refextract: improve argument check

[simko]

When you run refextract on a non-existent file, it tracebacks with:

UnboundLocalError: local variable 'count_auth_group' referenced before assignment

It should check the parameters properly and report the concrete problem, e.g. file non-existent, permission denied, etc.

[chayward]

on branch: refextract-countauth-fix

paired with support for arxiv file names

[simko]

Running refextract on a non-existent file does not report an error for
me; it produces empty output:

/opt/invenio/bin/refextract 1:/tmp/nonexistentfile.pdf
<?xml version="1.0" encoding="UTF-8"?>
<collection xmlns="http://www.loc.gov/MARC21/slim">
<record>
   <controlfield tag="001">1</controlfield>
   <datafield tag="999" ind1="C" ind2="6">
      <subfield code="a">Invenio/1.0.0-rc0.40-106ba refextract/1.0.0-rc0.40-106ba-1297762113-1-0-0-0-0-0-0</subfield>
   </datafield>
</record>
</collection>

It should print an error message and exit with some error code
so that clients can know something went wrong. (e.g. workflow can
halt etc)

[chayward]

on branch: refextract-countauth-fix

[Christopher Hayward <christopher.james.hayward@…>]

In [3680959b3640bbe54a013e9c3bf50af0ff7a29bf]:

refextract: fix unassigned count_auth_group

• Initialised count_auth_group in main. (closes #487)

• Updated usage information with inspire journal title output option.

• When obtaining the recid and the file location for each extraction job, split a maximum of one time, since file names with arvix notation regularly include a colon e.g. 'arxiv:9834.pdf'.

• Display an error message, regardless of the output mode, and halt extraction when either a non-existent or an unreadable pdf/text input file is provided as input.