Automating Routine with C++: Writing Scripts That Save Hours

Your C++ Isn't Just About Games and Drivers

When you hear "C++", you often imagine heavy artillery: Unreal engines, operating systems, high-load servers. But there's another, equally useful side — task automation in C++. While colleagues write one-off bash scripts or struggle with Python dependencies, you can build a compact, fast utility that will work for years without a single interpreter update.

In this article, I'll show you how to turn C++ into a Swiss Army knife for automation. We'll break down real examples: from batch file renaming to log parsing and report generation. You'll see that automating routine with C++ is not difficult, but very rewarding in terms of speed and reliability.

Why C++ Instead of Python or Bash?

Every language has its place. But there are scenarios where C++ has the edge:

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• Execution speed. If you're processing terabytes of logs — every millisecond counts.
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• No dependencies. A single statically compiled binary runs on any Linux/Windows without installing an interpreter.
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• Type safety. Fewer runtime surprises — critical for automation that runs on a schedule.
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• System access. Direct work with WinAPI, POSIX, the registry, processes — no layers in between.
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Of course, Python is more convenient for a quick prototype. But when a script becomes part of CI/CD or production infrastructure, automation in C++ pays off handsomely.

Toolkit: What You Need to Know

For our tasks, you don't need all of C++20. A basic set is enough:

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• std::filesystem (C++17) — working with files and folders
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• std::regex — text parsing
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• std::fstream / std::stringstream — reading/writing
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• std::chrono — time measurement and logging
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Compile with the flag -std=c++17 (or /std:c++17 for MSVC).

Example 1: Batch File Renaming

Imagine: you have a folder with photos IMG_001.jpg, IMG_002.jpg … You need to convert them to the format 2025_01_15_001.jpg. By hand — 10 minutes of tedious work. With a script — 0.2 seconds.

Code

#include <iostream>\n#include <filesystem>\n#include <regex>\n#include <string>\n\nnamespace fs = std::filesystem;\n\nint main() {\n    std::string dir_path = "./photos";\n    std::regex pattern(R"(IMG_(\\d+)\\.jpg)");\n    std::string prefix = "2025_01_15_";\n\n    for (auto &entry : fs::directory_iterator(dir_path)) {\n        std::string filename = entry.path().filename().string();\n        std::smatch match;\n\n        if (std::regex_match(filename, match, pattern)) {\n            std::string new_name = prefix + match[1].str() + ".jpg";\n            fs::rename(entry.path(), entry.path().parent_path() / new_name);\n            std::cout << "Renamed: " << filename << " -> " << new_name << "\\n";\n        }\n    }\n    return 0;\n}

This example shows how task automation in C++ using std::filesystem and regular expressions solves an everyday problem in just a few lines. You can easily adapt it to your own patterns.

Example 2: Log Parsing and Error Counting

Suppose a server writes logs in the format:

2025-01-15 10:23:45 [ERROR] Database connection failed\n2025-01-15 10:23:46 [INFO] Retry #1\n2025-01-15 10:23:47 [ERROR] Timeout exceeded

We need to collect statistics: how many errors of each type, and output the top 5 most frequent messages. A one-liner bash script can handle it, but if the logs are gigabytes — C++ will be many times faster.

Code

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