color: take care of handling --[no-]color options

Author: kdudka

color.hh

@@ -46,4 +46,32 @@ class ColorWriter {
         bool enabled_;
 };
 
+template <class TOptDesc>
+void addColorOptions(TOptDesc *desc) {
+    desc->add_options()
+        ("color",
+         "use colorized console output (default if connected to a terminal)")
+        ("no-color",
+         "do not use colorized console output");
+}
+
+template <class TValMap>
+bool readColorOptions(EColorMode *pDst, const char **pErr, const TValMap &vm) {
+    const bool colorAlways = vm.count("color");
+    const bool colorNever = vm.count("no-color");
+    if (colorAlways && colorNever) {
+        *pErr = "options --color and --no-color are mutually exclusive";
+        return false;
+    }
+
+    if (colorAlways)
+        *pDst = CM_ALWAYS;
+    else if (colorNever)
+        *pDst = CM_NEVER;
+    else
+        *pDst = CM_AUTO;
+
+    return true;
+}
+
 #endif /* H_GUARD_COLOR_H */

csgrep.cc

@@ -503,10 +503,10 @@ int main(int argc, char *argv[])
 
             ("ignore-case,i",                                   "ignore case when matching regular expressions")
             ("invert-match,v",                                  "select defects that do not match the selected criteria")
-            ("invert-regex,n",                                  "invert regular expressions in all predicates")
+            ("invert-regex,n",                                  "invert regular expressions in all predicates");
 
-            ("color",                                           "use colorized console output (default if connected to a terminal)")
-            ("no-color",                                        "do not use colorized console output")
+        addColorOptions(&desc);
+        desc.add_options()
             ("quiet,q",                                         "do not report any parsing errors")
 
             ("mode",                po::value<string>(&mode)
@@ -547,17 +547,14 @@ int main(int argc, char *argv[])
     }
 
     // handle --[no-]color options
-    const bool color_always = vm.count("color");
-    const bool color_never = vm.count("no-color");
-    if (color_always && color_never) {
-        std::cerr << name << ": error: "
-            "options --color and --no-color are mutually exclusive\n";
+    EColorMode cm;
+    const char *err;
+    if (readColorOptions(&cm, &err, vm))
+        WriterFactory::setColorMode(cm);
+    else {
+        std::cerr << name << ": error: " << err << std::endl;
         return 1;
     }
-    if (color_always)
-        WriterFactory::setColorMode(CM_ALWAYS);
-    if (color_never)
-        WriterFactory::setColorMode(CM_NEVER);
 
     // create a writer according to the selected mode
     WriterFactory factory;