Comparing command parameter with argv[] is not working

Question

I am trying to compare the parameter of command with argv[] but it\'s not working. Here is my code.

./a.out -d 1

In main function

Answer 1

You can't compare strings using ==. Instead, use strcmp.

#include 

int main (int argc, char * const argv[]) {

if (strcmp(argv[1], "-d") == 0)

// call some function here

}

The reason for this is that the value of "..." is a pointer representing the location of the first character in the string, with the rest of the characters after it. When you specify "-d" in your code, it makes a whole new string in memory. Since the location of the new string and argv[1] aren't the same, == will return 0.