fastboot getvar from batch file

I was trying to get certain fastboot variables from a batch file. I was using something like :

for /f "tokens=2 delims=:" %%a in ('fastboot.exe getvar version-bootloader') do @echo version is %%a

But I get the output on command line, not in the variable %%a. the command 'fastboot.exe getvar version-bootloader' works perfectly in command-line. I also tried doing:

fastboot.exe getvar version-bootloader >> temp.txt

but temp.txt is always empty and i receive the output on the command line, instead of the file. Is there an alternative to this?

fastboot output is directed to error stream, you can direct error stream to standard stream by adding 2>&1

1. your script will get two lines since fastboot getvar returns additional line with time elapsed.
2. your script parses the version with a leading space, you shoud add a space to the delimiter (it is default but when you give delims it is overwritten)

you should use:

for /f "tokens=2 delims=: " %%a in ('fastboot.exe getvar version-bootloader 2^>^&1 ^| findstr version') do @echo version is %%a