MacOS下如何反向替换XML编码？解决xmllint格式化报错问题

Got it, I totally get what you're trying to do—you need to turn those escaped XML entities in your logs back into regular characters so xmllint --format stops throwing errors and gives you human-readable XML. Since you're on MacOS and have Perl available, this is straightforward.

The Core Idea #

We need to reverse the standard XML entity encoding:

• Replace & back to &
• Replace < back to <
• Replace > back to >
• (Optional) Add replacements for other common entities like " (") and ' (') if your logs use them

The One-Liner Command #

Pipe your log content through Perl first to un-escape the entities, then feed it to xmllint:

cat your-log-file.log | perl -pe 's/&amp;/&/g; s/&lt;/</g; s/&gt;/>/g;' | xmllint --format -

Breakdown of the Command:

• cat your-log-file.log: Reads your log file (replace with your actual file path)
• perl -pe '...': Processes each line of input:
  • s/&/&/g: Globally replaces all & with & (do this first—if you replace other entities first, you might break nested encodings)
  • s/&lt;/</g: Replaces all escaped < with the actual less-than sign
  • s/>/>/g: Replaces all escaped > with the actual greater-than sign
• xmllint --format -: Takes the cleaned input from stdin (-) and outputs formatted, human-readable XML

Optional: Handle More Entities #

If your logs include quoted entities, extend the Perl script:

cat your-log-file.log | perl -pe 's/&amp;/&/g; s/&lt;/</g; s/&gt;/>/g; s/&quot;/"/g; s/&apos;/'\''/g;' | xmllint --format -

The s/'/'\''/g part uses bash's escape syntax to handle the single quote correctly.

Example #

Suppose your log has this messy line:

<user><name>John&Doe</name><age>30</age></user>

After running the command, xmllint will output nicely formatted XML:

<user>
  <name>John&Doe</name>
  <age>30</age>
</user>

Just make sure to replace your-log-file.log with the actual path to your log file, and you're good to go!

内容的提问来源于stack exchange，提问作者Niccolò