Add extract command to extract the DOI

1 files changed, 17 insertions, 1 deletions

diff --git a/bibtool/cli.py b/bibtool/cli.py
index 6fe0890..63e3d5b 100644
--- a/bibtool/cli.py
+++ b/bibtool/cli.py
@@ -19,13 +19,29 @@ def cli():
     pass
 
 
+@cli.command('extract')
+@click.argument('filename', type=TYPE_FILE)
+@click.option('--all/--single', '-a/-s', 'print_all', default=False)
+def _extract(filename, print_all):
+    for doi in bibtool.extract.get_doi_generator(filename):
+        print(doi)
+        if not print_all:
+            return
+
+
 @cli.command('import')
 @click.argument('filename', type=TYPE_FILE)
 @click.option('--directory', type=TYPE_DIR, default=os.getcwd())
 @click.option('--delete/--no-delete', default=False)
 @click.option('--doi', type=str, default=None)
 def _import(filename, directory, delete, doi):
-    bibtex_data = bibtool.extract.get_bibtex_data(filename, doi)
+    doi_generator = bibtool.extract.get_doi_generator(filename)
+    try:
+        doi = next(doi_generator)
+    except StopIteration:
+        raise Exception('Could not extract a DOI from {}'.format(filename))
+
+    bibtex_data = bibtool.extract.get_bibtex_data(doi)
 
     if not bibtex_data.entries:
         raise Exception('Did not find any Bibtex entry.')