[C语言]在终端输入多行信息，找出包含“ould”的行，并打印改行

#define _crt_secure_no_warnings 1
#include<stdio.h>
#include<assert.h>
#include<stdlib.h>
#define max 1000
 
char *my_strstr(const char *dst,const  char *src)
{
    assert(dst);
    assert(src);
    char *p = dst;
    char *s1 = p;
    char *s2 = src;
    while (*s1)
    {
        s1 = p;
        s2 = src;
        while ((*s1!='\0')&&(*s2 != '\0'))
        {
            if (*s1++ == *s2++)
            {
                ;
            }
            else
            {    
                p++;
                break;
            }
        }
        if (*s2 == '\0')
        {
            return p;
        }
    }
    return null;
}
int getline(char *line, int limit)
{
    assert(line);
    char ch = 0;
    int i = 0;
    while (limit-- && ((ch = getchar()) != eof) && ch != '\n')
    {
        line[i++] = ch;
    }
    if (ch == '\n')
    {
        line[i++] = '\n';
    }
    line[i] = '\0';
    return i;
}
int main()
{
    /*char *str1 = "abbbcdef";
    char *str2 = "bbcd";
    char *ret = my_strstr(str1, str2);
    printf("%s\n", ret);*/
    char *str1 = "ould";
    char line[max] = { 0 };
    while (getline(line, max - 1))
    {
        if (my_strstr(line, str1))
        {
            printf("%s\n", line);
        }
    }
    system("pause");
    return 0;
}