How can I add OS X “tags” to files programmatically?

Question

Since Mavericks, OS X has had the ability to tag & colour files in Finder.

Is there any

Answer 1

The OpenMeta framework is a third-party standard for adding metadata to OS X files using extended attributes. It is used by a number of third-party applications.

Or you can use the XATTR command to manipulate the extended attributes via command line.

Answer 2

You could give this a shot:

xattr -w com.apple.metadata:_kMDItemUserTags '<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"><plist version="1.0"><array><string>Orange</string><string>Red</string></array></plist>' $currentFile

You'll want to replace $currentFile with the file you'd like to add tags to, and change

<string>Orange</string><string>Red</string>

to a list of whatever tags you want to add.

Answer 3

In Ask Different

With multiple answers, one of which is accepted:

• Possible to tag a folder via terminal? (2013-11-15)

---

Here in Stack Overflow the question arose slightly earlier (2013-11-01) so I'll add my answer here.

openmeta

Open source at https://code.google.com/p/openmeta/source/browse/trunk/trunk/openmeta

The openmeta command appears to take a dual attribute approach, working with both:

• com.apple.metadata:kMDItemOMUserTags
• com.apple.metadata:_kMDItemUserTags

Example usage

sh-3.2$ sw_vers
ProductName:    Mac OS X
ProductVersion: 10.9.5
BuildVersion:   13F1096
sh-3.2$ uname -a
Darwin gpes3e-gjp4.local 13.4.0 Darwin Kernel Version 13.4.0: Wed Mar 18 16:20:14 PDT 2015; root:xnu-2422.115.14~1/RELEASE_X86_64 x86_64
sh-3.2$ date
Sun 26 Jul 2015 08:00:23 BST
sh-3.2$ rm ~/Desktop/test.txt 
sh-3.2$ touch ~/Desktop/test.txt 
sh-3.2$ xattr -l ~/Desktop/test.txt 
sh-3.2$ ./openmeta
openmeta version 0.1 by Tom Andersen code.google.com/p/openmeta/ 

Usage: openmeta [options] -p PATH[s] 

Note that commas are to be used nowhere - tag lists use quotes for two word tags in output

example (list tags and ratings):  openmeta -p PATH
example (list tags and ratings multiple):  openmeta -p PATH PATH
example (list tags): openmeta -t -p PATH[s]
example (add tags): openmeta -a foo bar -p PATH[s]
example (add tags with spaces): openmeta -a "three word tag" "foo bar" -p PATH[s]
example (set tags):  openmeta -s foo bar -p PATH[s]
example (clear all tags):  openmeta -s -p PATH[s]
example (set managed):  openmeta -m Y -p PATH[s]
example (set rating 0 - 5 stars):  openmeta -r 3.5 -p PATH[s]
example (print rating):  openmeta -r -p PATH[s]
example (clear rating):  openmeta -r 0.0 -p PATH[s]
example (lousy rating):  openmeta -r 0.1 -p PATH[s]
sh-3.2$ ./openmeta -a kerfuffle -p ~/Desktop/test.txt 
kerfuffle /Users/gjp22/Desktop/test.txt
sh-3.2$ ./openmeta -p ~/Desktop/test.txt 
/Users/gjp22/Desktop/test.txt
tags: kerfuffle
rating: none found

sh-3.2$ xattr -l ~/Desktop/test.txt 
com.apple.metadata:kMDItemOMUserTagTime:
00000000  62 70 6C 69 73 74 30 30 33 41 BB 64 BD 3C D4 95  |bplist003A.d.<..|
00000010  F2 08 00 00 00 00 00 00 01 01 00 00 00 00 00 00  |................|
00000020  00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00  |................|
00000030  00 11                                            |..|
00000032
com.apple.metadata:kMDItemOMUserTags:
00000000  62 70 6C 69 73 74 30 30 A1 01 59 6B 65 72 66 75  |bplist00..Ykerfu|
00000010  66 66 6C 65 08 0A 00 00 00 00 00 00 01 01 00 00  |ffle............|
00000020  00 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00  |................|
00000030  00 00 00 00 00 14                                |......|
00000036
com.apple.metadata:_kMDItemUserTags:
00000000  62 70 6C 69 73 74 30 30 A1 01 5B 6B 65 72 66 75  |bplist00..[kerfu|
00000010  66 66 6C 65 0A 30 08 0A 00 00 00 00 00 00 01 01  |ffle.0..........|
00000020  00 00 00 00 00 00 00 02 00 00 00 00 00 00 00 00  |................|
00000030  00 00 00 00 00 00 00 16                          |........|
00000038
kOM109SyncDone:
00000000  62 70 6C 69 73 74 30 30 09 08 00 00 00 00 00 00  |bplist00........|
00000010  01 01 00 00 00 00 00 00 00 01 00 00 00 00 00 00  |................|
00000020  00 00 00 00 00 00 00 00 00 09                    |..........|
0000002a
sh-3.2$ 

Limitations of other utilities

Apple Finder, for example.

After using Finder to remove the kerfuffle tag, kerfuffle remains as an OpenMeta tag:

sh-3.2$ date ; xattr -l ~/Desktop/test.txt 
Sun 26 Jul 2015 08:02:13 BST
com.apple.metadata:kMDItemOMUserTagTime:
00000000  62 70 6C 69 73 74 30 30 33 41 BB 64 BD 3C D4 95  |bplist003A.d.<..|
00000010  F2 08 00 00 00 00 00 00 01 01 00 00 00 00 00 00  |................|
00000020  00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00  |................|
00000030  00 11                                            |..|
00000032
com.apple.metadata:kMDItemOMUserTags:
00000000  62 70 6C 69 73 74 30 30 A1 01 59 6B 65 72 66 75  |bplist00..Ykerfu|
00000010  66 66 6C 65 08 0A 00 00 00 00 00 00 01 01 00 00  |ffle............|
00000020  00 00 00 00 00 02 00 00 00 00 00 00 00 00 00 00  |................|
00000030  00 00 00 00 00 14                                |......|
00000036
com.apple.metadata:_kMDItemUserTags:
00000000  62 70 6C 69 73 74 30 30 A0 08 00 00 00 00 00 00  |bplist00........|
00000010  01 01 00 00 00 00 00 00 00 01 00 00 00 00 00 00  |................|
00000020  00 00 00 00 00 00 00 00 00 09                    |..........|
0000002a
kOM109SyncDone:
00000000  62 70 6C 69 73 74 30 30 09 08 00 00 00 00 00 00  |bplist00........|
00000010  01 01 00 00 00 00 00 00 00 01 00 00 00 00 00 00  |................|
00000020  00 00 00 00 00 00 00 00 00 09                    |..........|
0000002a
sh-3.2$ 

Understanding those limitations

With attention to domains and naming conventions: Developer thoughts on adopting OpenMeta – Ironic Software (2009-03, and now in the Internet Archive Wayback Machine) reminds us that com.apple.metadata was for use by Apple when OpenMeta (a project not in the apple.com domain) began the Apple-oriented com.apple.metadata:kMDItemOMUserTags approach.

So I should not expect Apple software to gain or maintain compatibility with both approaches to tagging.

---

Edge cases

In some cases it may be desirable to remove Apple-oriented com.apple.metadata:_kMDItemUserTags tags without removing OpenMeta-oriented com.apple.metadata:kMDItemOMUserTags tags.

However, doing so – programmatically – is probably beyond the scope of the question asked by @nacross.