Padleft function with a sequence number in PowerShell - powershell

Question

I need to add a progressive number of fixed length at the beginning of each row in a txt file. For example:
0001 aaaaaaaaaaa
0002 bbbbbbbbbb
...
0010 gggggggggg
I created a .bat file to run a PowerShell which should solve the problem:
#echo off &setlocal
set "path=C:\Users..."
set "filein=%~1"
set "fileout=%filein%_out"
setlocal EnableDelayedExpansion
call %SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe -Command "& {(Get-Content %path%\%filein%.txt) |ForEach-Object {$_.Insert(0,($id++).PadLeft(10,'0'))} |Set-Content %path%\%fileout%.txt}"
But it doesn't work. Probably there's some syntax error.

Answer 1

($id++).PadLeft(10,'0') fails, because ($id++) is of type [int], not [string], and [int] has no .PadLeft() method.
Simply converting ($id++) to a string is enough:
($id++).ToString().PadLeft(10,'0')
Also note that your sample output has a space between the padded number and the content of the line, so you'd have to use:
$_.Insert(0, ($id++).ToString().PadLeft(10,'0') + ' ')
As an aside:
You don't need call in a batch file to call executables (call is only needed for calling other batch files, if you want the call to return).
The PowerShell executable is in the %PATH% by default, so you can invoke it by name only, i.e., powershell.exe.

Answer 2

since you added the [batch-file] tag - here is a pure Batch solution:
#echo off
setlocal enabledelayedexpansion
set count=0
(for /f "delims=" %%A in (input.txt) do (
set /a count+=1
set "index=00000!count!"
echo !index:~-4! %%A
))>Output.txt

Answer 3

Something like this might workout for you -
$id = 1
$files = Get-Content "\\PathToYourFile\YourFile.txt"
foreach ($file in $files)
{
$Padded = $id.ToString("0000000000");
$file.Insert(0, ($Padded));
$id++
}
Use the ToString() method, instead of PadLeft to add progressive number of fixed length zeroes. That is much simpler and hassle-free.
Also, doing the entire operation in PowerShell will be much simpler.
You can also do this in a single line like -
$i = 1
Get-Content "\\PathToYourFile\YourFile.txt" | % { $_.Insert(0, ($i.ToString("0000000000"))); $i++ } | Set-Content ".\NewFileout.txt"

Answer 4

Here is a pure batch file solution, which does not ignore empty lines and is safe against all characters, even exclamantion marks (!):
#echo off
setlocal EnableExtensions DisableDelayedExpansion
set /A "IDX=0"
> "output.txt" (
for /F "delims=" %%L in ('findstr /N "^" "input.txt"') do (
set /A "IDX+=0"
set "LINE=%%L"
setlocal EnableDelayedExpansion
set "IDX=0000!IDX!"
echo !IDX:~-4! !LINE:*:=!
endlocal
)
)
endlocal
exit /B