在这段C++程序里，调试时会提示如下错误：

Question

int read_input_string(char *filename, char *entry, char **data, int num)
{
ifstream ifp(filename);
char buffer[256];
int entry_len = strlen(entry);
int i, flag, idx, count = 0;
while (ifp.getline(buffer, 256) != NULL)
{
int buffer_len = strlen(buffer);
if (buffer_len >= entry_len)
{
flag = 1;
for (i = 0; i<entry_len; i++)
if (buffer[i] != entry[i]) flag = 0;
if (flag == 1)
{
while (buffer[i] != '=' && buffer[i] != '\0')
i++;
if (buffer[i] != '\0') i++;
while (buffer[i] == ' ' && buffer[i] != '\0')
i++;
count = 0;
idx = 0;
for (int j = i; j <= buffer_len; j++)
{
if (buffer[j] == ' ' || j == buffer_len)
{
if (idx != 0)
{
data[count][idx] = '\0';
idx = 0;
count++;
if (count == num) break;
}
}
else
data[count][idx++] = buffer[j];
}
}
}
}
if (count < num)
return -1;
else
return 0;
}
在这段C++程序里，调试时会提示如下错误：
IntelliSense: 没有与这些操作数匹配的 "!=" 运算符
操作数类型为: std::basic_istream<char, std::char_traits<char>> != int
希望各位高手帮忙看看该怎么修改？

Answer 1

while (ifp.getline(buffer, 256) != NULL)这行改成ifp.getline(buffer,&nbsp;256);while&nbsp;(ifp.good()){&nbsp;&nbsp;&nbsp;&nbsp;//....&nbsp;&nbsp;&nbsp;&nbsp;//...&nbsp;&nbsp;&nbsp;&nbsp;ifp.getline(buffer,&nbsp;256);}因为getline函数返回的是ifp对象本身的应用，而不是读取到的字符数。