Add --index parameter to allow selection of nth occurence of field.

abcfield.py

@@ -105,9 +105,13 @@ def convertTitle(t, options):
     return res
 
 def process(inf, options):
+    n = options.index
     for line in inf:
         line = line.strip()
         if len(line) > 2 and line[0] == options.field and line[1] == ':':
+            if n > 1:
+                n = n - 1
+            else:
                 print(convertTitle(line[2:].strip(), options))
                 break
 
@@ -121,6 +125,10 @@ parser.add_option("-m", "--html", dest="html",
 parser.add_option("-l", "--latex", dest="latex",
                   action="store_true", default=False,
                   help="format ouput for LaTeX")
+parser.add_option("-n", "--index", dest="index",
+                  action="store", type="int", default=1,
+                  help="report INDEXth value [default: %default]",
+                  metavar="INDEX")
 (options, args) = parser.parse_args()
 
 if options.html and options.latex: