How do you strip quotes out of an ECHO'ed string in a Windows batch file?

Question

I have a Windows batch file I'm creating, but I have to ECHO a large complex string, so I'm having to put double quotes on either end. The problem is that the quotes are also being ECHOed to the file I'm writing it to. How do you ECHO a string like that and strip the quotes off?

UPDATE:

I've spent the last two days working on this and finally was able to kludge something together. Richard's answer worked to strip the quotes, but even when I put the ECHO in the subroutine and directly outputted the string, Windows still got hung up on the chars in the string. I'll accept Richard's answer since it answers the question asked.

I ended up using Greg's sed solution, but had to modify it because of sed/windows bugs/features (it didn't help that it came with no documentation). There are a few caveats to using sed in Windows: you have to use double quotes instead of single quotes, you can't escape the double quotes in the string directly, you have to endquote the string, escape using the ^ (so ^") then beqin quote for the next section. Also, someone pointed out that if you pipe input to sed, there's a bug with a pipe being in the string (I didn't get to verify this since in my final solution, I just found a way not to have all quotes in the middle of the string, and just removed all quotes, I never could get the endquote to be removed by itself.) Thanks for all the help.

Solution 1

The call command has this functionality built in. To quote the help for call:

 Substitution of batch parameters (%n) has been enhanced.  You can
 now use the following optional syntax:

 %~1         - expands %1 removing any surrounding quotes (")

Here is a primitive example:

@echo off
setlocal
set mystring="this is some quoted text"
echo mystring=%mystring%
call :dequote %mystring%
echo ret=%ret%
endlocal
goto :eof

:dequote
setlocal
rem The tilde in the next line is the really important bit.
set thestring=%~1
endlocal&set ret=%thestring%
goto :eof

Output:

C:\>dequote
mystring="this is some quoted text"
ret=this is some quoted text

I should credit the 'environment variable tunneling' technique (endlocal&set ret=%thestring%) to Tim Hill, 'Windows NT Shell Scripting'. This is the only book I have ever found that addresses batch files with any depth.

Solution 2

The following approach can be used to print a string without quotes:

echo|set /p="<h1>Hello</h1>"

pushing this string into file:

echo|set /p="<h1>Hello</h1>" > test.txt

pushing this string into file and appending a CR/LF:

echo|(set /p="<h1>Hello</h1>" & echo.) > test.txt`

To check:

type test.txt

Solution 3

You can use the %var:x=y% construction that replaces all x with y.

See this example what it can do:

set I="Text in quotes"
rem next line replaces " with blanks
set J=%I:"=%
echo original %I%
rem next line replaces the string 'in' with the string 'without' 
echo stripped %J:in=without%

Solution 4

To remove all quotation marks from a set variable, you need Delayed Variable Expansion to securely expand the variable and process it. Expansion using percent signs (i.e. %VAR% and %1) are inherently unsafe (they are vulnerable to command injection; read this for details).

SETLOCAL EnableDelayedExpansion
SET VAR=A ^"quoted^" text.
REM This strips all quotes from VAR:
ECHO !VAR:^"=!
REM Really that's it.

To strip quotes from a text file or a command output, things will get complicated because with Delayed Expansion, string like !VAR! within the text document will get expanded (within the %%i expansion in FOR /F) when it shouldn't. (This is another vulnerability—information disclosure—that's not documented elsewhere.)

To safely parse the document, a switch between delayed-expansion-enabled and -disabled environment is needed.

REM Suppose we fetch the text from text.txt

SETLOCAL DisableDelayedExpansion
REM The FOR options here employs a trick to disable both "delims"
REM characters (i.e. field separators) and "eol" character (i.e. comment
REM character).
FOR /F delims^=^ eol^= %%L IN (text.txt) DO (

    REM This expansion is safe because cmd.exe expands %%L after quotes
    REM parsing as long as DelayedExpansion is Disabled. Even when %%L
    REM can contain quotes, carets and exclamation marks.
    SET "line=%%L"

    CALL :strip_quotes
    REM Print out the result. (We can't use !line! here without delayed
    REM expansion, so do so in a subroutine.)
    CALL :print_line
)
ENDLOCAL
GOTO :EOF

REM Reads !line! variable and strips quotes from it.
:strip_quotes
    SETLOCAL EnableDelayedExpansion
    SET line=!line:^"=!

    REM Make the variable out of SETLOCAL
    REM I'm expecting you know how this works:
    REM (You may use ampersand instead:
    REM `ENDLOCAL & SET "line=%line%"`
    REM I just present another way that works.)
    (
    ENDLOCAL
    SET "line=%line%"
    )
GOTO :EOF

:print_line
    SETLOCAL EnableDelayedExpansion
    ECHO !line!
    ENDLOCAL
GOTO :EOF

The delims^=^ eol^= in the code above probably needs explanation: This effectively disables both "delims" characters (i.e. field separators) and "eol" character (i.e. comment character). Without it, the "delims" will default to tab and space and "eol" defaults to a semicolon.

• The eol= token always read whichever the next character it is after the equal sign. To disable it this token has to be in the end of the options string so that no character may be used for "eol", effectively disabling it. If the options string is quoted, it might use quotation mark (") as the "eol", so we must not quote the options string.
• The delims= option, when it's not the last option in the options string, will be terminated by a space. (To include space in "delims" it has to be the last option of FOR /F options.) So delims= followed by a space and then another option disables the "delims".

Solution 5

This worked for me:

SET "SOMETHING=Complex (String) (of stuff!)"
echo !SOMETHING! >> file.txt

View more solutions

Comments

[Greg Hewgill]

Good idea, I would recommend unxutils over cygwin for most situations.

[Richard A]

'The above' here refers to JRL's answer.

[Richard A]

This could be simplifed by using setlocal and endlocal rather than dereferencing the two local variables. I prefer my solution, though.

[Rich]

For a single batch you should probably rather use setlocal enabledelayedexpansion. No need to mess around in the registry or tell users how to call cmd.

[BHARATHWAJ]

Thanks for the 'setlocal' tip, didn't know that one.

[Jens Schauder]

Great! Is there a similar easy way to strip the quotes when providing a parameter? For the case where we have control only over the calling side, but not the script processing the parameter?

[Richard A]

Would it be sufficient to wrap your call in your own routine that did the stripping, as above, before doing the call?

[Jim2B]

Interestingly this does not work for me. set thestring=%~1 yields "The syntax of the command is incorrect.", even when I use identical syntax to that shown by Richard and also despite seeing the same text in the "call /?" section.

[Jim2B]

The problem is in my text. It is xml and has "<" & ">" in it. So Richard's solution does work, I just need to figure out another means of manipulating that text.

[Richard A]

That's a tricky one, @Jim2B, you might be able to escape the < and > with ^ before it gets into batch land. It depends upon your context.

[Jim2B]

Richard, what I eventually did was store the text I needed in a separate file and then performed "type file.txt >> output.txt". It seems like this successfully passes the ">" & "<" without any attempt at interpretation. Even when I tried using the "^<" syntax, it still didn't like something in the string and I didn't have the time to work out the exact issue.

[Richard A]

@Jim2B sometimes life is just too short. I'm glad you solved it, one way or another.

[HardcoreHenry]

Hi, and welcome to SO -- This would fit better in a comment than in an answer (though being a new contributor, you likely don't have permissions to write comments). Regardless, please see stackoverflow.com/help/how-to-answer for guidelines for answers.

[PeterCo]

I don't think that this works for a STR like "This & That"

[Tzunghsing David Wong]

After adding SETLOCAL ENABLEDELAYEDEXPANSION first, this solution works for me (on Windows 10 cmd.exe)

[Mike Q]

I should have mentioned that was required because of the !VARIABLE! instead of %VARIABLE%

[Michael Burr]

NIce trick. But terrible that MS's irresponsible, ad hoc approach to the cmd.exe batch language makes these kinds of hacks necessary.