SETLOCAL EnableDelayedExpansion
SET str=123456789abcdefgh
FOR /l %%x IN (1, 1, 10) DO (
SET /a intLength=10-%%x
SET result=!str:~-%%x!
ECHO "Works as intended: " !result!
SET result=!str:~-intLength!
ECHO "Does NOT work as intended: " !result!
)
endlocal
You're using the literal string intLength instead of the %intLength% variable.
Since you're initializing a variable inside of a for loop, you're going to have to use the !intLength! variation of this variable name. Unfortunately, since you're already using exclamation points to get the substring from str, you can't also use them in that line to get the value of intLength, since you'd then essentially have a variable !str:~!, an unrelated string that batch really isn't going to like, and a !!.
You can get around this by running !intLength! through another for loop and using the %%var variable instead, since you've already shown that that works.
#echo off
setlocal EnableDelayedExpansion
set str=123456789abcdefgh
for /l %%x in (1, 1, 10) DO (
set /a intLength=10-%%x
SET result=!str:~-%%x!
echo Works as intended: !result!
for /f %%A in ("!intLength!") do SET result=!str:~-%%A!
echo Now works as intended: !result!
echo.
)
endlocal
Related
My code is
FOR /F "skip=1 tokens=1-6" %%G IN ('WMIC Path Win32_LocalTime Get Day^,Hour^,Minute^,Month^,Second^,Year /Format:table') DO (
IF "%%~L"== "" goto s_done
Set _yyyy=%%L
Set _mm=00%%J
Set /a _nextmm=_mm+1
)
:s_done
What I want is this variable "_nextmm" = this variable "_mm" + 1
But when I run this code. It's result is
IF "2021" == "" goto s_done
Set _yyyy = 2021
Set _mm = 008
Set /a _nextmm = _mm+1
And I call echo %_nextmm%. The result is 1 instead of 009.
What did I do wrong in here?
I hope there are no SPACEs around the equal-to signs in your actual set command lines as they would harm. The best way is this syntax:
rem /* No spaces around `=`-sign, and quotes around the whole assignment expression,
rem which avoids unwanted training whitepsaces and protects special characters;
rem without assigning the quotes themselves to the variable value: */
set "VAR=Value"
Anyway, use:
set /A "_nextmm=%%J+1"
instead of set /A _nextmm=_mm+1, because (as I assume) %%J is 8, which is a correct decimal number, but _mm is 008, which is treated as an octal number due to the leading zeros (yes, I know, this is not intuitive, but take a look at this), which is invalid as there are only digits 0 to 7, hence 0 is taken for further arithmetic operations.
If you have your echo command line within the body of the for /F loop (so before the closing )), use:
for /F … (
…
call echo %%_nextmm%%
)
or use delayed variable expansion:
setlocal EnableDelayedExpansion
for /F … (
…
echo !_nextmm!
)
endlocal
If you have your echo command line outside of the body of the for /F loop (so after the closing )), normal or immediate expansion will work as expected:
for /F … (
…
)
echo %_nextmm%
TBH, I'm not sure of your logic, because if this was done in December 2021, then adding 1 would make the month incorrectly 13, and the year would remain as 2021.
For that reason, it would be much better if you just used PowerShell to assist you instead of WMIC. PowerShell sees dates as objects not strings, so you can perform the math directly in order to define the required values for your variables.
For /F "Tokens=1-2" %%G In ('
%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe -NoLogo -NoProfile
-Command "(Get-Date).AddMonths(1).ToString('yyyy MM')"') Do (Set "_yyyy=%%G"
Set "_MM=%%H")
If you wanted to do it without splitting the line up for better reading then:
For /F "Tokens=1-2" %%G In ('%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.exe -NoLogo -NoProfile -Command "(Get-Date).AddMonths(1).ToString('yyyy MM')"') Do Set "_yyyy=%%G" & Set "_MM=%%H"
Take this simple example:
#ECHO OFF
SET /P phrase="Enter Word : "
SET /a rnum=%random% %%10 +1
ECHO %phrase%
ECHO %rnum%
SET rchar=%phrase:~0,%rnum%%
ECHO %rchar%
Pause
I just want to be able to pass that rnum variable to pick that as the character chosen from the left of that user entered word to that random character.
I can't seem to figure out how to pass that as a variable.
I tried with enabledelayedexpansion with no luck:
#ECHO OFF
SET /P Phrase="Enter Word : "
SET /a rnum=%random% %%10 +1
ECHO %phrase%
ECHO %rnum%
setlocal enabledelayedexpansion
SET rchar=!phrase:~0,%rnum%!
endlocal
ECHO %rchar%
Pause
So how do I pass rnum as a variable in this instance? Thanks for any assistance.
Here's a simple modification of your example delayed expansion code, which shows one method of maintaining your variable value beyond endlocal:
#ECHO OFF
SET /P "phrase=Enter Word : "
SET /A rnum = %RANDOM% %% 10 + 1
ECHO %phrase%
ECHO %rnum%
SETLOCAL ENABLEDELAYEDEXPANSION
FOR %%G IN ("!phrase:~0,%rnum%!") DO ENDLOCAL & SET "rchar=%%~G"
ECHO rchar=%rchar%
PAUSE
The above example should be fine, as long as the end user does not begin to input strings with problematic characters. If you wanted to make it a little more robust for such scenarios then perhaps this will help:
#Echo Off
SetLocal EnableExtensions DisableDelayedExpansion
:AskString
Rem Get interactive string input
Set "String="
Set /P String="Enter Word : "
If Not Defined String GoTo AskString
Set String
Rem Generate a random integer 1..10
Set /A "Integer = (%RANDOM% %% 10) + 1"
Set Integer
Rem Create a substring variable using %String% and %Integer%
Echo %%SubString%% = %%String:~0,%Integer%%%
SetLocal EnableDelayedExpansion
For /F Delims^=^ EOL^=^ UseBackQ %%G In ('"!String:~0,%Integer%!"') Do (
EndLocal
Set "SubString=%%~G"
)
Set SubString
Pause
Please note that the above code uses Set Variable to display the variable name along side its value. If your variable contains certain poison characters just using Echo %Variable% may not work, and you would probably be better off keeping delayed expansion enabled at that time.
As Compo already comments, the position of your endlocal is the problem.
You could just move the endlocal after the echo
#ECHO OFF
setlocal enabledelayedexpansion
SET /P Phrase="Enter Word : "
SET /a rnum=%random% %%10 +1
ECHO !phrase!
ECHO !rnum!
SET "rchar=!phrase:~0,%rnum%!"
ECHO !rchar!
endlocal
In a for each loop, I'm trying to perform a task on each iteration except the first. This is my attempt
#echo off
set sources=file1.txt file2.txt
set output=output.txt
set comment_prefix=--
break>%output%
setlocal EnableDelayedExpansion
set first=1
for %%a in (%sources%) do (
if %first%==0 (
echo.>> %output%
echo.>> %output%
echo.>> %output%
)
set first=0
echo %first%
echo %comment_prefix%>>%output% %%a
echo.>> %output%
type %%a>>%output%
)
The problem is that the variable first seems to be constantly set to 1, even though it should be set to 0 after the first iteration (I think)...
How can I make the value of first change to zero?
Is there a better way to make a condition to check if the iteration is not the first one?
Cheers
EDIT:
This is the current output
1
1
You are setting and expanding (reading) the variable within the same line or block of code, so you need delayed expansion. Otherwise, %first% will expand to the value the variable was set to at the time the entire line/block is parsed (so the variable is in fact set, but an old value is read). To use delayed expansion, replace %first% by !first!.
However, since you are using the variable as a boolean flag only, you could reflect the boolean False by an empty variable rather than by the value 0, so you could use if not defined first instead of if !first!==0, which delayed expansion is not necessary for:
set "first=1"
for %%a in (%sources%) do (
if not defined first (
echo.>> %output%
echo.>> %output%
echo.>> %output%
)
set "first="
echo %comment_prefix%>>%output% %%a
echo.>> %output%
type %%a>>%output%
)
When running the following code in a windows batch file everything works aside from the string containing the asterisk, which is skipped. Checking the passed parameters by number (i.e. echo(%~6) I can see the asterisk - it's only when passed to the FOR loop that I have an issue:
#echo off
setlocal enableextensions enabledelayedexpansion
call:Concat cmd "this is a demo" " of concat functionality." " Hopefully it will work;" " but it doesn't when I pass an" " * asterisk" " character"
echo !cmd!
#goto:end
#goto:eof
:Concat
::Concatenates a given list of strings without including their quotes
::1 - output variable
::2* - strings to concat
echo(%*
set /a xx=0
set Concat_tempFlag=0
set Concat_temp=
for %%A in (%*) do (
set /a xx=!xx!+1
echo !xx! - %%A
if !Concat_tempFlag!==1 (
set Concat_temp=!Concat_temp!%%~A
) else (
set Concat_tempFlag=1
)
)
set "%~1="%Concat_temp%""
#goto:eof
:End
echo(Bye
exit /b 0
I've attempted for /F (tokens=*) %%A in ('echo(%*') do ( as suggested here: Batch FOR loop with asterisk (and variations thereof) but with no luck. Any ideas? Thanks in advance.
Found the solution here: I need to match or replace an asterisk * in a batch environmental variable using only native Windows commands. Is this possible?
Full code below:
#echo off
setlocal enableextensions enabledelayedexpansion
set DEFAULT_AsteriskMarker=_xAsteriskMarkerx_
call:Concat cmd "this is a demo" " of concat functionality." " Hopefully it will work;" " but it doesn't when I pass an" " * asterisk" " character"
echo !cmd!
#goto:end
#goto:eof
:Concat
::Concatenates a given list of strings without including their quotes
::1 - output variable
::2* - strings to concat
set Concat_StringsToConcat=%*
echo(%Concat_StringsToConcat%
call:AsteriskFix Concat_StringsToConcat
set /a xx=0
set Concat_tempFlag=0
set Concat_temp=
for %%A in (%Concat_StringsToConcat%) do (
set /a xx=!xx!+1
echo !xx! - %%A
if !Concat_tempFlag!==1 (
set Concat_temp=!Concat_temp!%%~A
) else (
set Concat_tempFlag=1
)
)
set "%~1="!Concat_temp:%DEFAULT_AsteriskMarker%=*!"
#goto:eof
:AsteriskFix
::https://stackoverflow.com/questions/11685375/i-need-to-match-or-replace-an-asterisk-in-a-batch-environmental-variable-using
set AsteriskFix_temp=!%~1!
if "%~2"=="" (
set AsteriskFix_marker=%DEFAULT_AsteriskMarker%
) else (
set AsteriskFix_marker=%~2
)
call:StrLen AsteriskFix_temp AsteriskFix_len
for /l %%x in (0,1,%AsteriskFix_len%) do if not "!AsteriskFix_temp:~%%x,1!"=="" if "!AsteriskFix_temp:~%%x,1!"=="*" (
set /a AsteriskFix_plusone=%%x+1
for /l %%y in (!AsteriskFix_plusone!, 1, !AsteriskFix_plusone!) do (
set AsteriskFix_temp=!AsteriskFix_temp:~0,%%x!%AsteriskFix_marker%!AsteriskFix_temp:~%%y!
)
)
set "%~1=!AsteriskFix_temp!"
#goto:eof
:StrLen
::http://www.dostips.com/DtCodeCmdLib.php#strLen
set "StrLen_str=A!%~1!" &:: keep the A up front to ensure we get the length and not the upper bound
::it also avoids trouble in case of empty string
set "StrLen_len=0"
for /L %%A in (12,-1,0) do (
set /a "StrLen_len|=1<<%%A"
for %%B in (!StrLen_len!) do if "!StrLen_str:~%%B,1!"=="" set /a "StrLen_len&=~1<<%%A"
)
IF "%~2" NEQ "" SET /a %~2=%StrLen_len%
#goto:eof
:End
echo(Bye
exit /b 0
Thanks to James K
The link you provided leads to the right answer:
There is no way to preserve an asterisk (nor a question mark) in the set of a normal (no /F option) FOR command (they are always changed to file names); you need to separate the parameters in a FOR /F command. If you also want to process each parameter in a FOR loop, then the second FOR can NOT be in the same context, so you must CALL a subroutine to change the context
If I know that one environment variable contains the name of another, how can I get the value of the second environment variable?
Assume I have a file java.properties alongside my batch file with the following contents.
JAVA_HOME_OVERRIDE_ENV_VAR=JAVA_HOME_1_7_0_17
What I want to do is check if JAVA_HOME_1_7_0_17 is set and, if so, do the equivalent of set JAVA_HOME=%JAVA_HOME_1_7_0_17%. I can figure out what environment variable I'm looking for, but I don't know how to get its value. This is what I have so far...
#echo off
setlocal enabledelayedexpansion
if exist %~dp0\java.properties (
echo "Found java properties."
for /F "tokens=1* usebackq delims==" %%A IN (%~dp0\java.properties) DO (
if "%%A"=="JAVA_HOME_OVERRIDE_ENV_VAR" set JAVA_HOME_OVERRIDE_ENV_VAR=%%B
)
if not [!JAVA_HOME_OVERRIDE_ENV_VAR!] == [] (
echo "Override var is !JAVA_HOME_OVERRIDE_ENV_VAR!"
REM This is where I'm stuck!!!
REM Assume JAVA_HOME_OVERRIDE_ENV_VAR is JAVA_HOME_1_7_0_17
)
)
endlocal & set JAVA_HOME=%JAVA_HOME%
What I want to do is check if the environment variable JAVA_HOME_1_7_0_17 exists and, if it does, use its value to set JAVA_HOME.
Updated
I think the nested if statements are making things more difficult then needed. I got rid of them and the following seems to work.
#echo off
setlocal enabledelayedexpansion
if not exist "%~dp0\java.properties" (
goto:EOF
)
for /F "tokens=1* usebackq delims==" %%A IN ("%~dp0\java.properties") DO (
if "%%A"=="JAVA_HOME_OVERRIDE_ENV_VAR" set JAVA_HOME_OVERRIDE_ENV_VAR=%%B
)
if [!JAVA_HOME_OVERRIDE_ENV_VAR!] == [] (
goto:EOF
)
set JAVA_HOME=!%JAVA_HOME_OVERRIDE_ENV_VAR%!
endlocal & set JAVA_HOME="%JAVA_HOME%"
Try set JAVA_HOME=%!JAVA_HOME_OVERRIDE_ENV_VAR!%.
EDIT: This should not work if !JAVA_HOME_OVERRIDE_ENV_VAR! was set on the same line. Try
call set JAVA_HOME=!%JAVA_HOME_OVERRIDE_ENV_VAR%!
a downside being that since it will search the disk for a file/executable with the name set, the command should take slightly longer to finish, though it should only be noticeable in large loops.
EDIT 2: Try this too...
(add set override=0 in front, add set override=1 under if not, and replace the endlocal line)
#echo off
setlocal enabledelayedexpansion
set override=0
if exist %~dp0\java.properties (
echo "Found java properties."
for /F "tokens=1* usebackq delims==" %%A IN (%~dp0\java.properties) DO (
if "%%A"=="JAVA_HOME_OVERRIDE_ENV_VAR" set JAVA_HOME_OVERRIDE_ENV_VAR=%%B
)
if not [!JAVA_HOME_OVERRIDE_ENV_VAR!] == [] (
echo "Override var is !JAVA_HOME_OVERRIDE_ENV_VAR!"
set override=1
REM Assume JAVA_HOME_OVERRIDE_ENV_VAR is JAVA_HOME_1_7_0_17
)
)
endlocal & if override=1 set JAVA_HOME=!%JAVA_HOME_OVERRIDE_ENV_VAR%!
I would use FINDSTR to filter out the relevant line, IF DEFINED to validate the existence of the variable, and delayed expansion within the loop to get the appropriate value.
Your code could be as simple as:
#echo off
setlocal enableDelayedExpansion
for /f "tokens=1* delims==" %%A in (
'2^>nul findstr /bil "JAVA_HOME_OVERRIDE_ENV_VAR=" "%~dp0\java.properties"'
) do if defined %%B set "JAVA_HOME=!%%B!"
endlocal & set "JAVA_HOME=%JAVA_HOME%"