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How to pass redirection characters (<and>) to a function of a Windows batch file?

Assume this batch file

 call :SomeFunction "a string with an > arrow" goto:eof :SomeFunction echo %~1 goto:eof

Result of this

  call: SomeFunction "a string with an> arrow"
 echo a string with an 1> arrow
 goto: eof
 goto: eof

and a file called arrow is created that contains a string with an . Pay attention to 1> .

How can I prevent the shell from interpreting > as a redirection character in this situation? (Hint: I tried ^> and it is not.)

EDIT: Of course, other operators ( | and & ) also influence.

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3 answers

To do this, you can use the FOR /F command, and not:

 echo %~1

Use this:

 FOR /F "delims=" %%i IN ("%~1") DO echo %%i

Edit: note that now you need to deal with strange escaping behaviors when passing an argument separated by double quotes. For example, "a^2" will be escaped as "a^^2" , it does not matter if you try using "a^^2" or "a\^2" . What you can do (according to your own comment) is to use a temporary variable and do the escaping (then remove the double quotes):

 set TEMP=%TEMP:>=^>%

If you don't want to worry about escaping, you can also try:

 set "tmp="many \ ^ > ' characters and quotes""

Pay attention to double quotes to enclose the set argument and many special characters in the string. In this case, the tmp environment variable will be literally: "many \ ^ > ' characters and quotes" , you can simply use it as:

 FOR /F "delims=" %%1 IN (%tmp%) DO echo %%1

Note %1 instead of "%~1" . Let's complicate the situation now. If you need a double quote " , then some characters will not be escaped (for example, & and | ). You can simply remove the quote:

 set "tmp=many \ ^ > ' | & characters and quotes"

B:

 FOR /F "delims=" %%1 IN ("%tmp%") DO echo %%1

or

 FOR /F "delims== tokens=2" %%1 IN ('set tmp') DO echo %%1

Remember that you can use hints to delimit the FOR line if you specify the usebackq option. You can use a temporary file or ... better ... PowerShell script ...

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Call makes funky with ^ , but it works.

 @echo off set "var=a string with an ^> arrow" call :SomeFunction pause goto:eof :SomeFunction echo %var% goto:eof
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As the name says foxidrive, CALL modifies the carriage, so it’s not possible to create a bulletproof way to pass parameters by value via CALL.
But instead, you can use the options by reference.

 @echo off set "var=a string with a caret^ and an > arrow" call :SomeFunc var exit /b :SomeFunc setlocal EnableDelayedExpansion set "param1=!%1!" echo !param1! exit /b

I am using a delayed extension here, as this is the best way to safely handle any variable contents.

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