Wolfram Language & System 11.0 (2016)|Legacy Documentation

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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.
  • OpenRead[File["file"]] is also supported.

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 2016