Create unique file name Windows batch

Question

I have seen many posts about creating a unique filename from the naive %TIME% to the plausible (but insufficient) %RANDOM%. Using wmic os get localdatetime is m

Answer 1

I like Aacini's JScript hybrid solution. As long as we're borrowing from other runtime environments, how about using .NET's System.GUID with PowerShell?

@echo off
setlocal

for /f "delims=" %%I in ('powershell -command "[string][guid]::NewGuid()"') do (
    set "unique_id=%%I"
)

echo %unique_id%

Answer 2

you can try with guid.bat

for /f "tokens=* delims={}" %%# in ('guid.bat') do set "unique=%%#"
echo %unique%

for usage directly from console:

for /f "tokens=* delims={}" %# in ('guid.bat') do @set "unique=%#"

Answer 3

I would like to submit another method and find out if there are any holes is it. Please let me know. Thanks.

C:>title my shell a80en333xyb

C:>type getppid.ps1
(Get-WmiObject -Class Win32_Process -Filter "processid='$pid'").ParentProcessId

C:>powershell getppid.ps1
2380

Or, to run it without creating a .ps1 file:

powershell -NoProfile -Command "(Get-WmiObject -Class Win32_Process -Filter "processid=`'$pid`'").ParentProcessId"

To verify that the correct task is found, the title is set to an unlikely value and tasklist.exe is used to search for the value returned by getppid.ps1.

C:>tasklist /v | find "2380"
cmd.exe                       2380 RDP-Tcp#0                  7      8,124 K Running         PHSNT\pwatson                                           0:00:03 my shell a80en333xyb

Answer 4

The Batch-JScript hybrid script below uses WSH's fso.GetTempName() method that was designed precisely for this purpose:

@if (@CodeSection == @Batch) @then

@echo off

for /F "delims=" %%a in ('cscript //nologo //E:JScript "%~F0"') do set "fileName=%%a"
echo Created file: "%fileName%"
goto :EOF

@end

var fso = new ActiveXObject("Scripting.FileSystemObject"), fileName;
do { fileName = fso.GetTempName(); } while ( fso.FileExists(fileName) );
fso.CreateTextFile(fileName).Close();
WScript.Echo(fileName);

Answer 5

You could use certutil to base64 encode %date% %time% with a %random% seed like this:

@echo off
setlocal

:: generate unique ID string
>"%temp%\~%~n0.%username%.a" echo %username%%date%%time%%random%
>NUL certutil -encode "%temp%\~%~n0.%username%.a" "%temp%\~%~n0.%username%.b"
for /f "usebackq EOL=- delims==" %%I in ("%temp%\~%~n0.%username%.b") do set "unique_id=%%I"
del "%temp%\~%~n0.%username%.a" "%temp%\~%~n0.%username%.b"

echo %unique_id%

In case the same script is being run from the same directory by multiple users, I added %username% to the temp files to avoid further conflict. I suppose you could replace %random% with %username% for the same effect. Then you'd only get a conflict if a single user executes the same code block twice concurrently.

(Edit: added %username% as a seed for uniqueness.)

Answer 6

make the file contents an object, use the pointer memaddress as the first part of your file name and a Rand() as your second part. the memory address will be unique for all objects even with multiple instances running.