funkpower
19e5f3ddc3
`bibfetch::cover(&agent, isbn, cover_id, size)` asks Open Library's covers store by the ISBN's thirteen-digit form, then its ten-digit form, then by a cover id a lookup record named, and returns the image or `Ok(None)`. The answer is checked before it is trusted: JPEG or PNG by content type and by magic bytes, between 1 KB and 10 MB, at most three redirects, none of them off HTTPS. One request at a time per process; a 429 or 503 is waited out for its Retry-After, up to a minute. `idnorm::isbn` converts between the two forms, and only for an ISBN whose check digit agrees. Lookup records carry `cover_id` from the edition record and the search index. The CLI gains `bibfetch cover <isbn> -o <file>`.
6.5 KiB
bibfetch
What a catalogue says about an identifier, asked of the body that assigns it.
Part of catena.
What it does
idnorm can tell you a DOI is well formed. It cannot
tell you the paper exists — that is not a fact about the string, it is a fact
about the world, and the only way to learn it is to ask somebody who keeps a
register.
So this asks, and that is the only thing it does.
When you would use it
- Auditing a bibliography. A well-formed DOI that no register has is a mistyped one, and a catalogue can carry it for years without noticing.
- Filling in a reference you have only the identifier for.
- Before citing something, to check the year and the authors are what you think they are.
Install
cargo install --git https://git.pumpin.online/funkpower/catena bibfetch
Example
$ printf '10.1093/mind/LIX.236.433\narXiv:2401.01234\n978-0-306-40615-7\n' | idnorm | bibfetch --polite [email protected]
{"v":1,"id":"10.1093/mind/lix.236.433","kind":"doi","found":true,"source":"crossref","title":"I.—COMPUTING MACHINERY AND INTELLIGENCE","authors":["A. M. TURING"],"year":1950,"container":"Mind"}
{"v":1,"id":"2401.01234","kind":"arxiv","found":true,"source":"arxiv","title":"Mixture cure semiparametric additive hazard models under partly interval censoring -- a penalized likelihood approach","authors":["Jinqing Li","Jun Ma"],"year":2024,"container":"arXiv","summary":"Survival analysis can sometimes involve individuals who will not experience…"}
{"v":1,"id":"9780306406157","kind":"isbn","found":true,"source":"openlibrary","title":"Error-correction coding for digital communications","year":1981,"container":"Plenum Press"}
The ones nobody has:
$ printf '10.9999/definitely-not-a-real-doi\n' | idnorm | bibfetch
{"v":1,"id":"10.9999/definitely-not-a-real-doi","kind":"doi","found":false,"source":"crossref"}
$ echo $?
1
Absence is the useful answer here. It is what tells a catalogue that a DOI it has been carrying for three years was mistyped on the way in.
Auditing a whole bibliography:
idnorm --quiet refs.txt | bibfetch --polite [email protected] \
| jq -r 'select(.found | not) | "missing: \(.id)"'
Options
| Option | Effect |
|---|---|
--polite <EMAIL> |
An address to put in the request. The registers ask for one and answer faster when they get it |
--timeout <SECONDS> |
How long to wait on a register. Default 20 |
--attempts <COUNT> |
How many times to ask before believing a failure. Default 3 |
--man |
Write this page as a manual page, in roff |
Exit codes
| Code | Meaning |
|---|---|
0 |
Every identifier was found |
1 |
At least one was not |
64 |
The command line was wrong |
65 |
The input was not identifier records |
69 |
A register could not be reached |
74 |
The file could not be read |
Exit 1 is an answer — the register replied and does not have it. Exit 69
is a failure — nobody replied, and the identifier may be perfectly good.
The registers
| Kind | Asked of | Why that one |
|---|---|---|
doi |
Crossref | It assigns most scholarly DOIs |
arxiv |
the arXiv | Its own register of preprints |
isbn |
OpenLibrary's edition record, then its index, then Google Books | Books, without a key |
One register is enough for a DOI or a preprint: the body that assigns the identifier is the only one that has it. A book is different. An ISBN is assigned by a publisher and recorded by whoever gets round to it, so an answer that names the book but not who wrote it is common — OpenLibrary's edition record names its authors by key rather than by name, and its index names them. So the registers are asked in turn and the first complete answer wins. An incomplete one is kept in case nothing better comes, and a register being down is a failure only when every register is.
Google Books is asked last because it answers anonymous callers only until a
daily quota runs out, after which it replies 429 to everyone sharing the
address.
An ISSN has no register that answers without a key, so it is not looked up on its own. A journal's ISSN comes back on the works published in it instead.
A failure is retried, waiting a second and then two: long enough for a register that is rate-limiting, short enough that one which is simply down does not hold up a pipeline. An answer this cannot read is not retried, because it will not read any better next time.
Covers
bibfetch cover 978-0-306-40615-7 -o cover.jpg
Fetches a book's cover from Open Library's covers store by its ISBN and
writes the image. The thirteen-digit form is asked first and the ten-digit
form second, because a book is often filed under only one of them; an ISBN
whose check digit is wrong is asked about as written, since converting it
would give another book's number. --cover-id names an Open Library cover id
to ask by last, which is what the cover_id field of a lookup record holds.
What comes back is checked before it is written: a JPEG or PNG by its bytes
as well as by what the server says, between one kilobyte (Open Library's
stand-in for a missing cover is smaller) and ten megabytes, reached in at most
three redirects that never leave HTTPS. One request is made at a time, and a
429 or 503 is waited out for as long as its Retry-After says, up to a
minute.
| Option | Effect |
|---|---|
-o, --output <FILE> |
Where to write the image |
--size <SIZE> |
small, medium or large. Default large |
--cover-id <ID> |
An Open Library cover id to ask by when the ISBN has none |
Exit 0 the cover was written, 1 Open Library has none, 65 the argument
was not an ISBN or the answer was not an image, 69 Open Library could not be
reached, 74 the file could not be written.
From Rust, bibfetch::cover(&agent, isbn, cover_id, size) returns
Ok(None) when there is no cover, and a Cover with the
bytes, the media type and the address asked when there is.
Reaching the network
This and emb are the only two tools here that do. Both
say so in --help, and for both it is the whole of what they do rather than
something that happens on the way to something else — which is the condition
under which the contract allows it at all.
Nothing is cached, nothing is stored but a cover you asked to have written,
and nothing is sent but the identifier and the address you pass to
--polite.