perl pie escape the delimeter

Question

I'm running this perl cmd on Mac OS to delete the whole line.

perl -i -pe's/<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="@string/fb_app_id"/>/ /g' AndroidManifest.xml

The result is

fb_app_id"@string/fb_app_id"/> 

I'm unable to escape the / in "@string/fb_app_id tried different variations @string//fb_app_id and @string\/fb_app_id but none worked.

Answer 1

If you had been using warnings, you would have been notified that @strings is being considered a variable and interpolated in the regex. You should try to escape the @. And also the slashes.

perl -i -pe's/<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\@string\/fb_app_id"\/>\/ /g' AndroidManifest.xml 

Running a Perl command without warnings is a bad idea, even if you are a Perl expert.

Notable things:

• You should not parse XML with a regex. Related infamous answer.
• You do not need to use a substitution, you can try a looser match using m// with the -n switch, and then avoid printing matching lines. E.g.

perl -i -nwe'print unless m|android:value="\@string/fb_app_id"|'

Answer 2

Can you try using delimiter [] ?

perl -i -pe's[<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\@string/fb_app_id"/>][ ]g' AndroidManifest.xml

Answer 3

Notwithstanding the hazzards of using regex on XML, here is how you would normally do a task like this.

Use curly braces as the delimiters. s{}{}
Manually escape these characters. $ @ \ --> \$ \@ \\
If it's a fixed string, wrap it with \Q\E. Otherwise periods and other regex meta characters will cause unintended effects.

perl -i.bak -pe 's{\Q<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\@string/fb_app_id"/>\E}{ }g' AndroidManifest.xml

To merely comment out the block:

perl -i.bak -pe 's{(\Q<meta-data android:name="com.facebook.sdk.ApplicationId" android:value="\@string/fb_app_id"/>\E)}{<!-- $1 -->}g' AndroidManifest.xml

HTH