OpenRead ["file"]
opens a file to read data from, and returns an InputStream object.
OpenRead
OpenRead ["file"]
opens a file to read data from, and returns an InputStream object.
Details 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.
Examples
open all close allBasic Examples (1)
Open a file:
Read the file:
Close the stream:
Scope (1)
Open the file specified by the File object:
See Also
Tech Notes
Related Guides
History
Introduced in 1988 (1.0) | Updated in 1996 (3.0) ▪ 2007 (6.0) ▪ 2012 (9.0) ▪ 2016 (11.0)
Text
Wolfram Research (1988), OpenRead, Wolfram Language function, https://reference.wolfram.com/language/ref/OpenRead.html (updated 2016).
CMS
Wolfram Language. 1988. "OpenRead." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2016. https://reference.wolfram.com/language/ref/OpenRead.html.
APA
Wolfram Language. (1988). OpenRead. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/OpenRead.html
BibTeX
@misc{reference.wolfram_2025_openread, author="Wolfram Research", title="{OpenRead}", year="2016", howpublished="\url{https://reference.wolfram.com/language/ref/OpenRead.html}", note=[Accessed: 17-November-2025]}
BibLaTeX
@online{reference.wolfram_2025_openread, organization={Wolfram Research}, title={OpenRead}, year={2016}, url={https://reference.wolfram.com/language/ref/OpenRead.html}, note=[Accessed: 17-November-2025]}