将文本文件C++从特定行分析到特定行

Parsing a text file C++ from specific line to specific line

本文关键字：文本 文件 C++      更新时间：2023-10-16

所以，我是 c++ 的新手。我的任务是解析文本文件，如下所示：

RE002%%
RE002%%
RE002%%
RE002%%
RE002%%
RE004%on%
$GPGGA,124749.80,5543.3227107,N,03739.1366738,E,1,08,1.11,147.9635,M,14.4298,M,,*5C
$GPGSV,3,1,10,27,13,078,43,05,31,307,48,16,24,042,43,02,10,267,43*7D
$GPGSV,3,2,10,26,03,031,36,07,75,215,51,09,57,121,53,30,40,234,50*76
$GPGSV,3,3,10,23,29,117,46,04,36,114,46*70
$GPGGA,124749.90,5543.3227105,N,03739.1366737,E,1,08,1.11,147.9664,M,14.4298,M,,*54
RE005%off%

它连续了几千行。我需要找到它写入 RE004%on% 的位置并开始处理此循环中的行，直到它找到 RE005%off% 并一遍又一遍地执行，直到文件结束。我试图用line.find来做这件事，但我很确定这是解决这个问题的错误方法

#include <iostream>
#include <fstream>
#include <string>
#include <stdlib.h>

using namespace std;


int main() {
string line, dollar, star, Checksum; 
float *t0 = NULL; 
int tount = 0;  
int k; 
ifstream logs_("C:/Users/Olya/Desktop/LogGLO.txt"); 
ofstream tout("outLOGTime.txt"); 
ofstream pout("outLOGPot.txt"); 
if (logs_.is_open()) 
{
while(getline(logs_,line))
{   
line.find("RE004%on%")
k = 0;
if 
dollar = line.find_first_of('$');
star = line.find_first_of('*');
Checksum = line.substr(line, dollar, star - dollar);
for (size_t i = 0; i < Checksum.size(); i++)
{
}

if (line.substr(0,6) == "$GPGSV") 
{
for (size_t i = 0, N = 7; i < line.size(); i++)
{
if (line[i] == ',') k++;
if(k == N)
{
pout << line.substr(i+1,2) << endl;
if ((N += 4) > 19) break;
}
}
}
logs_.close(); 
}
}
else 
cout<<"File is not open"<<'n';
tout.close(); 
pout.close(); 
return 0;
}

不幸的是，您的描述 si 非常不清楚。另外，通过阅读您的代码，我真的无法理解您的意图。您编辑了文本并更改了说明。对我来说没那么容易

但是，我做了一个有根据的猜测。

我读取您给定的分隔符之间的所有数据，验证校验和并将行拆分为标记。最后，我将所有带有令牌的行存储在一个向量中。然后我筛选一个特定的值并输出一列。

请学习并尝试理解。它并没有那么复杂。

谢谢

#include <iostream>
#include <regex>
#include <vector>
#include <iterator>
#include <string>
#include <utility>
#include <algorithm>
#include <functional>
#include <numeric>
#include <fstream>
const std::regex re{ R"($(.*)*[abcdefABCDEFd]{2})" };
const std::regex delimiter{ "," };
using Tokens = std::vector<std::string>;
std::tuple<bool, Tokens> checkString(const std::string& str) {
// Return value of the function. Assume that string is not ok
std::tuple<bool, std::vector<std::string>> result(false, {});
// We want to find a string in the given format
std::smatch sm{};
if (std::regex_match(str, sm, re)) {
// OK, found. Validate checksum
if (std::string s = sm[1];std::stoul(str.substr(str.size() - 2), nullptr, 16) == std::accumulate(s.begin(), s.end(), 0U, std::bit_xor<unsigned char>())) {
// Tokenize string
Tokens tokens(std::sregex_token_iterator(str.begin(), str.end(), delimiter, -1), {});
// Build return value
result = std::make_tuple(true, std::move(tokens));
}
}
return result;
}
int main() {
std::vector<Tokens> csvData{};
// Open file and check if it is open
if (std::ifstream logs("r:\LogGLO.txt"); logs) {
// Shall we process text lines or not
bool processingActive{ false };
// Read all lines of files
for (std::string line{}; std::getline(logs, line);) {
// Check, if we should start or stio processing of the lines
if (line.substr(0, 9) == std::string("RE004%on%")) processingActive = true;
if (line.substr(0, 10) == std::string("RE005%off%")) processingActive = false;
// Check and read csv data
if (processingActive) {
const auto [ok, data] = checkString(line);
if (ok) csvData.push_back(std::move(data));
}
}
}
// So, now we have read all csv data
// Show eight column of GPGSV data
for (const Tokens& t : csvData)
if (t[0] == "$GPGSV") 
std::cout << t[7] << "n";
return 0;
}
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