Wolfram Language & System 10.0 (2014)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.View current documentation (Version 11.2)


opens a file to read data from, and returns an InputStream object.

Details and OptionsDetails and Options

  • OpenRead prepares to read from a file, starting at the beginning of the file.
  • On systems that support pipes, OpenRead["!command"] runs the external program specified by command, and opens a pipe to get input from it.
  • If OpenRead does not succeed in opening a particular file or pipe, it generates a message, and returns $Failed.
  • OpenRead resolves file names according to the procedure described in "Files and Streams".
  • The function ReadList automatically opens files or pipes that it needs.
  • OpenRead returns InputStream["name",n], where name is the full name of a file or command, and n is a serial number that is unique across all streams opened in the current Wolfram System session.
  • With the option BinaryFormat->True the stream is opened in binary format, so that no textual interpretation of newlines or other data is done.
  • With the Method option, the stream is opened using the given input stream method. This overrides the default way that OpenRead resolves file names.

ExamplesExamplesopen allclose all

Basic Examples  (1)Basic Examples  (1)

Open a file:

Click for copyable input

Read the file:

Click for copyable input
Click for copyable input
Click for copyable input

Close the stream:

Click for copyable input
Introduced in 1988
| Updated in 2012