根据输入字符结束数组输入

用 realloc() ，下面是实现代码作参考

 #include <stdio.h>
#include <malloc.h>

int main(void)
{
    char *p = NULL, *p1 = NULL, c;
    int count = 0, i = 0, size = 100;

    if(!(p = (char *)malloc(size)))
        return 0;

    while('0' != (c = getchar()))
    {
        if(count < 100)
        {
            p[i] = c;
        }
        else
        {
            size += 100;
            p1 = (char *)realloc(p, size);
            if(!p1)
            {
                break;
            }
            else
            {
                p = p1;
            }

            p[i] = c;
            count = 0;
        }

        count++;
        i++;
    }

    free(p);
    return 0;
}