Enable Spotlight indexing of Markdown in ~~El Capitan~~ Monterey without disabling SIP

Markdown.mdimporter.patch

--- /System/Library/Spotlight/RichText.mdimporter/Contents/Info.plist	2022-02-26 09:05:07.000000000 +0200
+++ /Library/Spotlight/Markdown.mdimporter/Contents/Info.plist	2022-03-22 21:01:30.000000000 +0200
@@ -13,27 +13,20 @@
 			<string>MDImporter</string>
 			<key>LSItemContentTypes</key>
 			<array>
-				<string>public.rtf</string>
-				<string>public.html</string>
-				<string>public.xml</string>
-				<string>public.plain-text</string>
-				<string>com.apple.traditional-mac-plain-text</string>
-				<string>com.apple.rtfd</string>
-				<string>com.apple.webarchive</string>
-				<string>org.oasis-open.opendocument.text</string>
+				<string>net.daringfireball.markdown</string>
 			</array>
 		</dict>
 	</array>
 	<key>CFBundleExecutable</key>
-	<string>RichText</string>
+	<string>Markdown</string>
 	<key>CFBundleGetInfoString</key>
 	<string>1.0, Copyright (c) 2004-2019 Apple Inc.</string>
 	<key>CFBundleIdentifier</key>
-	<string>com.apple.MDImporter.RichText</string>
+	<string>com.apple.MDImporter.Markdown</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>
-	<string>Rich Text Sniffer</string>
+	<string>Markdown Sniffer</string>
 	<key>CFBundleShortVersionString</key>
 	<string>6.9</string>
 	<key>CFBundleSupportedPlatforms</key>

• Create a copy of the system RichText.mdimporter
• patch to set it up to only index markdown
• rename it to Markdown.mdimporter
• Copy into /Library/Spotlight
• Tell spotlight to start indexing with it

cp -r /System/Library/Spotlight/RichText.mdimporter .
patch -p2 RichText.mdimporter/Contents/Info.plist < Markdown.mdimporter.patch
mv RichText.mdimporter Markdown.mdimporter
sudo cp -R Markdown.mdimporter /Library/Spotlight
mdimport -r /Library/Spotlight/Markdown.mdimporter

You need to rename the patch file to "Markdown.mdimporter.patch". Notice the missing k.

cool :)

How to rebuild the Spotlight index on your Mac:
https://support.apple.com/en-us/HT201716

things have changed slightly with Monterey, new patch:

--- RichText.mdimporter/Contents/Info.plist	2022-03-22 18:33:28.000000000 +0000
+++ Markdown.mdimporter/Contents/Info.plist	2022-03-22 18:35:51.000000000 +0000
@@ -13,14 +13,7 @@
 			<string>MDImporter</string>
 			<key>LSItemContentTypes</key>
 			<array>
-				<string>public.rtf</string>
-				<string>public.html</string>
-				<string>public.xml</string>
-				<string>public.plain-text</string>
-				<string>com.apple.traditional-mac-plain-text</string>
-				<string>com.apple.rtfd</string>
-				<string>com.apple.webarchive</string>
-				<string>org.oasis-open.opendocument.text</string>
+				<string>net.daringfireball.markdown</string>
 			</array>
 		</dict>
 	</array>
@@ -29,11 +22,11 @@
 	<key>CFBundleGetInfoString</key>
 	<string>1.0, Copyright (c) 2004-2019 Apple Inc.</string>
 	<key>CFBundleIdentifier</key>
-	<string>com.apple.MDImporter.RichText</string>
+	<string>com.apple.MDImporter.Markdown</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>
-	<string>Rich Text Sniffer</string>
+	<string>Markdown Sniffer</string>
 	<key>CFBundleShortVersionString</key>
 	<string>6.9</string>
 	<key>CFBundleSupportedPlatforms</key>

sudo cp -r /System/Library/Spotlight/Richtext.mdimporter /Libary/Spotlight/Markdown.mdimporter

--- /System/Library/Spotlight/RichText.mdimporter/Contents/Info.plist	2022-02-26 09:05:07.000000000 +0200
+++ /Library/Spotlight/Markdown.mdimporter/Contents/Info.plist	2022-03-22 21:01:30.000000000 +0200
@@ -13,27 +13,20 @@
 			<string>MDImporter</string>
 			<key>LSItemContentTypes</key>
 			<array>
-				<string>public.rtf</string>
-				<string>public.html</string>
-				<string>public.xml</string>
-				<string>public.plain-text</string>
-				<string>com.apple.traditional-mac-plain-text</string>
-				<string>com.apple.rtfd</string>
-				<string>com.apple.webarchive</string>
-				<string>org.oasis-open.opendocument.text</string>
+				<string>net.daringfireball.markdown</string>
 			</array>
 		</dict>
 	</array>
 	<key>CFBundleExecutable</key>
-	<string>RichText</string>
+	<string>Markdown</string>
 	<key>CFBundleGetInfoString</key>
 	<string>1.0, Copyright (c) 2004-2019 Apple Inc.</string>
 	<key>CFBundleIdentifier</key>
-	<string>com.apple.MDImporter.RichText</string>
+	<string>com.apple.MDImporter.Markdown</string>
 	<key>CFBundleInfoDictionaryVersion</key>
 	<string>6.0</string>
 	<key>CFBundleName</key>
-	<string>Rich Text Sniffer</string>
+	<string>Markdown Sniffer</string>
 	<key>CFBundleShortVersionString</key>
 	<string>6.9</string>
 	<key>CFBundleSupportedPlatforms</key>

anyone finding this isn't needed now with Ventura and Sonoma?