Chrome extensions . Read or write files from the local hard disk.

Chrome extensions cannot directly read or write files from the local hard disk (HDD/SSD) for security reasons. However, there are workarounds depending on your needs.

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📌 What Chrome Extensions Can Do

1. Read user-selected files:

   • You can use the <input type="file"> element or the File API to allow users to select files manually.

   • Example: User selects a file, and your extension reads its contents.

2. Write files using downloads API:

   • You can create a file and let the user download it using chrome.downloads.download().

   • Example: Save extracted job titles to a .txt or .json file.

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🚫 What Chrome Extensions CANNOT Do

1. Directly access the file system like a regular app.

   • Extensions cannot read/write arbitrary files from C:\, /home/, etc.

2. Modify files on disk automatically.

   • You cannot edit an existing file on the HDD without user interaction.

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✅ Workarounds

Here’s how you can handle file operations:

1️⃣ Read a File (User Selects a File)

document.getElementById("fileInput").addEventListener("change", function(event) {
    let file = event.target.files[0]; // Get the selected file
    let reader = new FileReader();

    reader.onload = function(event) {
        console.log("File content:", event.target.result); // Process file data
    };

    reader.readAsText(file); // Read file as text
});

🔹 Requires <input type="file" id="fileInput"> in your popup.

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2️⃣ Write and Download a File

function downloadFile(content, filename) {
    let blob = new Blob([content], { type: "text/plain" });
    let url = URL.createObjectURL(blob);

    chrome.downloads.download({
        url: url,
        filename: filename,
        saveAs: true // Prompt user where to save
    });
}

// Example: Save extracted job titles
downloadFile("Sviluppatore\nPython Developer", "job_titles.txt");

🔹 Uses chrome.downloads.download() to create and save files.

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3️⃣ Use Native Messaging (Advanced)

🔹 If you really need full disk access, you must:

• Create a separate external program (Python, Node.js, etc.).

• Use Native Messaging API to communicate with it.

• The external program can read/write files freely.

📌 Example: Chrome Extension sends job titles → Python script saves to C:\data\jobs.txt.

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🚀 Conclusion

• 🔴 No direct HDD access.

• 🟢 Yes: Read user-selected files.

• 🟢 Yes: Save new files via chrome.downloads.

• 🟡 Advanced: Use Native Messaging for full access.