????? ?? JavaScript? ?? MIME ??? ???? ??? ??????

? ??? ??? ?? ???? ? ??????? ?? ??? ?????. ???? ??? MIME ??? ???? ??? ???? ???? ???? ??? ??? ???? ?? ?????.

?? ????? ???? JavaScript? ???? ????? ??? ?? MIME ??? ?? ??? ? ????. ? ????? ???? ??? ?? ???? ?? ??? ???? ???? ??? ??? ??? ???????.

?? ??

??? ???? ?? ?? ??? ????. ?? ? Blob API? JavaScript?? ??? ???? ? ??????. ?????? ??? API? ?? ?????? ??? ?????.

1??: ?? ?? ??

??? ??? ?? ??? ????? ?? ??? ??? ? ????.

var input = document.getElementById("file-input");

input.addEventListener("change", function(e) {
  var files = e.target.files;
  
  // Iterate through the files
  for (var i = 0; i < files.length; i++) {
    console.log("Filename: " + files[i].name);
    console.log("Type: " + files[i].type);
    console.log("Size: " + files[i].size + " bytes");
  }
});

2??: MIME ?? ??

MIME? ???? ?? ? ?? ?? ??? ????. ??:

• ?? ??: JavaScript Blob ??? ????? MIME ?? ??? ?????:

var blob = files[i]; // File from Step 1
console.log(blob.type);

• ?? ?? ??: ?? ???? ?? ??? ?? ??? ??? ? ????. ??:

var blob = files[i]; // File from Step 1
var fileReader = new FileReader();

fileReader.onloadend = function(e) {
  var header = "";
  
  // Extract the first four bytes of the file
  var arr = (new Uint8Array(e.target.result)).subarray(0, 4);
  for (var i = 0; i < arr.length; i++) {
    header += arr[i].toString(16);
  }
  
  console.log(header);
};

fileReader.readAsArrayBuffer(blob);

????, ??? ??? ??? ?? ??? ???? MIME ??? ???? ???.

?? ?? ??

MIME ??? ???? ?? ??? ??? ?? ?? ???? ????? ??? ? ????. ??.

?? ????

??? ??? ???? ?? ?? ?? ??? ?????.

// Get file header
function getFileHeader(blob, callback) {
  var fileReader = new FileReader();
  fileReader.onloadend = function(e) {
    var arr = (new Uint8Array(e.target.result)).subarray(0, 4);
    var header = "";
    for (var i = 0; i < arr.length; i++) {
      header += arr[i].toString(16);
    }
    callback(header);
  };
  fileReader.readAsArrayBuffer(blob);
}

// Determine MIME type
function getMimeType(header) {
  switch (header) {
    case "89504e47":
      return "image/png";
    case "47494638":
      return "image/gif";
    case "ffd8ffe0":
    case "ffd8ffe1":
    case "ffd8ffe2":
      return "image/jpeg";
    default:
      return "unknown";
  }
}

// Handle file selection
document.getElementById("file-input").addEventListener("change", function(e) {
  var file = e.target.files[0];
  getFileHeader(file, function(header) {
    var mimeType = getMimeType(header);
    console.log("File: " + file.name);
    console.log("MIME Type: " + mimeType);
  });
});

?????? MIME ?? ??? ??

1. ?? ?? ??: ???? ?? ??? ?????. ??? ??.
2. ??? ??? ??: ???? ?? ?? ???? ?? ???? ??? ?? ???? ??? ?????.
3. ??? ?? ??? ??: ??? ????? ?????. ?? ???? ?? ?? ? ??? ???

??

JavaScript? ????? ??? ?? MIME ??? ???? ???? ??? ???? ?? ? ??? ??? ?????. File ? Blob API? ???? ???? ??? MIME ??? ????? ???? ? ??????? ??, ??? ? ??? ??? ???? ? ????.

? ??? ??? ????? ?? JavaScript? ???? ??? MIME ??? ??? ??? ? ????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!