View source for Pi:admin pupextract

== Abstract ==

`nextpi-admin_pupextract` validates a Pi Update Patch (`.PUP`) file's header and extracts its payload archive ready for a subsequent update step.

== Prerequisits ==

* NextPi Version: 1.91D

== Backend ==
* Binary: Proprietory

== Options ==
<code>-h</code> display usage information

<code>-vl</code> verbose logging (writes to <code>/tmp/puphelper.log</code>)

<code>-c</code> check the patch's version requirement against the running system without extracting

A single positional argument names the <code>.PUP</code> file to inspect.

== Behaviour ==

The first 512 bytes of the file are read as a PUP header. The header is rejected unless its signature reads <code>PUP</code>, its secondary signature byte is <code>254</code>, and its version field is <code>1</code>. If the header's <code>strict</code> flag is set, the header's <code>piMajor</code> and <code>piMinor</code> must match the running NextPi's major and minor version; otherwise the patch is refused.

On success, the payload that follows the header is copied to <code>/ram/update.tbz</code> in 1 MiB chunks, ready for a subsequent step in the update pipeline.

== Errors ==

* File of 512 bytes or fewer — too small to contain a header.
* Header signature mismatch — not a PUP, or unsupported version.
* Strict-mode version mismatch — the running NextPi does not satisfy the patch's version requirement.