS
tell app "Finder"
set theItem to (POSIX file "${item_path}") as alias
if the kind of theItem is "alias" then
get the posix path of (original item of theItem as text)
end if
end tell
EOS`

        if [ $? -eq 0 ]; then
            if [ ! -z "$linksource" ]; then
                rm "$item_path"
                ln -s "${linksource}" "${item_path}"
                echo "\"${1}\" -> \"${linksource}\""
            fi
        fi
    fi
    shift
done

To run

save the code above into a text file (e.g. alias2symlink)
execute chmod 755 alias2symlink
change to the folder where you want to convert the aliases in
execute /path/to/alias2symlink alias1 alias2 ...

Related Solutions

How to make an alias (Cmd-L) using command line

mkalias is a binary available in a set of tools here. It can also be installed via Homebrew with brew install osxutils.

This is a SH shell script that calls AppleScript to create an alias.

I'm including the shell script here for future reference incase it goes missing from the nets.

#!/bin/sh

# make_alias
# This script takes two command-line arguments:
# 1) The name (relative or full path) of a source file or folder (directory)
# 2) The name (relative or full path) of a destination folder (directory)
# The script makes a Finder-style alias to the source file or folder
# and puts it in the specified destination folder.
#
# Cameron Hayne (macdev@hayne.net), December 2003
# Modified as suggested by Paul Russell (prussell@sonic.net), May 2006
#          to allow either file or folder as source
# Mofified to work with ".app" files, January 2007

scriptname=`basename $0`
if [ $# -lt 2 ]; then
    echo "Usage: $scriptname srcPath destPath"
    exit
fi

srcPath=$1
destPath=$2

if [ ! -e "$srcPath" ]; then
    echo "$scriptname: $srcPath: No such file or directory"
    exit
fi

# remove possible trailing slash from $srcPath
srcPath=${srcPath%/}

# set $srcType to "file" or "folder" as appropriate
if [ -d "$srcPath" ]; then
    if [ "${srcPath##*.}" == "app" ]; then
        srcType="file"
    else
        srcType="folder"
    fi
else
    srcType="file"
fi

# check if the $destPath directory exists
if [ ! -d "$destPath" ]; then
    echo "$scriptname: $destPath: No such directory"
    exit
fi

# check if we have permission to create a new file in the $destPath directory
if [ ! -w "$destPath" ]; then
    echo "$scriptname: No write permission in the directory $destPath"
    exit
fi

case $srcPath in
/*) fullSrcPath=$srcPath ;;
~*) fullSrcPath=$srcPath ;;
*)  fullSrcPath=`pwd`/$srcPath ;;
esac

case $destPath in
/*) fullDestPath=$destPath ;;
~*) fullDestPath=$destPath ;;
*)  fullDestPath=`pwd`/$destPath ;;
esac

/usr/bin/osascript > /dev/null <<EOT
tell application "Finder"
    set macSrcPath to POSIX file "$fullSrcPath" as text
    set macDestPath to POSIX file "$fullDestPath" as text
    make new alias file to $srcType macSrcPath at folder macDestPath
end tell
EOT

AppleScript to show package contents of hidden original of alias

folder "Contents" of also works with aliases:

on run {input, parameters}
    tell application "Finder"
        repeat with f in input
            open folder "Contents" of f
        end repeat
    end tell
end run

You can also assign a shortcut for showing package contents from System Preferences:

Command-R shows the original file of an alias.

Best Answer

Related Solutions

How to make an alias (Cmd-L) using command line

AppleScript to show package contents of hidden original of alias

Related Question