File Handling

BoxLang allows you to manipulate, read, upload, and more files via its built-in methods, which are great and easy to use. It can even help you manipulate zip/jar archives! We won't go into every single detail of file handling, but below, you can find the majority of functions to handle file handling.

• DirectoryCopy Copies the contents of a directory to a destination directory.

• DirectoryCreate Creates a new directory for the specified path

• DirectoryDelete Deletes directory for a given path

• DirectoryExists Determines whether a directory exists.

• DirectoryList Lists the directory and returns the list of files under it as an array or query

• DirectoryRename Renames given directory

• ExpandPath Creates an absolute, platform-appropriate path that is equivalent to the value of relative_path, appended to the base path. This function (despite its name) can accept an absolute or relative path in the relative_path attribute

• FileAppend appends the entire content to the specified file.

• FileClose Closes an open file.

• FileCopy Copies the specified on-disk or in-memory source file to the specified destination file.

• FileDelete Deletes the specified file on the server.

• FileExists Determines whether a file exists

• FileGetMimeType Returns the mime type of the given file

• FileInfo returns detailed info about the given file.

• FileIsEOF Determines whether BoxLang has reached the end of the file while reading it.

• FileMove Moves file from source to destination

• FileOpen Opens a file to read, write, or append.

• FileRead Reads an on-disk or in-memory text file or a file object created with the FileOpen function.

• FileReadLine Reads a line from a file.

• FileSeek Shifts the file pointer to the given position. The file must be opened with the seekable option

• FileSetAccessMode This function sets the attributes of an on-disk file on UNIX or Linux. It does not work with in-memory files.

• FileSetAttribute For the given path, set the file attributes.

• FileSetLastModified For the given file, set the last modification date

• FileSkipBytes Shifts the file pointer by the given number of bytes.

• FileTouch Touches the given file and creates it if it does not already exist.

• FileUpload Uploads a file to a directory on the server.

• FileUploadAll Uploads files to a directory on the server.

• FileWrite If you specify a file path, it writes the entire content to the specified file. If you specify a file object, it writes text or binary data to the file object.

• FileWriteLine Opens up the file (or uses the existing file object) and appends the given line of text

• GetFileInfo Retrieves file information.

• GetFreeSpace Returns the number of unallocated bytes in the partition named by this abstract path name.

• GetTempDirectory Returns the full path to the currently assigned temporary directory

• GetTempFile Creates a temporary file in a directory whose name starts with (at most) the first three characters of the prefix.

• ImageWrite Writes an image to the specified filename or destination.

// A few examples
content = fileRead( expandPath( "/config/myfile.txt" ) );
if( fileExists( "filepath.txt" ) ){

}
fileDelete( "filepath.txt" )
fileWrite( getTempFile( getTempDirectory(), "tempFile"), "My Data" );

directoryList( "/my/path" )
directoryExists( "/my/path" )

<form method="post" enctype="multipart/form-data">
  <input type="file" name="fileInput">
  <button type="submit">Upload</button>
</form>

<bx:script>
  if( structKeyExists( form, "fileInput" )) {
    try {
      uploadedFile = fileUpload( getTempDirectory(), "fileInput", "image/jpeg,image/pjpeg", "MakeUnique" );
      // check the file extension of the uploaded file; mime types can be spoofed
      if (not listFindNoCase("jpg,jpeg", uploadedFile.serverFileExt)) {
      throw("The uploaded file is not of type JPG.");
      }
      // do stuff with uploadedFile...
    } catch ( e ) {
      writeOutput( "This upload form only accepts JPEG files." );
    }
    catch (any e) {
      writeOutput( "An error occurred while uploading your file: #e.message#" );
    }
  }
</bx:script>

Dealing With Large Files

If you want to read or manipulate large files, we recommend leveraging our cbStreams library or native Java file streaming. Below, you can find some sample usage of reading large files with cbStreams, which implements the Java Streams API.

stream = streamBuilder.new().ofFile( absolutePath );
try{
    //work on the stream of lines of files and close it in the finally block
} finally{
    stream.close();
}

//You can even process file lines concurrently
stream = streamBuilder.new()
    .parallel()
    .ofFile( absolutePath );