#include <stdio.h>
#include <string.h>

#define MAXLINE 1000

int getline(char *line, int max);

/* find: print lines that match pattern from first argument */

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

	char line[MAXLINE];
	long lineno = 0;
	int  c, except = 0, number = 0, found = 0;

	while ((--argc > 0) && ((*++argv)[0] == '-'))
		while (c = *++(argv[0]))
			switch (c)  {
			case 'x':
				except = 1;
				break;
			case 'n':
				number = 1;
				break;
			default:
				printf("find: illegal option %c\n", c);
				argc  =  0;
				found = -1;
				break;
			}
	if (argc != 1)
		printf("Usage: find -x -n pattern\n");
	else
		while (getline(line, MAXLINE) > 0)  {
			lineno++;
			if ((strstr(line, *argv) != NULL)  != except)  {
				if (number)
					printf("%ld:", lineno);
				printf("%s", line);
				found++;
			}
	}

	return found;
}


Note the difference between (*++argv)[0] and *++(argv[0]).