程序员面试宝典(第三版)删除注释代码勘误

最近在看程序员面试宝典(第三版),发现p42,删除注释的代码有些问题,自己做了下修改如下：

void remove_comment(char buf[], int size)
{
    char *p, *end, c;
    char *sq_start, *dq_start;
    char *lc_start, *bc_start;
    int len;

    p = buf;
    end = p + size;
    sq_start = NULL;
    dq_start = NULL;
    lc_start = NULL;
    bc_start = NULL;

    while(p < end)
    {
        c = *p;
        switch(c)
        {
        case '\'':
            if (NULL != dq_start || NULL != lc_start || NULL != bc_start)
            {
                p++;
                continue;
            }
            if (sq_start == NULL)
            {
                sq_start = p++;
            }
            else
            {
                len = p++ - sq_start;
                if (len == 2 && *(sq_start + 1) == '\\')
                {
                    continue;
                }
                sq_start = NULL;
            }
            break;

            case '\"':
            if (NULL != sq_start || NULL != lc_start || NULL != bc_start)
            {
                p++;
                continue;
            }
            if (dq_start == NULL)
            {
                dq_start = p++;
            }
            else
            {
                len = p++ - dq_start;
                if (len == 2 && *(dq_start + 1) == '\\')
                {
                    continue;
                }
                dq_start = NULL;
            }
            break;

            case '/':
            if (NULL != sq_start || NULL != dq_start || NULL != lc_start || NULL != bc_start)
            {
                p++;
                continue;
            }
            c = *(p + 1);
            if ('/' == c)
            {
                lc_start = p;
                p += 2;
            }
            else if ('*' == c)
            {
                bc_start = p;
                p += 2;
            }
            else
            {
                p++;
            }
            break;

            case '*':
            if (NULL == bc_start)
            {
                p++;
                continue;
            }

            if (*(p + 1) != '/')
            {
                p++;
                continue;
            }
            p += 2;
            memset(bc_start, ' ', p - bc_start);
            bc_start = NULL;
            break;

            case '\n':
            if (lc_start == NULL)
            {
                p++;
                continue;
            }
            c = *(p - 1);
            memset(lc_start, ' ', (c == '\r' ? (p++ - 1) : p++) - lc_start);
            lc_start = NULL;
            break;
            default:
            p++;
            break;
        }
    }
}
int main()
{
    int fd,n;
    char buf[102400];

    fd=open("comment.c", O_RDONLY, 0);
    if (fd == -1)
    {
        return -1;
    }

    n=read(fd, buf, sizeof(buf));
    if (n<=0)
    {
        close(fd);
        return -1;
    }

    remove_comment(buf, n);
    *(buf+n)='\0';

          close(fd);
          return 0;
}

算法思路还是很清晰的，无非就是处理会影响注释的符号。处理单双引号是因为单双引号中的注释可忽略，处理换行符号，是因为行注释以行结尾作为结束。