When I'm writing batch programs I tend to create a goto loop to set and display things.
Example:
#echo off & setlocal enabledelayedexpansion
:loop
if !num! GTR !max!
set /a "num=num+1"
echo display!num! = !display%num%!
goto :loop
I had a feeling that I can replace this with a for loop, but I had no success creating one that can replace the loop above. Does anyone know?
You can use a for /L loop.
for /L %%A in (!num!,1,!max!) do echo display%%A = !display%%A!
Where !num! is your starting number, !max! is your ending number, and 1 means count up by ones.
#echo off
setlocal enableextensions enabledelayedexpansion
rem Set limits
set /a "num=1", "max=10"
rem Prepare a set of variables to test
for /l %%a in (%num% 1 %max%) do set "display%%a=!random!"
rem Show the variables contents
for /l %%a in (%num% 1 %max%) do echo display%%a=!display%%a!
Related
I made this code
dir /B /S %RepToRead% > %FileName%
for /F "tokens=*" %%a in ('type %FileName%') do (
set z=%%a
echo %z%
echo %%a
)
echo %%a is working fine but echo %z% returns "echo disabled".
I need to set a %z% because I want to split the variable like %z:~7%
Any ideas?
There are two methods to setting and using variables within for loops and parentheses scope.
setlocal enabledelayedexpansion see setlocal /? for help. This only works on XP/2000 or newer versions of Windows.
then use !variable! instead of %variable% inside the loop...
Create a batch function using batch goto labels :Label.
Example:
for /F "tokens=*" %%a in ('type %FileName%') do call :Foo %%a
goto End
:Foo
set z=%1
echo %z%
echo %1
goto :eof
:End
Batch functions are very useful mechanism.
You probably want SETLOCAL ENABLEDELAYEDEXPANSION. See https://devblogs.microsoft.com/oldnewthing/20060823-00/?p=29993 for details.
Basically: Normal %variables% are expanded right aftercmd.exe reads the command. In your case the "command" is the whole
for /F "tokens=*" %%a in ('type %FileName%') do (
set z=%%a
echo %z%
echo %%a
)
loop. At that point z has no value yet, so echo %z% turns into echo. Then the loop is executed and z is set, but its value isn't used anymore.
SETLOCAL ENABLEDELAYEDEXPANSION enables an additional syntax, !variable!. This also expands variables but it only does so right before each (sub-)command is executed.
SETLOCAL ENABLEDELAYEDEXPANSION
for /F "tokens=*" %%a in ('type %FileName%') do (
set z=%%a
echo !z!
echo %%a
)
This gives you the current value of z each time the echo runs.
I struggeld for many hours on this.
This is my loop to register command line vars.
Example : Register.bat /param1:value1 /param2:value2
What is does, is loop all the commandline params,
and that set the variable with the proper name to the value.
After that, you can just use
set value=!param1!
set value2=!param2!
regardless the sequence the params are given. (so called named parameters).
Note the !<>!, instead of the %<>%.
SETLOCAL ENABLEDELAYEDEXPANSION
FOR %%P IN (%*) DO (
call :processParam %%P
)
goto:End
:processParam [%1 - param]
#echo "processparam : %1"
FOR /F "tokens=1,2 delims=:" %%G IN ("%1") DO (
#echo a,b %%G %%H
set nameWithSlash=%%G
set name=!nameWithSlash:~1!
#echo n=!name!
set value=%%H
set !name!=!value!
)
goto :eof
:End
Simple example of batch code using %var%, !var!, and %%.
In this example code, focus here is that we want to capture a start time using the built in variable TIME (using time because it always changes automatically):
Code:
#echo off
setlocal enabledelayedexpansion
SET "SERVICES_LIST=MMS ARSM MMS2"
SET START=%TIME%
SET "LAST_SERVICE="
for %%A in (%SERVICES_LIST%) do (
SET START=!TIME!
CALL :SOME_FUNCTION %%A
SET "LAST_SERVICE=%%A"
ping -n 5 127.0.0.1 > NUL
SET OTHER=!START!
if !OTHER! EQU !START! (
echo !OTHER! is equal to !START! as expected
) ELSE (
echo NOTHING
)
)
ECHO Last service run was %LAST_SERVICE%
:: Function declared like this
:SOME_FUNCTION
echo Running: %1
EXIT /B 0
Comments on code:
Use enabledelayedexpansion
The first three SET lines are typical
uses of the SET command, use this most of the time.
The next line is a for loop, must use %%A for iteration, then %%B if a loop inside it
etc.. You can not use long variable names.
To access a changed variable such as the time variable, you must use !! or set with !! (have enableddelayexpansion enabled).
When looping in for loop each iteration is accessed as the %%A variable.
The code in the for loop is point out the various ways to set a variable. Looking at 'SET OTHER=!START!', if you were to change to SET OTHER=%START% you will see why !! is needed. (hint: you will see NOTHING) output.
In short !! is more likely needed inside of loops, %var% in general, %% always a for loop.
Further reading
Use the following links to determine why in more detail:
Difference between %variable% and !variable! in batch file
Variable usage in batch file
To expand on the answer I came here to get a better understanding so I wrote this that can explain it and helped me too.
It has the setlocal DisableDelayedExpansion in there so you can locally set this as you wish between the setlocal EnableDelayedExpansion and it.
#echo off
title %~nx0
for /f "tokens=*" %%A in ("Some Thing") do (
setlocal EnableDelayedExpansion
set z=%%A
echo !z! Echoing the assigned variable in setlocal scope.
echo %%A Echoing the variable in local scope.
setlocal DisableDelayedExpansion
echo !z! &rem !z! Neither of these now work, which makes sense.
echo %z% &rem ECHO is off. Neither of these now work, which makes sense.
echo %%A Echoing the variable in its local scope, will always work.
)
set list = a1-2019 a3-2018 a4-2017
setlocal enabledelayedexpansion
set backup=
set bb1=
for /d %%d in (%list%) do (
set td=%%d
set x=!td!
set y=!td!
set y=!y:~-4!
if !y! gtr !bb1! (
set bb1=!y!
set backup=!x!
)
)
rem: backup will be 2019
echo %backup%
Try this:
setlocal EnableDelayedExpansion
...
for /F "tokens=*" %%a in ('type %FileName%') do (
set z=%%a
echo !z!
echo %%a
)
You can use a macro if you access a variable outside the scope
#echo off
::Define macro
set "sset=set"
for /l %%a in (1,1,4) do (
::set in loop
%sset% /a "x[%%a]=%%a*%%a"
if %%a equ 4 (
:: set in condition
%sset% "x[%%a]=x Condition"
%sset% "y=y Condition"
)
)
echo x1=%x[1]% x2=%x[2]% x3=%x[3]% x4=%x[4]% y=%y%
:: Bonus. enableDelayedExpansion used to access massive from the loop
setlocal enableDelayedExpansion
echo Echo from the loop
for /l %%a in (1,1,4) do (
::echo in one line - echo|set /p =
echo|set /p "=x%%a=!x[%%a]! "
if %%a equ 4 echo y=%y%
)
pause
I know this isn't what's asked but I benefited from this method, when trying to set a variable within a "loop". Uses an array. Alternative implementation option.
SETLOCAL ENABLEDELAYEDEXPANSION
...
set Services[0]=SERVICE1
set Services[1]=SERVICE2
set Services[2]=SERVICE3
set "i=0"
:ServicesLoop
if defined Services[%i%] (
set SERVICE=!Services[%i%]!
echo CurrentService: !SERVICE!
set /a "i+=1"
GOTO :ServicesLoop
)
The following should work:
setlocal EnableDelayedExpansion
for /F "tokens=*" %%a in ('type %FileName%') do (
set "z=%%a"
echo %z%
echo %%a
)
I have searched this everywhere and I didn't found it, so what I want to do is simple, I want to count the underscores in a filename and put it in a variable to later use it.
Is there any simple batch code to do it ?
#echo off
setlocal enabledelayedexpansion
set filename=__example_file.bin_
set cnt=0
set pos=0
:loop
if "!filename:~%pos%,1!"=="_" set /a cnt=%cnt%+1
set /a pos=%pos%+1
if not "!filename:~%pos%,1!"=="" goto loop
echo Count: %cnt%
That code is pretty ugly but I can't find a better way so far.
A different method to count underscores (or more exact elements separated by an underscore)
is to use self expanding code:
:: Q:\Test\2017\08\28\SO_45917406.cmd
#echo off & setlocal enabledelayedexpansion
set "FileName=example_file_name_20170828_181000.txt"
Set i=1&Set "FileName[!i!]=%FileName:_="&Set /a i+=1&Set "FileName[!i!]=%"
Echo Counted %i% underscore separated elements
Set FileName
Sample output:
> Q:\Test\2017\08\28\SO_45917406.cmd
Counted 5 underscore separated elements
FileName=example_file_name_20170828_181000.txt
FileName[1]=example
FileName[2]=file
FileName[3]=name
FileName[4]=20170828
FileName[5]=181000.txt
This solution is inspired from #xmcp :
#echo off
Rem The srting to count in the filename is the underscrore "_"
Rem we can of course set another one ;)
set "MyString=_"
setlocal enabledelayedexpansion
#for /f "delims=" %%a in ('Dir /b "%userprofile%\Desktop"') do (
set "filename=%%a"
set /a "cnt=0"
set /a "pos=0"
Call:Counting_String "!filename!" "%Mystring%"
)
pause & exit
::*********************************************************
:Counting_String <filename> <MyString>
set "filename=%~1"
set "string=%~2"
if /I "!filename:~%pos%,1!"=="%Mystring%" set /a cnt+=1
set /a pos+=1
if not "!filename:~%pos%,1!"=="" goto Counting_String
echo !filename!: [!cnt!] "%Mystring%"
exit /b
::*********************************************************
Hi I managed to get the code below to create a list of numbers and place a comma at the end of each number created However, it has proven to be quite the challenge to get them on the same line separated by a ,[space]
#ECHO OFF
setlocal EnableDelayedExpansion
set _Output=%UserProfile%\Desktop\NumGen.txt
::only change these three lines
set "start=1" ::starts from this number
set "amount=10" ::amount of files created
set "length=5" ::length of fileNames
set "join_with=, " ::what to join each number with
set /a "last=%start%+%amount%"
for /l %%i in (%start%,1,%last%) do (
set "folderName=0000000000%%i"
set "folderName=!folderName:~-%length%!%join_with%"
>>"%_Output%" ECHO.!folderName!
)
pause
so my output at the moment is
00001,
00002,
00003,
00004,
00005,
00006,
00007,
00008,
00009,
00010,
00011,
However I would like it to be
00001, 00002, 00003, 00004, 00005, 00006, 00007, 00008, 00009, 00010, 00011
I have windows 10 64bit. Any help will be appreciated
echo is not able to do that. But there is a workaround, (ab)using the set command:
for /l %%i in (1,1,5) do (
<nul set /p "=%%i, "
)
echo(
After a long break I decided to give this another bash and presto. Success :-)
::CallScript
#ECHO OFF
CALL :ScriptA
CALL :ScriptB
CALL :ScriptC
pause
goto :eof
:ScriptA
#ECHO OFF
setlocal EnableDelayedExpansion
set _Output=%UserProfile%\Desktop\NumGen.txt
::only change these three lines
set "start=1"
set "amount=10"
set "length=5"
set "join_with=, "
set /a "last=%start%+%amount%"
for /l %%i in (%start%,1,%last%) do (
set "folderName=0000000000%%i"
set "folderName=!folderName:~-%length%!%join_with%"
>>"%_Output%" ECHO.!folderName!
)
goto :eof
:ScriptB
#ECHO OFF
setlocal enableextensions enabledelayedexpansion
set "var="
for /f "usebackq delims=" %%a in ("%UserProfile%\Desktop\NumGen.txt") do set "var=!var!%%a"
echo %var%> "%UserProfile%\Desktop\NumList.txt"
goto :eof
:ScriptC
#ECHO OFF
del "%UserProfile%\Desktop\NumGen.txt"
goto :eof
This code determines the starting number, the amount of numbers, the length of the numbers and joins them with , "
Then ScriptB concatenates each number together with the , " and saves to NumList.txt
Lastly the script deletes the NumGen.txt file.
Stephan has one solution with SET /P. The other option is to build the entire string within an environment variable, and then write after the loop ends. This is significantly faster, but it will fail if the final string length exceeds ~8191 bytes.
set "str="
for /l %%i in (%start%,1,%last%) do (
set "folderName=0000000000%%i"
set "str=!str!!folderName:~-%length%!%join_with%"
)
>>"%_Output%" ECHO.!str!
You could remove the unwanted trailing , if you want:
>>"%_Output%" ECHO.!str:~0,-2!
I want to use a variable skip parameter in for loop, but it won't let me do it.
Here is my code
#echo off
setlocal ENABLEDELAYEDEXPANSION
set /p testcase=<testcases.txt
set /a end=%testcase%*13
for /L %%P IN (1,13,%end%) DO (
set skip=skip=%%P
echo !skip!
set vidx=0
for /f "%skip%" %%A in (testcases.txt) do (
set /a vidx=!vidx! + 1
set var!vidx!=%%A
)
)
Here skip is skip=1, but it doesn't skip any line. When I replace it with skip=1. then it works fine, but I want to skip variable no. of lines in each iteration. Please help.
I think with this logic the only option is a subroutine:
#echo off
setlocal ENABLEDELAYEDEXPANSION
set /p testcase=<testcases.txt
set /a end=%testcase%*13
for /L %%P IN (1,13,%end%) DO (
set skip=skip=%%P
echo !skip!
set vidx=0
call :innerFor %%P
)
exit /b 0
:innerFor
for /f "skip=%~1" %%A in (testcases.txt) do (
set /a vidx=!vidx! + 1
set var!vidx!=%%A
)
exit /b 0
parametrization of FOR /F options is a little bit tricky..
Though I have no the content of your files I cant test if this works correctly .
in Windows Batch, if I had a variable (length can change) that was, for example: "hello world!"
is it possible to "split" the variable so each character is its own variable so the output could look like:
t1=h
t2=e
t3=l
etc.
Any help would be appreciated.
Use this code:
setlocal EnableDelayedExpansion
set str="hello world^!"
set tempstr=%str%
set count=0
:loop
if defined tempstr (
set tempstr=%tempstr:~1%
set /a count+=1
set /a pos=%count%-1
set t!count!=!str:~%pos%,1!
goto loop
)
:: check the generated variables
set t
To get the nth character in a string, use set char=%str:~n,1%.
I hope this was helpful!
Here is a variant using for /L to iterate over all characters of the string. The number of characters, so the length of the string, is retrieved in sub-routine :LENGTH first:
#echo off
setlocal EnableExtensions DisableDelayedExpansion
rem // Define constants here:
set "_STRING=Hello world!"
call :LENGTH LEN "%_STRING%"
setlocal EnableDelayedExpansion
for /L %%I in (0,1,%LEN%) do (
set "$CHR[%%I]=!_STRING:~%%I,1!"
)
set $CHR
endlocal
endlocal
exit /B
:LENGTH rtn_length val_string
setlocal DisableDelayedExpansion
set /A "RET=0" & set "STR=%~2"
if defined STR set /A "RET=1"
setlocal EnableDelayedExpansion
for %%L in (4096 2048 1024 512 256 128 64 32 16 8 4 2 1) do (
if not "!STR:~%%L,1!"=="" (
set /A "RET+=%%L"
set "STR=!STR:~%%L!"
)
)
(
endlocal
endlocal
set "%~1=%RET%"
)
exit /B
Here is a different variant, using cmd /U to convert the string into Unicode, where a null-byte becomers inserted behind every character, and find, which treats these null-bytes like end-of-line markers:
#echo off
setlocal EnableExtensions DisableDelayedExpansion
rem // Define constants here:
set "_STRING=Hello world!"
set /A "IDX=0"
for /F delims^=^ eol^= %%I in ('
cmd /U /V /C echo^(!_STRING!^| find /V ""
') do (
set "CHR=%%I"
setlocal EnableDelayedExpansion
for /F "delims=" %%J in ("$CHR[!IDX!]=!CHR!") do (
endlocal
set "%%J"
)
set /A "IDX+=1"
)
set $CHR
endlocal
exit /B
Finally, here is another variant, based on a goto loop. This uses a position pointer POS to scan the string and to extract a single character. If no character is returned, the end of the string is reached:
#echo off
setlocal EnableExtensions DisableDelayedExpansion
rem // Define constants here:
set "_STRING=Hello world!"
setlocal EnableDelayedExpansion
if not defined _STRING goto :QUIT
set /A "POS=0"
:LOOP
set "CHR=!_STRING:~%POS%,1!"
if defined CHR (
set "$CHR[%POS%]=!CHR!"
set /A "POS+=1"
goto :LOOP
)
:QUIT
set $CHR
endlocal
endlocal
exit /B
Old thread, but accepted answer misses letter d?
Changed
set /a pos=%count%-1 to
set /a pos=!count!-1
setlocal EnableDelayedExpansion
set str="hello world!"
set tempstr=%str%
set count=0
:loop
if defined tempstr (
set tempstr=%tempstr:~1%
set /a count+=1
set /a pos=!count!-1
set t!count!=!str:~%pos%,1!
goto loop
)
:: check the generated variables
set t
pause
Here is another version.
variables start with 0, though
setlocal EnableDelayedExpansion
set var="hello world!"
rem remove quotes
set var=%var:"=%
rem add limiter
set var=%var%_
echo %var%
set count=0
:loop
set tempvar=!var:~%count%,1!
if !tempvar!==_ goto skip
set arr!count!=!tempvar!
set /a count=!count!+1
goto loop
:skip
echo out
echo display output
set arr
pause