only one instance of batch

[Blisk]

I have this script which prevents to run two instances of the same batch.
But problem is because I like to set path for that lock file and whatever I do doesn't work?
 What I amd doing wrong?
original code

Code: [Select]

:init
set "started="
2>nul (
 9>"%~f0.lock" (
  set "started=1"
  call :start
 )
)
@if defined started (
    del "%~f0.lock" >nul 2>nul
) else (
    echo Process aborted: "%~f0" is already running
    @ping localhost > nul
)

exit /b




:start
cd /d %~dp0
start /b notepad.exe
my changed code

Code: [Select]

:init
set "started="
SET PATH=%lockpath%;"d:\test"
2>nul (
 9>"%lockpath%%~f0.lock" (
  set "started=1"
  call :start
 )
)
@if defined started (
    del "%lockpath%%~f0.lock" >nul 2>nul
) else (
    echo Process aborted: "%lockpath%%~f0" is already running
    @ping localhost > nul
)

exit /b

:start
cd /d %~dp0


start /b notepad.exe


[Salmon Trout]

What does variable %lockpath% contain?

if you have killed the system PATH variable by doing this

Code: [Select]

SET PATH=%lockpath%;"d:\test", why do you expect ping to work?

Do you know why it is a bad idea to name your own private variable "PATH"?

Did you write this script yourself or copy it from somewhere?

[Blisk]

I have copied that script, point of that script is to alow only one instance of batch to be run.
with this I tried to make script to create lockfile in folder d:\test

Code: [Select]

SET PATH=%lockpath%;"d:\test"because now script create lockfile in folder where is runned from.

[Blisk]

Any idea about path?

[Salmon Trout]

Run this batch and consider what it tells you

@echo off
Echo (1) running Ping command
echo ------------------------
ping -n 1 127.0.0.1
echo.
set PATH=blablabla
Echo (2) running Ping command
echo ------------------------
ping -n 1 127.0.0.1
pause
 

[Blisk]

(1) running Ping command
------------------------

Pinging 127.0.0.1 with 32 bytes of data:
Reply from 127.0.0.1: bytes=32 time<1ms TTL=128

Ping statistics for 127.0.0.1:
    Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
    Minimum = 0ms, Maximum = 0ms, Average = 0ms

(2) running Ping command
------------------------
'ping' is not recognized as an internal or external command,
operable program or batch file.
Press any key to continue . . .

[Salmon Trout]

What does that tell you?

[Blisk]

What does that tell you?

Sorry, really have no clue

[Salmon Trout]

Did the ping command work both times?

[Salmon Trout]

I told you way up above you shouldn't use a variable called PATH  or path in your scripts. Maybe you didn't read that. You didn't ask why. You don't understand anything about batch scripts, which makes it risky to run scripts you found on the web, and doubly risky to alter them when you don't know what you are doing. You could try something like this below, but maybe you would be better off actually trying to learn how to write your own scripts? or another language? People say good things about Python.

@echo off
setlocal enabledelayedexpansion
echo my name is %~nx0
echo now I look for my name using Tasklist
set found=0
for /f "delims=" %%A in ('tasklist /v ^| find "cmd.exe" ^| find "%~nx0"') do set /a found+=1
echo Found this batch in Tasklist %found% time(s).
if %found% gtr 1 (
   echo Script with same name already running
   echo Exiting...
   pause
   exit
   )
REM rest of script
echo If I reached here I am the only %~nx0 running
pause

[Blisk]

yes you are right.
I have intention to take class for powershell and learn that.
I know using path which is command is not good like using the name of the batch as some exe program in script.
I learn something but still need alot of it to learn.
thank you

when I test this notepad opens everytime when I run it but it should not.

Code: [Select]

@echo off
setlocal enabledelayedexpansion
echo my name is %~nx0
echo now I look for my name using Tasklist
set found=0
for /f "delims=" %%A in ('tasklist /v ^| find "cmd.exe" ^| find "%~nx0"') do set /a found+=1
echo Found this batch in Tasklist %found% time(s).
if %found% gtr 1 (
   echo Script with same name already running
   echo Exiting...
   pause
   exit
   )
notepad.exe
echo If I reached here I am the only %~nx0 running
pause

[Salmon Trout]

I thought you wanted a batch which would only allow one running instance of itself.

[Blisk]

I thought you wanted a batch which would only allow one running instance of itself.

Yes it should run only one instance of batch but I see sometimes is runned two or more.
That's why I was searching for a script which will prevent starting another when first one already runs.
So script which I post it do that, but problem is I can't set a path where it save that lock files.

[Salmon Trout]

When I run that script, while it is still running, if you open a new command window, and run it again, the new instance exits without starting Notepad.

[Blisk]

When I run that script, while it is still running, if you open a new command window, and run it again, the new instance exits without starting Notepad.

When I do that it opens notepad everytime.
I tested 3 times and opened 3 notepads.

[Salmon Trout]

Do you have tasklist.exe on your system?

[Blisk]

I have it. As far as I know all windows 7,8,10 have it.

[Blisk]

Any more ideas for this? 

[Geek-9pm]

Yes, you asked for one instance of batch and that is what  yu got.
Did you want something else?
If so, what?
You are starting another Notepad.exe.
The batch file does not control that.
You did not make the batch file owner for notepad.You transferred control to notepad and the batch finished, the batch file is closed after notepad opens.
Keep the batch open while notepad is running.

[Blisk]

Yes, you asked for one instance of batch and that is what  yu got.
Did you want something else?
If so, what?
You are starting another Notepad.exe.
The batch file does not control that.
You did not make the batch file owner for notepad.You transferred control to notepad and the batch finished, the batch file is closed after notepad opens.
Keep the batch open while notepad is running.

but it is not one instance of batch, when I run it second time it opens second notepad.
I just like to have a script which do the same as script I posted. I only want to choose in which folder lock file is.

[Geek-9pm]

but it is not one instance of batch, when I run it second time it opens second notepad.
I just like to have a script which do the same as script I posted. I only want to choose in which folder lock file is.

You are wrong.
The batch given by Salmon Trout  is one instance.
Pay attention to the detail.The batch must be the owner of the NOTEPAD invocation.
Your script gives control to Notepad.exe and becomes not an instance.
You must use the CALL testament.
Like this:

Code: [Select]

call notepad.exe
That works. 

[Blisk]

no it doesn't work
everytime I start batch it opens another notepad.exe and I used
call notepad.exe

[Geek-9pm]

On my system the batch file is one one instance. I can not even start another instance of it.
When your said  "only one instance of batch", what did you mean?
Will the batch file take control of another computer in another country? No.
Will the batch file become Lord and Master of the Windows Operating System? No.
Any batch file has a limited scope of control.
All the batch can do is prevent another instance of itself inside of its own dominion. The batch file itself is a child of CMD.EXE.

When I test this in Windows 7, I can not even get a commend prompt until Note Pad has closed.

I agree with Salmon Trout. You do not understand what  your are doing. You should learn a modern scripting language suitable to your needs. Python is a very good choice and currently there are many places where you can find tutorials.

I think you should read this:

Python – a Multiplatform Alternative to Bash/Batch Scripts?

The article is very good in making a point. Batch is not good for development of a powerful program that uses all of the features of your computer.

Instead of Python, you could learn to use Ruby. Or even VBA script.  Even javascript.
Batch is good for some scenarios. But it is a bad learning tool, unless you enjoy pain. 

EDIT: This is not just what I say. Look here:
The Five Best Programming Languages Worth Learning.

No matter whether you’re hoping to develop websites, software, games or a bit of everything, expanding your knowledge of different programming languages is essential in today’s ever-changing industry climate.

[Blisk]

thank you for your advice and ponting suggestion what I should start learn. I will do that, first I will go to take some powershell lessons.

About this script as I said before when I start batch file it opens notepad, when I double click again on batch file it opens another notepad and if I dobule click third time on batch file I get third notepad open.

Whole idea is to prevent starting batch file until first instance runs, but this script doesn't and one I posted it does but problem is lockfile path.

I will give you my computer to test it but I can't.
I have wind 10 professional and also tested on win 7 enterprise and on both is the same, no matter how many times I double click on batch file, everytime it opens notepad, so I can open as many as I want and that means script doesn't work.

[Salmon Trout]

@echo off
set lockfile=%~dpnx0.lock
echo Lockfile is %lockfile%
if exist "%lockfile%" (
   echo already running
   exit /b
) else (
   echo Lockfile not found
   echo Writing lockfile
   echo !date! !time! > "%lockfile%"
)
echo.
echo Rest of the batch file
echo.
echo Ready to delete lockfile
echo and exit batch file
pause
del "%lockfile%" && echo Lockfile deleted

[Salmon Trout]

Note: the lockfile can be anywhere you like, and named anything you want:

set lockfile=d:\locks\batchlock.xyz

Also note:

The echo statements in the batch, and the final pause command, are there so you can see how it works, and can be removed if you want.

[Blisk]

Thank you this works I changed
set lockfile=d:\locks\batchlock.lock

I also tried if lockfile can be generated from file name with this
set lockfile=d:\locks\%~dpnx0.lock
but that didn't work
%~dpnx0 is for full path variable

I will use first option.
thank you again.

[Salmon Trout]

I also tried if lockfile can be generated from file name with this
set lockfile=d:\locks\%~dpnx0.lock
but that didn't work
%~dpnx0 is for full path variable

Let's break down what %~dpnx0 means

%0 is is the batch file name and path, also, so is %~dpnx0

%~ and....
d is the drive letter (and colon) (
p is the path
n is the name
x is the extension

You can combine them

If your file is C:\Files\Sub\MyFile.bat

%~d0 expands to C:
%~p0 expands to \Files\Sub\
%~n0 expands to MyFile
%~x0 expands to .bat

So to make MyFile.lock you need %~n0.lock and you can put it in folder D:\whatever\somewhere\ with D:\whatever\somewhere\%~n0.lock

Reminder: don't make a batch variable called PATH, in upper or lower case, unless you really want to, and you know what you are doing. It will kill lots of batch functions.

[Blisk]

thank you.
you are a great man I learned alot from you.