fs.readFile works, but readFileSync returns empty content












0















The following block of code leaves the content variable empty:



const file = fs.createWriteStream("/home/pi/rpi-main/descriptor.json");



http.get(url, function (response) {

    let content;



    response.pipe(file);

    content = fs.readFileSync("/home/pi/rpi-main/descriptor.json", { encoding: "utf-8" });

});


However, if I read the file using fs.readFile, the content is what it should be.



Why is this happening with the synchronous call?






node.js fs







share|improve this question


















  • 1





    Where in your code are you using content?

    – Kevin B
    Nov 21 '18 at 17:58
















0















The following block of code leaves the content variable empty:



const file = fs.createWriteStream("/home/pi/rpi-main/descriptor.json");



http.get(url, function (response) {

    let content;



    response.pipe(file);

    content = fs.readFileSync("/home/pi/rpi-main/descriptor.json", { encoding: "utf-8" });

});


However, if I read the file using fs.readFile, the content is what it should be.



Why is this happening with the synchronous call?






node.js fs







share|improve this question


















  • 1





    Where in your code are you using content?

    – Kevin B
    Nov 21 '18 at 17:58














0












0








0








The following block of code leaves the content variable empty:



const file = fs.createWriteStream("/home/pi/rpi-main/descriptor.json");



http.get(url, function (response) {

    let content;



    response.pipe(file);

    content = fs.readFileSync("/home/pi/rpi-main/descriptor.json", { encoding: "utf-8" });

});


However, if I read the file using fs.readFile, the content is what it should be.



Why is this happening with the synchronous call?






node.js fs







share|improve this question














The following block of code leaves the content variable empty:



const file = fs.createWriteStream("/home/pi/rpi-main/descriptor.json");



http.get(url, function (response) {

    let content;



    response.pipe(file);

    content = fs.readFileSync("/home/pi/rpi-main/descriptor.json", { encoding: "utf-8" });

});


However, if I read the file using fs.readFile, the content is what it should be.



Why is this happening with the synchronous call?






node.js fs




node.js fs






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 21 '18 at 17:35









Andrei OnigaAndrei Oniga

3,12883875




3,12883875








  • 1





    Where in your code are you using content?

    – Kevin B
    Nov 21 '18 at 17:58














  • 1





    Where in your code are you using content?

    – Kevin B
    Nov 21 '18 at 17:58








1




1





Where in your code are you using content?

– Kevin B
Nov 21 '18 at 17:58





Where in your code are you using content?

– Kevin B
Nov 21 '18 at 17:58












1 Answer
1






active

oldest

votes


















1














It's because pipe is an async function, so when you call readFileSync it actually hasn't begun writing anything to the file.



You should read your file in the callback for the finish event of the pipe.



response.pipe(file).on('finish', () => {

    content = fs.readFileSync(filename, { encoding: "utf-8" });

});





share|improve this answer
























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    1 Answer
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    active

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    active

    oldest

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    1














    It's because pipe is an async function, so when you call readFileSync it actually hasn't begun writing anything to the file.



    You should read your file in the callback for the finish event of the pipe.



    response.pipe(file).on('finish', () => {
    
    content = fs.readFileSync(filename, { encoding: "utf-8" });
    
});





    share|improve this answer




























      1














      It's because pipe is an async function, so when you call readFileSync it actually hasn't begun writing anything to the file.



      You should read your file in the callback for the finish event of the pipe.



      response.pipe(file).on('finish', () => {
      
    content = fs.readFileSync(filename, { encoding: "utf-8" });
      
});





      share|improve this answer


























        1












        1








        1







        It's because pipe is an async function, so when you call readFileSync it actually hasn't begun writing anything to the file.



        You should read your file in the callback for the finish event of the pipe.



        response.pipe(file).on('finish', () => {
        
    content = fs.readFileSync(filename, { encoding: "utf-8" });
        
});





        share|improve this answer













        It's because pipe is an async function, so when you call readFileSync it actually hasn't begun writing anything to the file.



        You should read your file in the callback for the finish event of the pipe.



        response.pipe(file).on('finish', () => {
        
    content = fs.readFileSync(filename, { encoding: "utf-8" });
        
});






        share|improve this answer












        share|improve this answer



        share|improve this answer










        answered Nov 22 '18 at 8:34









        mihaimihai

        24.7k74169




        24.7k74169
































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