add run linux commands

bin/main.cpp

@@ -178,4 +178,8 @@ int main(int argc, char *argv[])
     auto combine ( hack::utils::func_concat(plus, minus) );
     hack::log("")("func_concat result: ", combine(3));
   }
+
+  {// ex: utils::exec
+    hack::log()(hack::utils::exec("ls"));
+  }
 }

src/utils/utils.hpp

@@ -2,6 +2,8 @@
 
 #include <map>
 #include <functional>
+#include <memory>
+#include <string>
 
 namespace hack::utils
 {
@@ -43,4 +45,23 @@ namespace hack::utils
       };
     }
   }
+
+  inline std::string exec(const char* cmd) 
+  {
+    std::array<char, 128> buffer;
+    std::string result;
+    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd, "r"), pclose);
+
+    if (!pipe) 
+    {
+      throw std::runtime_error("popen() failed!");
+    }
+    
+    while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) 
+    {
+      result += buffer.data();
+    }
+
+    return result;
+  }
 }