--- a/abcfield.py	Thu Oct 12 11:21:48 2017 +0100
+++ b/abcfield.py	Thu Oct 12 11:59:28 2017 +0100
@@ -17,7 +17,7 @@
 # break between it and the previous line.
 #
 
-import optparse
+import argparse
 import pathlib
 import re
 import subprocess
@@ -239,17 +239,17 @@
     return title if len(subtitle) == 0 else title + " (" + subtitle + ")"
 
 if __name__ == "__main__":
-    def process(f, dir, options):
+    def process(f, dir, args):
         lines = f.readlines()
-        if options.display:
-            if options.field.upper() == "FT":
-                line = getFullTitle(lines, dir, options.starts, options.latex)
+        if args.display:
+            if args.field.upper() == "FT":
+                line = getFullTitle(lines, dir, args.starts, args.latex)
             else:
-                line = getFieldDisplayText(lines, dir, options.field, options.index, options.starts, options.latex)
+                line = getFieldDisplayText(lines, dir, args.field, args.index, args.starts, args.latex)
         else:
-            if options.field.upper() == "FT":
-                options.field = "T"
-            line = getFieldText(lines, options.field, options.index, options.starts)
+            if args.field.upper() == "FT":
+                args.field = "T"
+            line = getFieldText(lines, args.field, args.index, args.starts)
         if line:
             print(line)
             return True
@@ -257,32 +257,39 @@
             return False
 
     # execute only if run as a script
-    parser = optparse.OptionParser(usage="usage: %prog [options] [filename]\n\n"
-                                   "  Extract field data from ABC file.")
-    parser.add_option("-f", "--field", dest="field", default="T",
-                      help="extract the field FIELD", metavar="FIELD")
-    parser.add_option("-l", "--latex", dest="latex",
-                      action="store_true", default=False,
-                      help="convert special characters for LaTeX")
-    parser.add_option("-d", "--display", dest="display",
-                      action="store_true", default=False,
-                      help="convert to display text")
-    parser.add_option("-n", "--index", dest="index",
-                      action="store", type="int", default=1,
-                      help="report INDEXth value [default: %default]",
-                      metavar="INDEX")
-    parser.add_option("-s", "--starts", dest="starts",
-                      action="store", type="string", default=None,
-                      help="report only if line starts CONTENT and remove CONTENT",
-                      metavar="CONTENT")
-    (options, args) = parser.parse_args()
+    parser = argparse.ArgumentParser(description="Extract field data from ABC file.")
+    parser.add_argument("-f", "--field", dest="field", default="T",
+                        help=("extract the given field [default: %(default)s]. "
+                              "Field FT is special; it returns the full title "
+                              "- the title followed by subtitle in () if "
+                              "present - for display text, or just the title "
+                              "for non-display text."))
+    parser.add_argument("-l", "--latex", dest="latex",
+                        action="store_true", default=False,
+                        help="convert special characters for LaTeX (default HTML)")
+    parser.add_argument("-d", "--display", dest="display",
+                        action="store_true", default=False,
+                        help=("convert to display text. Convert accents to "
+                              "LaTeX or HTML, in titles convert 'Tune, The' to "
+                              "'The Tune', convert keys to full key name, "
+                              "and expand Markdown in notes and history."))
+    parser.add_argument("-n", "--index", dest="index",
+                        action="store", type=int, default=1,
+                        help="report INDEXth value [default: %(default)s]")
+    parser.add_argument("-s", "--starts", dest="starts",
+                        action="store", default=None,
+                        help=("report only if line starts with CONTENT "
+                              "and remove CONTENT"),
+                        metavar="CONTENT")
+    parser.add_argument('input', type=argparse.FileType('r'),
+                        help='input ABC file')
+    args = parser.parse_args()
 
     res = False
-    if len(args) > 0:
-        for arg in args:
-            path = pathlib.Path(arg)
-            with path.open() as f:
-                res = res or process(f, path.parent, options)
+    if args.input:
+        path = pathlib.Path(args.input.name)
+        with path.open() as f:
+            res = process(f, path.parent, args)
     else:
-        res = process(sys.stdin, ".", options)
+        res = process(sys.stdin, ".", args)
     sys.exit(int(not res))