doi2bibtex.py

#!/usr/bin/env python

# Take one argument--the doi, and convert it to bibtex using an API
# call to dx.doi.org.

from sys import argv
import os

if argv[0].find('doi') != -1:
    # run as executable
    doi = argv[1]
else:
    # run from python
    doi = argv[2]

cmd = ('curl -sLH "Accept: text/bibliography; style=bibtex" ' + 
       'http://dx.doi.org/' + doi)
bib_oneliner = os.popen(cmd).read()

# convert bib_oneliner to formatted (multiline) bibtex
bib = ''
# extract type
entry_type = bib_oneliner[bib_oneliner.find('@') + 1:
                          bib_oneliner.find('{')]
bib += '@' + entry_type + '{' + doi + ',\n'; # use doi as cite key
# parse body
body = bib_oneliner[bib_oneliner.find(',')+2:-2] + ','
while body:
    # match curly braces
    left_minus_right = 0
    i = 0
    while True:
        if body[i] == '{':
            left_minus_right += 1
        if body[i] == '}':
            left_minus_right -= 1
            if left_minus_right == 0:
                # outermost level matched up, one entry finished
                # advance one char for the trailing comma
                i += 1
                break
        i += 1

    bib += '  ' + body[:i+1] + '\n'
    body = body[i+1:].strip()

bib += '}'
print(bib)