Redirecting Output from within Batch file

I am creating a batch file with some simple commands to gather information from a system. The batch file contains commands to get the time, IP information, users, etc.

I assembled all the commands in a batch file, and it runs, but I would like the batch file, when run to output the results to a text file (log). Is there a command that I can add to the batch that would do so?

Keep in mind I do not want to run the batch from cmd, then redirect output ; I want to redirect the output from inside the batch, if that is possible.

The simple naive way that is slow because it opens and positions the file pointer to End-Of-File multiple times.

@echo off
command1 >output.txt
command2 >>output.txt
...
commandN >>output.txt

A better way - easier to write, and faster because the file is opened and positioned only once.

@echo off
>output.txt (
  command1
  command2
  ...
  commandN
)

Another good and fast way that only opens and positions the file once

@echo off
call :sub >output.txt
exit /b

:sub
command1
command2
...
commandN

Edit 2020-04-17

Every now and then you may want to repeatedly write to two or more files. You might also want different messages on the screen. It is still possible to to do this efficiently by redirecting to undefined handles outside a parenthesized block or subroutine, and then use the & notation to reference the already opened files.

call :sub 9>File1.txt 8>File2.txt
exit /b

:sub
echo Screen message 1
>&9 echo File 1 message 1
>&8 echo File 2 message 1
echo Screen message 2
>&9 echo File 1 message 2
>&8 echo File 2 message 2
exit /b

I chose to use handles 9 and 8 in reverse order because that way is more likely to avoid potential permanent redirection due to a Microsoft redirection implementation design flaw when performing multiple redirections on the same command. It is highly unlikely, but even that approach could expose the bug if you try hard enough. If you stage the redirection than you are guaranteed to avoid the problem.

3>File1.txt ( 4>File2.txt call :sub)
exit /b

:sub
etc.

if you want both out and err streams redirected

dir >> a.txt 2>&1

I know this is an older post, but someone will stumble across it in a Google search and it also looks like some questions the OP asked in comments weren't specifically addressed. Also, please go easy on me since this is my first answer posted on SO. :)

To redirect the output to a file using a dynamically generated file name, my go-to (read: quick & dirty) approach is the second solution offered by @dbenham. So for example, this:

@echo off
> filename_prefix-%DATE:~-4%-%DATE:~4,2%-%DATE:~7,2%_%time:~0,2%%time:~3,2%%time:~6,2%.log (
echo Your Name Here
echo Beginning Date/Time: %DATE:~-4%-%DATE:~4,2%-%DATE:~7,2%_%time:~0,2%%time:~3,2%%time:~6,2%.log
REM do some stuff here
echo Your Name Here
echo Ending Date/Time: %DATE:~-4%-%DATE:~4,2%-%DATE:~7,2%_%time:~0,2%%time:~3,2%%time:~6,2%.log
)

Will create a file like what you see in this [screenshot of the file in the target directory][1]

That will contain this output:

Your Name Here
Beginning Date/Time: 2016-09-16_141048.log
Your Name Here
Ending Date/Time: 2016-09-16_141048.log

Also keep in mind that this solution is locale-dependent, so be careful how/when you use it. [1]: http://i.stack.imgur.com/3v9Df.png

echo some output >"your logfile"

or

(
 echo some output
 echo more output
)>"Your logfile"

should fill the bill.

If you want to APPEND the output, use >> instead of >. > will start a new logfile.

@echo off
>output.txt (
echo Checking your system infor, Please wating...

systeminfo | findstr /c:"Host Name" 
systeminfo | findstr /c:"Domain"

ipconfig /all | find "Physical Address" 

ipconfig | find "IPv4" 
ipconfig | find "Default Gateway"

)

@pause

There is a cool little program you can use to redirect the output to a file and the console

some_command  ^|  TEE.BAT  [ -a ]  filename 

@ECHO OFF
:: Check Windows version
IF NOT "%OS%"=="Windows_NT" GOTO Syntax

:: Keep variables local
SETLOCAL

:: Check command line arguments
SET Append=0
IF /I [%1]==[-a] (
	SET Append=1
	SHIFT
)
IF     [%1]==[] GOTO Syntax
IF NOT [%2]==[] GOTO Syntax

:: Test for invalid wildcards
SET Counter=0
FOR /F %%A IN ('DIR /A /B %1 2^>NUL') DO CALL :Count "%%~fA"
IF %Counter% GTR 1 (
	SET Counter=
	GOTO Syntax
)

:: A valid filename seems to have been specified
SET File=%1

:: Check if a directory with the specified name exists
DIR /AD %File% >NUL 2>NUL
IF NOT ERRORLEVEL 1 (
	SET File=
	GOTO Syntax
)

:: Specify /Y switch for Windows 2000 / XP COPY command
SET Y=
VER | FIND "Windows NT" > NUL
IF ERRORLEVEL 1 SET Y=/Y

:: Flush existing file or create new one if -a wasn't specified
IF %Append%==0 (COPY %Y% NUL %File% > NUL 2>&1)

:: Actual TEE
FOR /F "tokens=1* delims=]" %%A IN ('FIND /N /V ""') DO (
	>  CON    ECHO.%%B
	>> %File% ECHO.%%B
)

:: Done
ENDLOCAL
GOTO:EOF

:Count
SET /A Counter += 1
SET File=%1
GOTO:EOF

:Syntax
ECHO.
ECHO Tee.bat,  Version 2.11a for Windows NT 4 / 2000 / XP
ECHO Display text on screen and redirect it to a file simultaneously
ECHO.
IF NOT "%OS%"=="Windows_NT" ECHO Usage:  some_command  ³  TEE.BAT  [ -a ]  filename
IF NOT "%OS%"=="Windows_NT" GOTO Skip
ECHO Usage:  some_command  ^|  TEE.BAT  [ -a ]  filename
:Skip
ECHO.
ECHO Where:  "some_command" is the command whose output should be redirected
ECHO         "filename"     is the file the output should be redirected to
ECHO         -a             appends the output of the command to the file,
ECHO                        rather than overwriting the file
ECHO.
ECHO Written by Rob van der Woude
ECHO http://www.robvanderwoude.com
ECHO Modified by Kees Couprie
ECHO http://kees.couprie.org
ECHO and Andrew Cameron

Add these two lines near the top of your batch file, all stdout and stderr after will be redirected to log.txt:

if not "%1"=="STDOUT_TO_FILE"  %0 STDOUT_TO_FILE %*  >log.txt 2>&1
shift /1

@echo OFF
[your command] >> [Your log file name].txt

I used the command above in my batch file and it works. In the log file, it shows the results of my command.

Adding the following lines at the bottom of your batch file will grab everything just as displayed inside the CMD window and export into a text file:

powershell -c "$wshell = New-Object -ComObject wscript.shell; $wshell.SendKeys('^a')
powershell -c "$wshell = New-Object -ComObject wscript.shell; $wshell.SendKeys('^c')
powershell Get-Clipboard > MyLog.txt

It basically performs a select all -> copy into clipboard -> paste into text file.

This may fail in the case of "toxic" characters in the input. Considering an input like thisIsAnIn^^^^put is a good way how to get understand what is going on. Sure there is a rule that an input string MUST be inside double quoted marks but I have a feeling that this rule is a valid rule only if the meaning of the input is a location on a NTFS partition (maybe it is a rule for URLs I am not sure). But it is not a rule for an arbitrary input string of course (it is "a good practice" but you cannot count with it).