127} How can I pad leading zeros or like to a variable?
The solution already is embedded within a couple of items in this
FAQ collection, but let's revisit the question and make it a separate
item. The code below adds leading zeros to the replaceable parameter
%1 making it exactly
five characters long.
@echo off & setlocal enableextensions
set var_=
00000%1
set var_=%var_
:~-5%
echo %var_%
endlocal & goto :EOF
The output could be e.g.
C:\_D\TEST>cmdfaq 23
00023
or
C:\_D\TEST>cmdfaq 12345678
45678
Written much more generally with a subroutine we can have
@echo off & setlocal enableextensions
if "%~1"=="" (
echo Usage: %~0 MyTestString
goto :EOF)
call :LeadVar "%~1" 0 5 padded_
echo.%padded_%
endlocal & goto :EOF
::
:: ===============================================================
:: Subroutine: A generic padding of a string
:LeadVar MyString PadWith MaxLength return_
setlocal enableextensions enabledelayedexpansion
set PadWith=%~2
set MaxLength=%~3
for /L %%a in (1,1,%MaxLength%) do set MyString=!MyString!!PadWith!
set MyString=%MyString%%~1
set return_=!MyString:~-%MaxLength%!
endlocal & set "%~4=%return_%" & goto :EOF
An example of the output:
C:\_D\TEST>cmdfaq "12 4"
012 4
See the usage FuncRightJustify function which is part
of the WHEREIS.CMD script included in this collection. (It uses
spaces instead of zeros.) Useful for justifying columns.
:FuncRightJustify arg1 arg2
setlocal enableextensions
set number_= %1
set number_=%number_:~-12%
endlocal & set "%2=%number_%" & goto :EOF
Just for the sake of interest, let's write also a
G(nu)AWK
solution to the problem.
@echo off & setlocal enableextensions
set var_=00000%1
echo %var_%|gawk '{printf "@set var_=%%05d\n",$0}'>"%TEMP%\tmp$$$.cmd"
for %%c in (call del) do %%c "%TEMP%\tmp$$$.cmd"
echo %var_%
endlocal & goto :EOF
The gawk snippet could be formulated in other ways as well. For example
the more complicated
gawk '{i="00000"$1}{p=length(i)}{printf "@set var_=%%s\n",substr(i,p-4,p)}
The task can for further demonstration be also solved with a
VBScipt-aided formulation:
@echo off & setlocal enableextensions
::
set var_=%~1
::
:: Build a Visual Basic Script
set skip=
set temp_=%temp%
if defined mytemp if exist "%mytemp%\" set temp_=%mytemp%
set vbs_=%temp_%\tmp$$$.vbs
>"%vbs_%" findstr "'%skip%VBS" "%~f0"
::
:: Run the script with Microsoft Windows Script Host Version 5.6
for /f "tokens=*" %%a in ('
cscript //nologo "%vbs_%" "%var_%"') do (
set paddedvar_=%%a)
::
:: Display the result
echo %paddedvar_%
::
:: Clean up
for %%f in ("%vbs_%") do if exist %%f del %%f
endlocal & goto :EOF
'
'The Visual Basic Script
Set arg = WScript.Arguments 'VBS
Wscript.Echo PadFn(arg(0),
5) 'VBS
'
Function PadFn (str, n) 'VBS
PadFn = Right(String(n-1,"0")&str,n) 'VBS
End Function 'VBS
The output could be e.g.
C:\_D\TEST>cmdfaq 23
00023
or
C:\_D\TEST>cmdfaq 12345678
45678
, we might wish to have
Function PadFn (str, n) 'VBS
If Len(str) > n Then 'VBS
PadFn = str 'VBS
Else 'VBS
PadFn = Right(String(n-1,"0")&str,n) 'VBS
End If 'VBS
End Function 'VBS
The output could be e.g.
C:\_D\TEST>cmdfaq 23
00023
or
C:\_D\TEST>cmdfaq 12345678
12345678
A brief way of writing the VBS-aided solution
@echo off & setlocal enableextensions
set var_=%~1
echo %var_%
>"%temp%\tmp$$$.vbs" echo WScript.Echo Right(String(5-1,"0")^&"%var_%",5)
for /f "tokens=* delims=" %%a in (
'cscript //nologo "%temp%\tmp$$$.vbs"') do set var_=%%a
for %%f in ("%temp%\tmp$$$.vbs") do if exist %%f del %%f
echo %var_%
endlocal & goto :EOF
The output could be e.g.
C:\_D\TEST>cmdfaq 23
23
00023
or
C:\_D\TEST>cmdfaq 12345678
12345678
45678
Assorted NT/2000/XP/.. CMD.EXE Script Tricks
