Read and write text example in Adobe extendscript

Read and write text.jsx

// In this demo: 
// 1. I first prep the output file path
// 2. Then write the text file: "current date and time + some placeholder text"
//    - As long as you don't change the path, it gets written next to this script file.
// 3. Then read the text file
// 4. And finally trigger alert() to show the text that was written.
//    - At the top it shows each line as an array
//    - And below that it just shows the full text as it was written.

// Preparing output path
var scriptFolder = File.decode( File($.fileName).parent );
var file = scriptFolder + "/Read and write text.txt";

// Writing
var date = new Date();
writeTextFile( file, date + ' Suspendisse ut tortor sapien. \r\n\r\nAenean vitae magna tempus, fermentum.' );

// Reading
var textLines = [];
var fullText = readTextFile( file, function( line, i ) {
  textLines.push( line );
});

alert( textLines.toSource() + '\n\n' + fullText  );

// ↑↑↑ USAGE EXAMPLES ↑↑↑ 





// Returns all of the text as is
// Returns false if the file doesn't exist
// Callback is triggered for each line of text
function readTextFile( filePath, callback ) {
  
  var file = new File( filePath );
  if ( file.exists ) {
    
    file.open('r');
    file.encoding = 'UTF8';
    var text = file.read();
    file.close(); 
    
    var lines = text.match(/\\r\\n/) ? text.split('\r\n') : text.match(/\\r/) ? text.split('\r') : text.split('\n');
    if ( typeof callback == 'function' ) {
      for ( var i=0; i < lines.length; i++ ) {
        callback( lines[i], i );
      }
    }
    
    return text;
    
  }
  else {
    return false;
  }
  
}

// Set the third parameter to true if you don't want this to create the file if it doesn't already exist.
// Returns false if file was not created. Doesn't account for write errors...
function writeTextFile( filePath, textContent, dontCreateFile ) {
  
  var file = new File( filePath );
  var fileExists = file.exists;
  if ( fileExists || !fileExists && dontCreateFile !== true ) {
    
    file.open('w'); // Opens a file for writing. If the file exists, its contents are destroyed. If the file does not exist, creates a new, empty file.
    file.encoding = 'UTF8';
    file.write( textContent );
    file.close();
    
  }
  else {
    return false;
  }
  
}