re-write CLI argument parsing for testability

tools/put.cpp

@@ -9,7 +9,6 @@
 #include <atomic>
 
 #include <epicsVersion.h>
-#include <epicsGetopt.h>
 #include <epicsThread.h>
 
 #define PVXS_ENABLE_EXPERT_API
@@ -19,6 +18,11 @@
 #include <pvxs/json.h>
 #include "utilpvt.h"
 #include "evhelper.h"
+#include "cliutil.h"
+
+#ifndef REALMAIN
+#  define REALMAIN main
+#endif
 
 using namespace pvxs;
 
@@ -37,9 +41,9 @@ void usage(const char* argv0)
                ;
 }
 
-}
+} // namespace
 
-int main(int argc, char *argv[])
+int REALMAIN(int argc, char *argv[])
 {
     try {
         logger_config_env(); // from $PVXS_LOG
@@ -47,55 +51,53 @@ int main(int argc, char *argv[])
         bool verbose = false;
         std::string request;
 
-        {
-            int opt;
-            while ((opt = getopt(argc, argv, "hvVdw:r:")) != -1) {
-                switch(opt) {
-                case 'h':
-                    usage(argv[0]);
-                    return 0;
-                case 'V':
-                    std::cout<<pvxs::version_information;
-                    return 0;
-                case 'v':
-                    verbose = true;
-                    break;
-                case 'd':
-                    logger_level_set("pvxs.*", Level::Debug);
-                    break;
-                case 'w':
-                    timeout = parseTo<double>(optarg);
-                    break;
-                case 'r':
-                    request = optarg;
-                    break;
-                default:
-                    usage(argv[0]);
-                    std::cerr<<"\nUnknown argument: "<<char(opt)<<std::endl;
-                    return 1;
-                }
+        GetOpt opts(argc, argv, "hvVdw:r:");
+        for(auto& pair : opts.arguments) {
+            switch(pair.first) {
+            case 'h':
+                usage(opts.argv0);
+                return 0;
+            case 'V':
+                std::cout<<pvxs::version_information;
+                return 0;
+            case 'v':
+                verbose = true;
+                break;
+            case 'd':
+                logger_level_set("pvxs.*", Level::Debug);
+                break;
+            case 'w':
+                timeout = pair.second.as<double>();
+                break;
+            case 'r':
+                request = *pair.second;
+                break;
+            default:
+                usage(opts.argv0);
+                std::cerr<<"\nUnknown argument: "<<pair.first<<std::endl;
+                return 1;
             }
         }
 
-        if(optind==argc) {
-            usage(argv[0]);
-            std::cerr<<"\nExpected PV name\n";
+        if(opts.positional.size()<2) {
+            usage(opts.argv0);
+            std::cerr<<"\nExpected PV name and at least one value\n";
             return 1;
         }
 
-        std::string pvname(argv[optind++]);
+        const auto& pvname = opts.positional.front();
         std::map<std::string, std::string> values;
 
-        if(argc-optind==1 && std::string(argv[optind]).find_first_of('=')==std::string::npos) {
+        if(opts.positional.size()==2 && std::string(opts.positional[1]).find_first_of('=')==std::string::npos) {
             // only one field assignment, and field name omitted.
             // if JSON map, treat as entire struct.  Others imply .value
 
-            auto sval(argv[optind]);
+            const auto& sval = opts.positional[1];
             values[sval[0]=='{' ? "" : "value"] = sval;
 
         } else {
-            for(auto n : range(optind, argc)) {
-                std::string fv(argv[n]);
+            for(auto n : range(size_t(1), opts.positional.size())) {
+                std::string fv(opts.positional[n]);
                 auto sep = fv.find_first_of('=');
 
                 if(sep==std::string::npos) {