Checkpoint Location Format

Hi,

I'm writing an automated file-system level backup application for use
with WAL archiving, that will issue the pg_start_backup call, tar and
gzip the cluster data directory, issue the pg_stop_backup call, and
remove all previous un-needed WAL files from the archive.

I need to write a regular expression that will search for the WAL
filename and checkpoint location from the backup_label file, and just
want to clarify that the checkpoint location will always be of the
format: X/XXXXXX - where X is one of 0-9, A-F?

And then the WAL .backup file that is generated in the archive, has a
filename of the form:

<WAL_FILE>.00XXXXXX.backup

where <WAL_FILE> is the name of the "STARTING WAL LOCATION" directive in
the backup_label file, and XXXXXX is the last 6 digits of the checkpoint
(after the / )?

Thanks,

Andy.