How can I add a kMDItemWhereFroms attribute to a file?

Usually something like...

xattr -w com.apple.metadata:kMDItemWhereFroms {url} {filename}

would attach the specified {url} onto the specified {filename}.

There's a related write-up over at Macworld.

You can place your links into an array in a regular XML property list and just write that, for example:

xattr -w 'com.apple.metadata:kMDItemWhereFroms' '<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><array><string>http://www.where.do.I.come.from</string></array></plist>' /path/to/your/file

You can also use plutil to convert the XML to a binary property list by using binary1 for the convert format. When converting to the binary property list, you can use xxd to get the hexadecimal, but you also need to use the -x option with xattr so that it writes the hex and not the string.

I don't know what your workflow looks like, but you would convert the XML property list to binary by using something like (std in/out):

plutil -convert binary1 -o - - | xxd -p

...and once in binary form you would use the -x option with xattr:

xattr -w -x com.apple.metadata:kMDItemWhereFroms bplist file

The documentation isn't too bad, at least on the options used here. I don't have a shell script, but have a working Applescript, with conversions back and forth.

I think with the argument arrangements you will probably have to use a variable (or file) for the intermediate values (that is what I did, anyway). The following script doesn't check if the current setting is not a property list (which wouldn't show up in the Finder or Spotlight anyway), but has shell script pieces to get, set, and convert from/to binary:

-- view and manipulate 'com.apple.metadata:kMDItemWhereFroms' extended attribute # switches to alter script operation: property remove : false -- remove the attribute? property binary : true -- set binary plist? set action to "Set" if remove then set action to "Remove" set theFile to quoted form of POSIX path of (choose file with prompt action & " 'com.apple.metadata:kMDItemWhereFroms' attribute:") set attribute to missing value try -- get existing attribute as property list   set attribute to (do shell script "xattr -p com.apple.metadata:kMDItemWhereFroms " & theFile & "  | xxd -r -p | plutil -convert xml1 -o - -") -- convert from binary on error -- oops, not a binary plist, so try XML   try -- skip error if no attribute     set attribute to (do shell script "xattr -p com.apple.metadata:kMDItemWhereFroms " & theFile)   end try end try log attribute if remove then -- delete attribute   try -- skip error if no attribute     do shell script "xattr -d com.apple.metadata:kMDItemWhereFroms " & theFile   end try else -- add   if attribute is missing value then -- create example property list     set plist to "<?xml version=\"1.0\" encoding=\"UTF-8\"?> <!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\"> <plist version=\"1.0\"> <array>     <string>http://www.where.do.I.come.from</string>     <string>http://www.some.other.place</string> </array> </plist>"   else -- reuse existing     set plist to attribute   end if   if binary then -- convert and set binary plist     set bplist to do shell script "echo " & quoted form of plist & " | plutil -convert binary1 -o - - | xxd -p"     do shell script "xattr -w -x com.apple.metadata:kMDItemWhereFroms " & bplist & space & theFile   else -- set XML plist     do shell script "xattr -w com.apple.metadata:kMDItemWhereFroms " & quoted form of plist & space & theFile   end if end if

I mainly use file paths, but it looks like the issue is just with &<>" (and maybe the backslash), which need to be escaped in a property list. For example, www.somewhere.com/&amp;+,/:;=?@&lt;&gt;[]{}|\\^~%#'&quot; works with the above script.

Edit: trying to get the string past the formatting

I like this , but you have a small typo in that you need comma-separated quoted strings, not quoted, comma-separated strings in the input to plutil.

myUrl=`echo \(\'http://www.google.com\',\'https://www.google.com\'\) | plutil -convert binary1 -o - - | xxd -p -c 16 -u` ; xattr -xw com.apple.metadata:kMDItemWhereFroms "$myUrl" test.txt

Or formatted for inclusion in a shell script:

url1="http://www.example.com/test.txt" ; \

url2="http://www.example.com/?search=test.txt" ; \

xattr -xw com.apple.metadata:kMDItemWhereFroms \

"`echo \(\'$url1\',\'$url2\'\) | \

plutil -convert binary1 -o - - | \

xxd -p -c 16 -u`" \

test.txt