# HG changeset patch
# User Jim Hague <jim.hague@acm.org>
# Date 1477779525 -3600
# Node ID 696c461c8dc01f4d6a2484c6cde22e0aa4381ebc
# Parent  0206ab9fd6baa39ad751fb918aea344cc783a2c1
Set exit status on abcfield.py to indicate if anything found.

diff -r 0206ab9fd6ba -r 696c461c8dc0 abcfield.py
--- a/abcfield.py	Sat Oct 29 21:51:59 2016 +0100
+++ b/abcfield.py	Sat Oct 29 23:18:45 2016 +0100
@@ -130,6 +130,7 @@
                 continue
             found = True
             print(convertField(line, options))
+    return found
 
 parser = optparse.OptionParser(usage="usage: %prog [options] [filename]\n\n"
                                      "  Extract field data from ABC file.")
@@ -148,13 +149,14 @@
                   metavar="CONTENT")
 (options, args) = parser.parse_args()
 
+res = False
 if len(args) > 0:
     for arg in args:
         try:
             inf = open(arg, "r")
-            process(inf, options)
+            res = res or process(inf, options)
         finally:
             inf.close()
 else:
-    process(sys.stdin, options)
-sys.exit(0)
+    res = process(sys.stdin, options)
+sys.exit(int(not res))