How to use the same output file from two commands which are piped in batch

Question

Assuming I have the following batch comannd which works as expected.

file1.exe | file2.exe

Now I have the following requirement. - Stderr from file1.exe should be written to a logfile - Stdout and Stderr from file2.exe should be written to a logfile

This works, too

file1.exe 2>>file1.log | file2.exe >>file2.log 2>&1

However, what I really want is to have both outputs in the same file. This fails because file.log is used by another process

file1.exe 2>>file.log | file2.exe >>file.log 2>&1

Here is a real world example to demonstrate the issue.

echo test 2>>file.log | findstr t 1>>file.log 2>&1

Answer 1

If you don't need to execute this task in properly real time, you can also create two different temporary files:

file1.exe 2 >> temp1.log | file2.exe >> temp2.log

And then you can print the second text file to the first one:

echo. >> temp1.log && type temp2.log >> temp1.log
REM "echo." leaves a blank line in the output file

Answer 2

Try this:

( echo test | findstr t ) >>file.log 2>&1

Answer 3

This will pipe all the data to findstr:

echo test 2>&1 | findstr "^" >file.log 2>&1