--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/abcrange.py	Thu Jul 18 15:27:57 2013 +0100
@@ -0,0 +1,95 @@
+#!/usr/bin/env python
+#
+# Find the range of a tune. Do minimal parsing of an ABC input file
+# and print the lowest and highest notes therein. Accidentals are
+# ignored.
+#
+# The output is given in purely numeric form, to avoid needing to
+# re-parse it in an external script. A single line is printed with
+# the highest note followed by a space and the lowest note. Middle C ('C') is
+# 100. D an octave about ('d') is 108. D an octave above that ('d'') is
+# 205. D below middle C ('d,') is 94. And so on.
+#
+# For example:
+# $./abcrange.py choon.abc
+# choon.abc: 112 97
+#
+
+import sys
+
+def process(filename, inf):
+    highest = 0
+    lowest = 1000
+    for line in inf:
+        line = line.strip()
+        # If it is empty or starts "%", ignore it.
+        if len(line) == 0 or line[0] == "%":
+            continue
+
+        # Is it a header line? I.e. does it start LETTER COLON?
+        # If so, ignore.
+        start = line[:2]
+        if len(start) > 1 and start[1] == ":" and start[0].isalpha():
+            continue
+
+        # Tune line.
+        inchord = False
+        note = 0
+        notevals = {
+            "C": 100,
+            "D": 101,
+            "E": 102,
+            "F": 103,
+            "G": 104,
+            "A": 105,
+            "B": 106,
+            "c": 107,
+            "d": 108,
+            "e": 109,
+            "f": 110,
+            "g": 111,
+            "a": 112,
+            "b": 113,
+        }
+        for c in line:
+            if c == "," and note > 0:
+                note = note - 7
+                continue
+            elif c == "'" and note > 0:
+                note = note + 7
+                continue
+
+            if note > 0:
+                if note > highest:
+                    highest = note
+                if note < lowest:
+                    lowest = note
+                note = 0
+
+            if c == '"':
+                inchord = not inchord
+                continue
+            if inchord:
+                continue
+
+            if c in notevals:
+                note = notevals[c]
+
+        if note > 0:
+            if note > highest:
+                highest = note
+            if note < lowest:
+                lowest = note
+            note = 0
+
+    print "{0}: {1} {2}".format(filename, highest, lowest)
+
+if len(sys.argv) > 1:
+    for arg in sys.argv[1:]:
+        try:
+            inf = open(arg, "r")
+            process(arg, inf)
+        finally:
+            inf.close()
+else:
+    process("stdin", sys.stdin)