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Powershell: Padding a string

I'm reading a csv file that has already process a date in the format MMDDYYYY. However, for single-digit months, there is no leading 0. I'd like to "pad" this string so that there's a leading 0.

I know I can do something like this

$file = import-csv c:\temp\myfile.csv

foreach ($line in $file) {
   $date = $line.DATE 
   if($date.Length -lt 8){
       $date = -Join ("0",$date)
    } else {
        # date length is good; do nothing
    }
}

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I'm looking for the most efficient way to do this (less code as possible)
Thx

Meir Rivkin

simply parse the date instead of checking
length and stuff:

$file = import-csv c:\temp\myfile.csv

foreach ($line in $file) {
$date = $line.DATA
$date = [DateTime]::Parse($date).ToString("MMDDYYYY")

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bndit

ASKER

what am I doing wrong? See snapshot attached to see how I'm running it (straight on the shell)

Exception calling "Parse" with "1" argument(s): "String was not recognized as a valid DateTime."
At line:1 char:18
+ [DateTime]::Parse <<<< ($date).ToString("MMDDYYYY")
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : DotNetMethodException
date.png

Meir Rivkin

sorry for the confusion, parse and parseExact can't deal with single digit month even when explicitly defined:

$date = "6102013"
$date = [DateTime]::ParseExact($date, "Mddyyyy",[System.Globalization.CultureInfo]::CurrentCulture)

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also in several places i found that ppl use similar methods to detect single digits months (or days) and simply pad with 0 to work with DateTime objects.
you can shorten your line by doing this:

$file = import-csv c:\temp\myfile.csv
foreach ($line in $file) {
  [DateTime]$date = @{$true=("0"+$line.DATE);$false=$line.DATE}[$line.DATE.Length -lt 8] 
}

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bndit

ASKER

This article would make me think I could use the static method ParseExact
http://dusan.kuzmanovic.net/2012/05/07/powershell-parsing-date-and-time/

do you know why it's not working?

Meir Rivkin

I tested parseExact it wont work with single digit month

Qlemo

How about

foreach ($line in import-csv c:\temp\myfile.csv) {
   $date = $line.DATE.PadLeft(8, '0') 
}

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import-csv c:\temp\myfile.csv | % { $date = $_.Date.PadLeft(8, '0') }

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bndit

ASKER

Thanks for trying, but I think it's going to be really hard to convert dates given to me in this format since a 1-digit month and 1-digit day are used. Padding left would yield incorrect dates where the date is 1-digit (i.e. 1271950 would yield 01271950 but I really want 12071950).

SOLUTION

Qlemo

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ASKER CERTIFIED SOLUTION

Aard Vark

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