tools should have nonzero error exit codes

tools/compute_image_mean.cpp

@@ -18,7 +18,7 @@ int main(int argc, char** argv) {
   ::google::InitGoogleLogging(argv[0]);
   if (argc != 3) {
     LOG(ERROR) << "Usage: compute_image_mean input_leveldb output_file";
-    return(0);
+    return 1;
   }
 
   leveldb::DB* db;

tools/convert_imageset.cpp

@@ -38,7 +38,7 @@ int main(int argc, char** argv) {
         " RANDOM_SHUFFLE_DATA[0 or 1]\n"
         "The ImageNet dataset for the training demo is at\n"
         "    http://www.image-net.org/download-images\n");
-    return 0;
+    return 1;
   }
   std::ifstream infile(argv[2]);
   std::vector<std::pair<string, int> > lines;

tools/device_query.cpp

@@ -10,7 +10,7 @@ using namespace caffe;  // NOLINT(build/namespaces)
 int main(int argc, char** argv) {
   if (argc > 2) {
     LOG(ERROR) << "device_query [device_id=0]";
-    return 0;
+    return 1;
   }
   if (argc == 2) {
     LOG(INFO) << "Querying device_id=" << argv[1];

tools/finetune_net.cpp

@@ -16,7 +16,7 @@ int main(int argc, char** argv) {
   ::google::InitGoogleLogging(argv[0]);
   if (argc != 3) {
     LOG(ERROR) << "Usage: finetune_net solver_proto_file pretrained_net";
-    return 0;
+    return 1;
   }
 
   SolverParameter solver_param;

tools/net_speed_benchmark.cpp

@@ -25,7 +25,7 @@ int main(int argc, char** argv) {
   if (argc < 2 || argc > 5) {
     LOG(ERROR) << "net_speed_benchmark net_proto [iterations=50]"
         " [CPU/GPU] [Device_id=0]";
-    return 0;
+    return 1;
   }
 
   if (argc >=3) {

tools/test_net.cpp

@@ -20,7 +20,7 @@ int main(int argc, char** argv) {
   if (argc < 4 || argc > 5) {
     LOG(ERROR) << "test_net net_proto pretrained_net_proto iterations "
         << "[CPU/GPU]";
-    return 0;
+    return 1;
   }
 
   cudaSetDevice(0);

tools/train_net.cpp

@@ -17,7 +17,7 @@ int main(int argc, char** argv) {
   ::google::InitGoogleLogging(argv[0]);
   if (argc < 2 || argc > 3) {
     LOG(ERROR) << "Usage: train_net solver_proto_file [resume_point_file]";
-    return 0;
+    return 1;
   }
 
   SolverParameter solver_param;