C++ 格式读取文件中的参数

C++中格式读取文件中的参数

#Parameters

#sampling rate of frames(reference value:2-10)

samplingRate 2

#mode of feature extraction

videoSampleFeatureMode 13

videoSearchingFeatureMode 10

#/home/lumeiqi/projects/newVideoRetrieval   attention the enter key

videoPath  ../testvideo/test.mp4

#include "Parameters.h"
#include <fstream>
#include <string>
#include <sstream>
#include <stdexcept>
#include <iostream>

int Parameters::readParameters(const char *filename)
{
/*char buffer[2048];
char paramName[100];
int paramValue = 0;
char paramValuestr[100];*/
//避免使用C语言风格的字符数组，使用string，能省去很多问题
//使用stringstream和ifstream做流式读取会简单很多

stringstream buffer;
string line;
string paramName;
int paramValue = 0;
string paramValuestr;

ifstream fin(filename);
if (!fin.good())
{
string msg("parameters file not found");
msg.append(filename);
throw runtime_error(msg);
}
while (fin.good())
{
getline(fin,line);
if(line[0] != '#')
{
buffer << line;//order is important
buffer >> paramName;
if(paramName.compare("samplingRate") == 0)
{
buffer >> paramValue;
samplingRate = paramValue;
}
else if(paramName.compare("videoSampleFeatureMode") == 0)
{
buffer >> paramValue;
videoSampleFeatureMode = paramValue;
}
else if(paramName.compare("videoSearchingFeatureMode") == 0)
{
buffer >> paramValue;
videoSearchingFeatureMode = paramValue;
}
else if(paramName.compare("videoPath") == 0)
{
buffer >>paramValuestr;
videoPath = paramValuestr;
}
else{
throw runtime_error(string("unknown parameter: ").append(paramName));
}

}

}
fin.close();

}