Windows Batch`for`循环中不带换行符的Echo

Question

Please note: This question is not about how to echo without a newline. It's about to pipe a variable without a newline and store the result in another variable. Please don't mark this question as duplicate to other questions answering only how to remove newlines!

I have a variable a which I want to pass to a program (let's use more for the sake of this example), and its result should be stored into another variable b . This is to prevent the creation of temporary files. Sticking some answers from other questions here together, this could be achieved by something like this:

FOR /f "tokens=*" %%t IN ('ECHO %a% ^| MORE') DO SET b=%%t

Which works -- BUT will add another newline on my variable! So I tried the following tricks you find on stackoverflow/superuser to prevent the newline. If you do these without the loop, they work perfectly! But once you put them in a loop, they fail:

FOR /f "tokens=*" %%t IN ('ECHO ^| SET /p="%a%" ^| MORE') DO SET b=%%t
FOR /f "tokens=*" %%t IN ('^<NUL SET /p="%a%" ^| MORE') DO SET b=%%t

It will always say The syntax of the command is incorrect. What am I missing? Please help me!

Answer 1

If you run your command

FOR /f "delims=" %%t IN ('^<NUL SET /p="%a%" ^| more ') DO SET "b=%%t"

with echo ON you will see the equal sign in the set command has vanished, it has been removed by the parser leaving an incorrect command.

You have two options:

FOR /f "delims=" %%t IN ('^<NUL SET /p^="%a%" ^| more ') DO SET "b=%%t"
FOR /f "delims=" %%t IN ('^<NUL SET /p"=%a%" ^| more ') DO SET "b=%%t"

The first one escapes the equal sign. The second one quotes it.