Support --proto-path as alias to -I (#749)
diff --git a/generator/nanopb_generator.py b/generator/nanopb_generator.py
index c1c6f2c..b55af56 100755
--- a/generator/nanopb_generator.py
+++ b/generator/nanopb_generator.py
@@ -2056,9 +2056,9 @@
help="Set extension to use for generated source files. [default: %default]")
optparser.add_option("-f", "--options-file", dest="options_file", metavar="FILE", default="%s.options",
help="Set name of a separate generator options file.")
-optparser.add_option("-I", "--options-path", dest="options_path", metavar="DIR",
+optparser.add_option("-I", "--options-path", "--proto-path", dest="options_path", metavar="DIR",
action="append", default = [],
- help="Search for .options files additionally in this path")
+ help="Search path for .options and .proto files. Also determines relative paths for output directory structure.")
optparser.add_option("--error-on-unmatched", dest="error_on_unmatched", action="store_true", default=False,
help ="Stop generation if there are unmatched fields in options file")
optparser.add_option("--no-error-on-unmatched", dest="error_on_unmatched", action="store_false", default=False,
