sgrep.c

unix环境下实现的cmm语言编译器

int getline(char line[], int max);
int strindex(char source[], char searchfor[]);
int printf(char *fmt, char *);
int getchar();
char pattern[] = "ould";
int main(void)
{
	char line[512];
	int found = 0;

	while (getline(line, 512) > 0)
		if (strindex(line, pattern) >= 0) {
			printf("%s", line);
			found = found + 1;
		}
	return found;
}

/*strindex: 返回t在s中的位置，若未找至则返回-1*/
int strindex(char s[], char t[])
{
	int i, j, k;

	i = 0;
	while (s[i] != 0) {
		j = i;
		k = 0;
		while (t[k] != 0) {
			if (s[j] != t[k])
				break;
			j = j + 1;
			k = k + 1;
		}
		if (k > 0)
			if (t[k] == 0)
				return i;
		i = i + 1;
	}
	return -1;
}