I have a node.js server (express.js) and I have a json file that I use to read and write data (simple api). When the node.js server is stopped, that other application adds data to the json file without any problems. When the node.js server is started that other application sees that json file as an empty file, probably because the node.js server keeps it open. In node.js I use fs.readFile and it closes the json file after reading, so I don't think that's the problem. All this is happening on a local windows machine. Has anyone had a similar problem sharing a single file with node.js and some other application? If anyone had a direction to guide me, where to look for a solution.

Thank you for your time!

@jfriend00 As for that other application, it was written in clarion and I don't have access at the moment. That application rarely writes data to that file. Here's how I read and write the file:

function load(fileName, path, callback) {    
    let jsonPath = "";
    if(fileName == "companies") {
        jsonPath = __dirname + "\\..\\..\\";
    } else {
        jsonPath = path;
    }    
    fs.readFile(jsonPath + fileName.toUpperCase() + '.JSON', function (err, data) {    
        if (err) {
            if (err.code === "ENOENT") {                
                console.log("File '" + fileName.toUpperCase() + ".JSON' not found!");
                callback([]);
                return;
            } else {
                throw err;
            }
        }
        callback(JSON.parse(data.toString()));
    });
} 


function save(fileName, path, array) {
    let jsonPath = "";
    if(fileName == "companies") {
        jsonPath = __dirname + "\\..\\..\\";
    } else {
        jsonPath = path;
    } 
    fs.writeFile(jsonPath + fileName.toUpperCase() + '.JSON', JSON.stringify(array), function (err) {
        if (err) {
            throw err;
        }
    });
}