在读取配置文件时，window环境下，有GetProfileString函数，而Linux下则没有。我写了一个能实现其功能的函数，如下所示，基本思想是捉住配置文件中用“[]”标记的段没有“=”，而非“[]”段有“=”这一特征，先找section段，再找键，得到对应的值。不当之处，欢迎批评指正。
配置文件示例
[section1] age = 12 name = edward [section2] age = 13 name = lewis
代码示例
#include "cstdio"
#include "iostream"
#include "string"
#include "fstream"
using namespace std;
const int OP_SUCCESS = 0;
const int OP_FAILED = -1;
int GetProfileString(string file_name, string section_name, string item_name, string &item_value)
{
ifstream mystream;
mystream.open(file_name.c_str(), ios::in);
if (!mystream)
{
cout << "Error " << endl;
return -1;
}
char line[30];
string line2;
size_t return_of_find;
bool found = false;
while(mystream.getline(line, 30) && !found) //默认行不会超过30个字符
{
line2 = line;
return_of_find = line2.find(section_name);
if (string::npos == return_of_find)
{
continue; //没找到section项，则继续下一行读取
}
//找到了，则执行第二步，寻找相应的键值，关键是不能跨越多段
while(mystream.getline(line, 30) && !found)
{
line2 = line;
string equal_flag = "=";
return_of_find = line2.find(equal_flag);
if (string::npos == return_of_find)
{
//说明已经跨越了多段，目标寻找失败
return -1;
}
//还在当前段中
return_of_find = line2.find(item_name);
if (string::npos == return_of_find)
{
//没有找到
continue;
}
//找到了
return_of_find = line2.rfind(" "); //要求配置文件=两边要有空格
item_value = line2.substr(return_of_find + 1);
found = true;
if (' ' == item_value[0])
{
item_value = item_value.substr(1);
}
}
}
mystream.close();
return 0;
}
int main(int argc, char* argv[])
{
string file_name, section_name, item_name, item_value;
file_name = "F:\\test.txt";
section_name = "section2";
item_name = "age";
GetProfileString(file_name, section_name, item_name, item_value);
cout << item_value << endl;
return 0;
}
