使用fscanf()提取txt中一定格式的数据例子

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txt文本文件中的数据格式为如下：

[0.2942047,0.019607544,11.258041,24.22] [0.25497437,0.0,10.72847,32.00] [0.2745819,0.0,10.650024,40.21] [0.2745819,0.0,10.591187,48.43] [0.23536682,0.039230347,10.591187,57.02] [0.2942047,0.07846069,10.591187,65.43] [0.31381226,0.039230347,10.551956,73.80]

提取代码

#include <stdio.h>#include <vector>using namespace std;int extractDataFromTxt(const char* filename, int col){FILE* fp = fopen(filename, "r");if (!fp){perror("open file error");return -1;}float data[4] = {0};vector<float> res;while(fscanf(fp, "[%f,%f,%f,%f] ",&data[0], &data[1], &data[2], &data[3])> 0) // 注意每个"]"后跟有一个空格，同txt中格式保持一致{res.push_back(data[col]);}for (int i = 0; i < res.size(); i++){printf("%f\n", res[i]);}fclose(fp);return 0;}int main(int argc, char* argv[]){extractDataFromTxt(argv[1], 2); // 提取第二列数据return 0;}

打印输出为：

0 0