im trying to find length of string but its producing wrong output how can i fix it

plus it gives me a warning i cant compare between pointer and zero character constant ?

#include pint main(int argc, char *argv[]) { int i = 0; printf("the tsring entered =%s ", argv[1]); while (argv[1] !='\0') { i++; argv++; } printf("Length of String : %d", i); return 0