如果某个参数没有出现在命令行中，我该如何使它无法运行？

Question

I'm writing a program where I input range arguments at the command line and run a loop until it gets to the end of the range and then write them to a text file

./cmdline -b 100 -e 200 -s 4 -f text.txt -m w  // -b = beginning; -e = end; -s = step size; -f = file path; -m = mode
100 104 108 112 116 120 124 128 132 136 140 144 148 152 156 160 164 168 172 176 180 184 188 192 196 200

How do I make it so the program can't run if one of the range arguments, -b, -e, -s, are missing. Unless an r is written for the mode after the command is written to a text file, then it just reads the text file.

Answer 1

You can write the code below:

int main(int argc, char *argv[]) {
   if(argc != numbers_of_arguments) {
      printf("error message"); //a message you want
   }
   for(int i = 0; i < argc;) {
     if(strcmp(argv[i],"your range arguments") != 0) {
        printf("Error give these range arguments");
        return(-1);
     }
     i = i + 2; //cause of position of your range arguments
     if(i == 6) {
        break; // in order not proccess anything else because you reach your range arguments
     }
   }
   return(0);
}