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How do you redirect standard input to a file in the Windows command line?

Asked 2012-05-30T20:59:06.683
21

On Unix I would do something like:

cat > file.txt

How can I do this on the Windows command prompt or batch file?

EDIT: Basically, I am looking for the functionality of cat with no arguments (it reads from stdin and spits it back out to stdout).

batch-file cmd stdin cat
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1 Answer

13

If all you want is to read stdin and write what you read to stdout, then FINDSTR may work, depending on how you use it.

FINDSTR will output an exact binary image of the input as long as the input is specified as a single file name at the end of the argument list.

findstr "^" file.txt

Pipes or redirection may also work, depending on the content of the input:

findstr "^" < file.txt
or
type file.txt | findstr "^"

The output will be corrupted if any of the following occur while using redirected or piped input with FINDSTR:

  • Any input line > 8191 bytes
  • Last line of input is not terminated by \n. (command may hang if redirected input)

FINDSTR will not work if multiple input files are specified because in that case the name of the file will be used as a prefix to each line of output.

FINDSTR also differs from cat in that it cannot read from both stdin and a named file.

See What are the undocumented features and limitations of the Windows FINDSTR command? for more info.

answered 2012-05-30T22:10:22.597

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