is there any tool that allows redirecting output to env variable in windows *.cmd script?

Question

I mean to use it like this:

echo some data | this-tool-m-searching-for -vn myvariable

or

time | this-tool-m-searching-for -vn current_time

etc..

and then

echo %myvariable%

would produce some data etc...

This is not about echo or time only, I mean any program that gives output to stdout.

Answer 1

This is the usual construction, I believe:

for /F %i in ('time /t') do set current_time=%i

(as usual, the percent signs need to be doubled in a command script.)

Another construction, though awkward:

time /t > tempfile.txt
set /p current_time= < tempfile.txt

There appears to be no way to avoid the temporary file; if you use a pipe, the set command happens in a subprocess. (In some situations you might be able to pipe the output to a second copy of your batch script, but that sort of thing can get ugly fast.)

Additional

To expand on my last point, in response to a question in the comments, here is an example batch file which pipes output into a new instance of itself:

if "%1" NEQ "" @goto %1
:step1
time /t | %0 step2
goto :eof
:step2
set /p current_time=
echo %current_time%
rem processing here...

I don't think this solution scales well for more complicated batch scripts.

Answer 2

Try export.exe, it seems to do exactly what you're after.