Question

我有一个从文本文件中提取某些数据并显示输出的代码，该代码功能齐全并提供正确的输出。现在我希望该输出自动保存在文本文件中。那我该怎么做呢？有人可以帮忙吗？

我无法添加代码，因为每次“看起来您的帖子大部分都是代码；请添加更多详细信息”时，都会出现此错误。

#include <iostream>
#include <iomanip>
#include <fstream>
#include <string>
#include <vector>
#include <cctype>

// true if line begins with s, but ignoring spaces
bool is_match(const std::string& line, const std::string& s) {
size_t i = 0, j = 0;
for (;;) {
    while (i < line.size() && isspace(line[i]))
        ++i;
    if (i >= line.size())
        break;
    while (j < s.size() && isspace(s[j]))
        ++j;
    if (j >= s.size())
        break;
    if (line[i++] != s[j++])
        return false;
}
return j == s.size();
}

int main() {
std::vector<std::string> titles {
    "Subscriber number",
    "Termination ID",
    "Equipment ID",
    "AGCU module number",
    "Master/Slave type"
};

std::ifstream fin("LST_IMSBR.txt");
if (!fin) {
    std::cerr << "Cannot open input file.\n";
    return 1;
}

std::string line;

std::cout << "|Subscriber number"
             "|Termination ID"
             "|  Equipment ID  "
             "|AGCU module number"
             "|Master/Slave type|\n";

while (std::getline(fin, line)) {

    std::vector<std::string> values(titles.size());
    bool found = false;

    while (std::getline(fin, line)) {
        if (line.substr(0, 3) == "+++")
            break;

        for (size_t i = 0; i < titles.size(); ++i) {
            if (is_match(line, titles[i])) {
                size_t pos = line.find('=');
                if (pos < line.size()) {
                    pos = line.find_first_not_of(" ", pos + 1);
                    if (pos < line.size()) {
                        found = true;
                        values[i] = line.substr(pos);
                    }
                }
            }
        }
    }
    auto sw = std::setw;
    if (found) {
        std::cout << '|'    << sw(11) << values[0] << "      |";
        std::cout << "   "  << sw( 4) << values[1] << "       |";
        std::cout           << sw(16) << values[2] << "|";
        std::cout           << sw( 8) << values[3] << "          |";
        std::cout << "    " << std::left << sw( 6) << values[4]
                            << std::right << "       |\n";
    }
}
}

Answer 1

您可以使用输出重定向到文件：

./a.out > ./a.log

Answer 2

如果您的代码在控制台上可以正常工作，则可以更改最后一个if语句，我会考虑将for(;;)更改为while(true)。删除：

std::cout << "|Subscriber number"
             "|Termination ID"
             "|  Equipment ID  "
             "|AGCU module number"
             "|Master/Slave type|\n";

编辑if语句。

if (found) {
   std::ofstream ostrm("exaple.txt");
   ostrm << "|Subscriber number"
             "|Termination ID"
             "|  Equipment ID  "
             "|AGCU module number"
             "|Master/Slave type|\n";
   ostrm << '|' << sw(11) << values[0] << "      |"
            << "   " << sw(4) << values[1] << "       |"
            << sw(16) << values[2] << "|"
            << sw(8) << values[3] << "          |"
            << "    " << std::left << sw(6) << values[4]
            << std::right << "       |\n";
   ostrm.close();
}

如何在C ++中将输出保存到.txt文件

2 个答案: