c++ - I am to create a simple Command Interpreter that allows user to input commands like in any command line, but error occurs after 2 arguments -

-

command line / output 

enter command: mkdir 1 enter command: touch one/file one/other one/more error: bad address enter command: ^z

c++ source code

int main(int argc, char *argv[]){  int rs; int count = 0; pid_t pid;  char input[100]; char* temp; char* arg[6] = { (char*)0, (char*)0, (char*)0, (char*)0, (char*)0, (char*)0 };                //command    arg1      arg2      arg3      arg4      null      while(true){     cout << "enter command: ";     cin.getline(input, 100);   for( temp = strtok(input, " "); temp; temp = strtok(null, " ") )         {         arg[count++] = temp;             }         pid = fork();     if(pid == -1){     perror("error");     exit(exit_failure);     }     if(pid == 0){          /*child process*/         /*if(count < 2){              rs = execlp(arg[0],arg[0],arg[1],null);         cout << "arg[0]: " << arg[0] << "arg[1]: " << arg[1] << endl;         }         else if(count < 3){         rs = execlp(arg[0],arg[0],arg[1],arg[2],null);         cout << "arg[0]: " << arg[0] << "arg[1]: " << arg[1]              << "arg[2]: " << arg[2] << endl;         }         else if(count < 4){         rs = execlp(arg[0],arg[0],arg[1],arg[2],arg[3],null);         cout << "arg[0]: " << arg[0] << "arg[1]: " << arg[1]              << "arg[2]: " << arg[2] << "arg[3]: " << arg[3] << endl;         }         else if(count < 5){         rs = execlp(arg[0],arg[0],arg[1],arg[2],arg[3],arg[4],null);         cout << "arg[0]: " << arg[0] << "arg[1]: " << arg[1]              << "arg[2]: " << arg[2] << "arg[3]: " << arg[3]              << "arg[4]: " << arg[4] << endl;         }*/         rs = execvp(arg[0],arg);          if(rs == -1){         perror("error");         exit(exit_failure);         }        }      else{         /*parent process*/     wait(null);              }       }//end-while      }//end program

you can see commented if-else statements trying different route, did not @ all.i assume problem using execvp not understand why. appreciate feedback.

arg[count++]

you need reset count 0 after executing each command.


Comments

Post a Comment

Popular posts from this blog

Django REST Framework perform_create: You cannot call `.save()` after accessing `serializer.data` -

-
i have following viewset: class artistprofileviewset(viewsets.modelviewset): queryset = artistprofile.objects.all() serializer_class = artistprofileserializer def perform_create(self, serializer): if serializer.is_valid(): serializer.save() with following serializers: class simpleartisttrackserializer(serializers.hyperlinkedmodelserializer): class meta: model = artisttrack fields = (...my fields...) class artistprofileserializer(serializers.hyperlinkedmodelserializer): owners = userserializer(many=true, required=false) tracks = simpleartisttrackserializer(many=true, required=false) class meta: model = artistprofile fields = (...my fields...) i getting following error: assertionerror: cannot call `.save()` after accessing `serializer.data`.if need access data before committing database inspect 'serializer.validated_data' instead. i don't see editing serializer.data object. th...
Read more

Why does Go error when trying to marshal this JSON? -

-
i'm trying rather simple example of trying decode json file structs using golang. however, when attempting error that json: cannot unmarshal object go value of type []main.track which don't understand. here's code in question, , json can found here . package main import ( "encoding/json" "fmt" "net/http" "os" ) // tracks group of track types type tracks struct { tracks []track } // track represents singular track type track struct { name string url string artist artist } // artist represents single artist type artist struct { name string mbid string url string } func main() { url := "http://ws.audioscrobbler.com/2.0/?method=geo.gettoptracks&api_key=c1572082105bd40d247836b5c1819623&format=json&country=netherlands" response, err := http.get(url) if err != nil { fmt.printf("%s\n", err) os.exit(1) } de...
Read more