vfs.reader

function

Library: File system utilities (OMVFS)
Import : omvfs.xmd

Returns: An OmniMark source object to the opened file

Declaration

export external string source function reader
        of      value file file-ref

Argument definitions

file-ref: The vfs.file object associated with the file to be read from.

Purpose

You can use vfs.reader to read the contents of a file opened with vfs.open. vfs.reader returns an OmniMark source attached to the specified file.

  import "omvfs.xmd" prefixed by vfs.
  
  process
    local vfs.file test-file
     set test-file to vfs.open "/programs/test.txt" 
      for vfs.read-mode
    submit vfs.reader of test-file

You can also read a file using OmniMark's built in file keyword, but using vfs.file gives you greater control over how the file is opened and read.

Exceptions

The following exceptions may occur:

VFS200 The vfsFile object must be opened before it can be used
VFS204 The file 'X' must not have an active output or source associated with it
VFS207 The file 'X' must be opened with read access to enable reading from it
VFS217 The function timed out before the lock could be obtained on 'X'
VFS300 Generic operating system error