Xapers takes as input document files (as PDF) and source identifiers. Documents are copied into a local document store (~/.xapers/docs by default) and text is extracted from the PDF and fully indexed into a Xapian database. Source identifiers are used to download document bibliographic data from online digital libraries (see SOURCES below), which are then parsed and indexed to prefixed terms in the database. The bibliographic data is also stored as bibtex in the document store for easy retrieval. Documents can be arbitrarily tagged.
A curses UI is provided for simple access to documents (see the view command below). Xapers is ultimately a document indexing library, though, so development of alternate user interfaces is encouraged.
Underlying Xapers is the wonderful Xapian database/search engine. See http://xapian.org/ for more information.
The following are the main xapers commands. See SEARCH TERMS below for details of the supported syntax for <search-terms>.
Add a document, or update an existing document. Must specify at least one of --file or --source. If search terms are provided they must match exactly one document and the matching document is updated with the newly provided information. Available options:
Import an existing bibtex database. Each bibtex entry will be added as a new document. If bibtex key, or any sources found in bibtex, match an existing document, that document is instead updated (this makes the command effectively idempotent). Any "file" fields will be parsed for document files to add. Files can be specified as a single path, or in Mendeley/Jabref format. Available options:
Add/remove tags from documents. '--' can be used to separate tagging operations from search terms.
Search for documents in the database. Document information is printed to stdout.
Specify document information to be output:
summary outputs a single-line summary of the documents (default).
bibtex outputs bibtex for all documents (if available).
tags outputs all tags associated with documents.
sources outputs all sources associated with documents.
keys outputs all bibtex citation keys associated with documents.
files outputs the full paths to all files associated with documents.
Default is summary.
Limit number of results returned to N.
Short for "search --output=bibtex <search-terms>".
Return a simple count of search results.
View search results in curses search UI. Documents matching search are displayed with their bibliographic information and a short text summary. It allows for manipulating document tags and for retrieved for document files and source URLs for viewing (see xdg-open(1) for more info). Initial search terms can be provided, but further searches can be performed from within the UI. While in the UI type "?" for available commands.
NOTE: At the moment only the top 20 search results are displayed, due to synchronous loading restrictions. This obviously needs to be fixed.
Copy PDF files of resulting documents into <directory>, named with document titles when available.
Delete documents from the database. All document files will purged from the document store.
Restore a database from existing xapers root.
These commands provide access to some of the source module methods. See SOURCES below.
Parse a source identifier string and print the corresponding source URL.
Retrieve bibtex from source for a specified URL or source id, and write to stdout.
Retrieve file from source for a specified URL or source id, and write to stdout.
Scan a document file (PDF) for source IDs, and print and recognized source ids to stdout.
Sources are online databases from which document bibliographic data can be retrieved. In Xapers, online libraries are assigned unique prefixes. The online libraries associate unique document identifiers to individual documents. See 'xapers sources' for a list of available online sources.
Xapers recognizes document a source identifier, or sid, in two forms:
full URL http://dx.doi.org/10.1364/JOSAA.29.002092
sid of form <source>:<id> doi:10.1364/JOSAA.29.002092
URLs are parsed into sources and source ids when recognized, and this information is used to retrieve bibtex from the online library databases. The sources and sids for a given document are stored as prefixed terms in the Xapers database (see below).
Xapers supports a common syntax for search terms.
Search can consist of free-form text and quoted phrases. Terms can be combined with standard Boolean operators. All terms are combined with a logical OR by default. Parentheses can be used to group operators, but must be protect from shell interpretation. The string '*' will match all documents in the database.
Additionally, the following prefixed terms are understood (where <brackets> indicate user-supplied values):
id:<docid> Xapers document ID
author:<string> string in authors (also a:)
title:<string> string in title (also t:)
tag:<tag> specific user tag
<source>:<id> specific source id (sid)
source:<source> specific source
key:<key> specific bibtex citation key
year:<year> specific publication year (also y:)
year:<since>..<until> publication year range (also y:)
year:..<until>
year:<since>..
Publication years must be four-digit integers.
See the following for more information on search terms:
http://xapian.org/docs/queryparser.html
Jameson Rollins <jrollins@finestructure.net>