c++ - Processing command line arguments, allowing for any order -

ok creating program allows user input in order. term -1 or -2 used indicate operating mode. while argument -c precedes filename. here loop have written allow these entered in order user wishes.

int main(int argc, char *argv[]) {     string qcolors_name;     string inputfilename;     pmode_t mode = run_process2;     // perform command line argument checking     if(argc < 2){         cerr << "not enough arguments" << endl;         return 0;     }      for(int = 1; < argc - 1; i++){         if(argv[i] == "-1"){             mode = run_process1;             cout << "mode 1" << endl;         }else if(argv[i] == "-2"){             mode = run_process2;         }else if(argv[i] == "-c"){             qcolors_name = argv[i+1];             cout << qcolors_name << endl;             i++;         }else if(argc-1 == i){             break;         }else{             cout << argv[i] <<endl;             cerr << "arguments error"<<endl;;             return 0;         }      } 

however program seems dump out arguments error message though outputs argv[i] = -1. 1 of things have tested though , should never have reached case. im sure syntax wise doing wrong.

edit

here imput sample error output.

user> ./colorfun -1 -c qc_bw.txt mountains.ppm      <-  9:46pm -1 arguments error 

it's c, can't compare strings str1 == "smth". use strcmp() instead.

more detailed explanations: operator == in c compares integral entities: numbers, pointers, etc. "smth" pointer memory area in constant segment of program. that's why code like

const char* = "abc"; const char* b = "abc"; assert(a == b); 

may give true, both & b may point single memory location. expression never compares letters "a", "b", "c" a , b, compares pointers. likewise in java have use str1.equals(str2) because java operator == compares integral entities (numbers, characters , "pointers objects"). in opposite in c++, python , other programming languages operator overloading, == 2 strings leads character character comparison.