Modify CSV file to add a digit character to a column - batch-file

Question

I have a problem making a batch file.
This text is inside a file with name export.dat and I have no means to change the CSV field item from 5 to 6 digits.
This is a preferred older program.
As for newer program I can add the required.
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00,07833,300.00,078330
Has to be after modification:
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,078330,300.00,078330 - A03.1 - Shigellosis d,,etc
So we have a leading capital D followed by 13 commas and batch should ad a zero before the comma 13.

Answer 1

#echo off
setlocal
set "target=.\export.dat"
set "destination=.\updated.dat"
powershell -noprofile -command^
"$content = get-content -literalpath '%target%';"^
"$modifiedContent = #();"^
"$modifiedContent += $content[0];"^
"ForEach ($line in $content[1 .. ($content.count - 1)]) {"^
" if ($line.startswith('D,')) {"^
" $items = $line.split(',');"^
" if ($items.length -gt 14) {$items[14] += '0'; $line = $items -join ','};"^
" };"^
" $modifiedContent += $line"^
"};"^
"$modifiedContent | set-content -literalpath '%destination%'"
Powershell has Import-CSV and Export-CSV which can handle CSV files, though Export-CSV outputs data with double quoted field items. Powershell 7 introduces arguments for quotes for Export-CSV, though is still new at this time. With Powershell less than 7, the suggestions are to read the file with Get-Content, remove double quotes and use Set-Content. Since the example content lacks double quotes, I decided to use Get-Content, split on commas and write with Set-Content.
The following code is a hybrid batch-file with powershell which I used as a basis to construct the previous code.
It has some comments that explains the code which is not suitable for inserting into a single powershell command.
<# :: Begin bat code
#echo off
setlocal
set "target=.\export.dat"
set "destination=.\updated.dat"
powershell -noprofile "invoke-expression(get-content '%~f0' | out-string)"
exit /b 0
#> ## Begin ps1 code
# Filepaths from environment variables.
$target = $env:target
$destination = $env:destination
# Read file content into a variable.
$content = get-content -literalpath $target
# Create an empty array for modified content.
$modifiedContent = #()
# Add 1st line as unmodified header.
$modifiedContent += $content[0]
# Add the rest of the lines.
foreach ($line in $content[1 .. ($content.length - 1)]) {
# Require a leading capital D to modify a line.
if ($line.startswith('D,')) {
# Split by commas.
$items = $line.split(',')
# Modify item 14.
if ($items.length -gt 14) {
$items[14] += '0'
$line = $items -join ','
}
}
# Add line to array.
$modifiedContent += $line
}
# Write modified content to destination file.
$modifiedContent | set-content -literalpath $destination
If suitable, the powershell code portion could be copied to a .ps1 file and just replace $target = $env:target and $destination = $env:destination with $target = '.\export.dat' and $destination = '.\updated.dat'.
Input export.dat:
0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00,07833,300.00,078330
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00
d,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00,07833,300.00,078330
Output updated.dat:
0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00,078330,300.00,078330
D,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00
d,1,2126,4372,T,125P,,255473730,person,n,person,19800320,07833,300.00,07833,300.00,078330
1st line is the header unmodified.
2nd line is modified.
3rd line is too short in length to modify.
4th line does not start with D, as d, does not match same case so is not modified.