cam: options: optional arguments needs to be specified as --foo=bar

It's not stated in the getopt_long documentation but optional arguments
need to be specified as '--foo=bar' instead of '--foo bar', otherwise
the value is not propagated to optarg during argument parsing. Update
the usage printing helper to reflect this requirement.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/cam/options.cpp b/src/cam/options.cpp
index 82acff9b..55c42540 100644
--- a/src/cam/options.cpp
+++ b/src/cam/options.cpp
@@ -143,9 +143,10 @@ void OptionsParser::usage()
 		};
 
 		if (option.argument != ArgumentNone) {
-			argument += std::string(" ");
 			if (option.argument == ArgumentOptional)
-				argument += "[";
+				argument += "[=";
+			else
+				argument += " ";
 			argument += option.argumentName;
 			if (option.argument == ArgumentOptional)
 				argument += "]";