I am trying to use a regex to find dates in a csv file and change the formatting because there are over 200 columns in this csv; manual column mapping for each date is not possible.
what I had previously was the following
$sf = '\\path\dept\Extracts\Date_Modified.csv'
$regex = "\d{1,2}/\d{1,2}/\d{4}"
(Get-Content $sf) |
Foreach-Object {$_ -replace $regex, (get-date -f "yyyy-MM-dd") } |
Set-Content $sf
that works fine if I want to replace all the dates with the current date, but that wasn't my goal. my goal is to recognize human entry type dates (mm/dd/yyyy) and change them to yyyy-mm-dd that the database table is expecting when I load the csv.
how can I modify this? or is there a better way to recognize date formats and change the format?
The answer: use capture groups. I don't know why you wouldn't be able to assign the regex to a variable before use (as I have done many times):
$sf = '\\path\dept\Extracts\Date_Modified.csv'
$regex = '(\d{1,2})\/(\d{1,2})\/(\d{4})'
#(Get-Content -Path $sf) |
ForEach-Object { $_ -replace $regex, '$3-$1-$2' } |
Set-Content -Path $sf
Of special note, use single-quotes in the replace statement so you don't end up trying to interpolate $1 into a (presumably null) variable.
Related
Am looking for some help to create a PowerShell script.
I have a folder where I have lots of files, I need only those file that has below two content inside it:
must have any matching string pattern as same as in file file1 (the content of file 1 is -IND 23042528525 or INDE 573626236 or DSE3523623 it can be more strings like this)
also have date inside the file in between 03152022 and 03312022 in the format mmddyyyy.
file could be old so nothing to do with creation time.
then save the result in csv containing the path of the file which fulfill above to conditions.
Currently am using the below command that only gives me the file which fulfilling the 1 condition.
$table = Get-Content C:\Users\username\Downloads\ISIN.txt
Get-ChildItem `
-Path E:\data\PROD\server\InOut\Backup\*.txt `
-Recurse |
Select-String -Pattern ($table)|
Export-Csv C:\Users\username\Downloads\File_Name.csv -NoTypeInformation
To test if a file contains a certain keyword from a range of keywords, you can use regex for that. If you also want to find at least one valid date in format 'MMddyyyy' in that file, you need to do some extra work.
Try below:
# read the keywords from the file. Ensure special characters are escaped and join them with '|' (regex 'OR')
$keywords = (Get-Content -Path 'C:\Users\username\Downloads\ISIN.txt' | ForEach-Object {[regex]::Escape($_)}) -join '|'
# create a regex to capture the date pattern (8 consecutive digits)
$dateRegex = [regex]'\b(\d{8})\b' # \b means word boundary
# and a datetime variable to test if a found date is valid
$testDate = Get-Date
# set two variables to the start and end date of your range (dates only, times set to 00:00:00)
$rangeStart = (Get-Date).AddDays(1).Date # tomorrow
$rangeEnd = [DateTime]::new($rangeStart.Year, $rangeStart.Month, 1).AddMonths(1).AddDays(-1) # end of the month
# find all .txt files and loop through. Capture the output in variable $result
$result = Get-ChildItem -Path 'E:\data\PROD\server\InOut\Backup'-Filter '*.txt'-File -Recurse |
ForEach-Object {
$content = Get-Content -Path $_.FullName -Raw
# first check if any of the keywords can be found
if ($content -match $keywords) {
# now check if a valid date pattern 'MMddyyyy' can be found as well
$dateFound = $false
$match = $dateRegex.Match($content)
while ($match.Success -and !$dateFound) {
# we found a matching pattern. Test if this is a valid date and if so
# set the $dateFound flag to $true and exit the while loop
if ([datetime]::TryParseExact($match.Groups[1].Value,
'MMddyyyy',[CultureInfo]::InvariantCulture,
[System.Globalization.DateTimeStyles]::None,
[ref]$testDate)) {
# check if the found date is in the set range
# this tests INCLUDING the start and end dates
$dateFound = ($testDate -ge $rangeStart -and $testDate -le $rangeEnd)
}
$match = $match.NextMatch()
}
# finally, if we also successfully found a date pattern, output the file
if ($dateFound) { $_.FullName }
elseif ($content -match '\bUNKNOWN\b') {
# here you output again, because unknown was found instead of a valid date in range
$_.FullName
}
}
}
# result is now either empty or a list of file fullnames
$result | set-content -Path 'C:\Users\username\Downloads\MatchedFiles.txt'
I'm still learning Powershell and in order to complete an assignment I need to convert written data in CSV files to a powershell accepted datetime format.
The dates in the CSV format are written as: 1-1-2014.
In order to convert them I found out (through a bit of brute force) that I can use the following code:
$Files = gci $Source\*.csv
$Data = Import-CSV $Files -Delimiter ";"
$Data | ForEach-Object { $_.Time = $_.Time -as [datetime]
$_
}
However, it would seem to me that this should work as well when written as follows:
$Data | ForEach-Object { $_.Time = $_.Time -as [datetime] $_ }
When I run it like that it returns a bunch of errors.
The $_ after [datetime] I also only added because a colleague used that in his functions, I don't really understand why it has to be put there, and why it needs to be put on a new line. Could anyone explain? If there is a different/better way to convert CSV data to a datetime format I'd be interested in hearing those as well, thanks in advance!
The first (multi-line) version works because PowerShell interprets a line-break after a complete statement as a terminator - it knows that $_ is a separate statement from $_.Time = $_.Time -as [datetime].
To place multiple separate statements on a single line, you'll have to use a semicolon ; to separate them:
$Data | ForEach-Object { $_.Time = $_.Time -as [datetime]; $_ }
I need your help with PowerShell.
I need Select-String with fixed Date (in variable). & Set-Content to result.txt
Example: $Date = "01.07.2020"
But also i need select string with date which lower than i written in variable.
My code: Get-Content -Path log.txt | Select-String "?????" | Set-Content $result.txt
In log.txt i have many strings like " Creation date 01.07.2020 " ; " Creation date 01.06.2020 "
123.txt
Creation date 01.07.2020
Creation date 02.05.2020
Creation date 01.06.2020
Creation date 28.08.2020
Example script
$file = "C:\Users\userprofile\Desktop\test\123.txt"
$regexpattern = "\d{2}\.\d{2}\.\d{4}"
$content = Get-Content $file | Where-object { $_ -match $regexpattern}
foreach($line in $content){
$line.Substring(13,11)
}
I used regex to find the lines you are wanting to output. We get the content only if it matches our regex, then for each line we found, I'm using substring to pull the date out. You could also put together a regex for this if you wanted to. Since we know the lines have the same number of characters it's safe to use the substring function.
If you want that output to a file, simply find $line.Substring(13,11) and then add this after it | Out-file "C:\Users\userprofile\desktop\test\output.txt" -append.
I have a Powershell script that I am trying to work out part of it, so the text input to this is listing the user group they are part of. This PS script is supposed to replace the group with the groups that I am assigning them in active directory(I am limited to only changing groups in active directory). My issue is that when it reaches HR and replaces it, it will then proceed to contine and replace all the new but it all so replaces the HR in CHRL, so my groups look nuts right now. But I am looking it over and it doesn't do it with every line. But for gilchrist it will put something in there for the HR in the name. Is there anything can I do to keep it for changing or am I going to have to change my HR to Human Resources? Thanks for the help.
$lookupTable = #{
'Admin' = 'W_CHRL_ADMIN_GS,M_CHRL_ADMIN_UD,M_CHRL_SITE_GS'
'Security' = 'W_CHRL_SECURITY_GS,M_CHRL_SITE_GS'
'HR' = 'M_CHRL_HR_UD,W_CHRL_HR_GS,M_CHRL_SITE_GS'
$original_file = 'c:\tmp\test.txt'
$destination_file = 'c:\tmp\test2.txt'
Get-Content -Path $original_file | ForEach-Object {
$line = $_
$lookupTable.GetEnumerator() | ForEach-Object {
if ($line -match $_.Key)
{
$line = $line -replace $_.Key, $_.Value
}
}
$line
} | Set-Content -Path $destination_file
Get-Content $destination_file
test.txt:
user,group
john.smith,Admin
joanha.smith,HR
john.gilchrist,security
aaron.r.smith,admin
abby.doe,secuity
abigail.doe,admin
Your input appears to be in CSV format (though note that your sample rows have trailing spaces, which you'd have to deal with, if they're part of your actual data).
Therefore, use Import-Csv and Export-Csv to read / rewrite your data, which allows a more concise and convenient solution:
Import-Csv test.txt |
Select-Object user, #{ Name='group'; Expression = { $lookupTable[$_.group] } } |
Export-Csv -NoTypeInformation -Encoding Utf8 test2.txt
Import-Csv reads the CSV file as a collection of custom objects whose properties correspond to the CSV column values; that is, each object has a .user and .name property in your case.
$_.group therefore robustly reports the abstract group name only, which you can directly pass to your lookup hashtable; Select-Object is used to pass the original .user value through, and to replace the original .group value with the lookup result, using a calculated property.
Export-Csv re-converts the custom objects to a CSV file:
-NoTypeInformation suppresses the (usually useless) data-type-information line at the top of the output file
-Encoding Utf8 was added to prevent potential data loss, because it is ASCII encoding that is used by default.
Note that Export-Csv blindly double-quotes all field values, whether they need it or not; that said, CSV readers should be able to deal with that (and Import-Csv certainly does).
As for what you tried:
The -replace operator replaces all occurrences of a given regex (regular expression) in the input.
Your regexes amounts to looking for (case-insensitive) substrings, which explains why HR matches both the HR group name and substring hr in username gilchrist.
A simple workaround would be to add assertions to your regex so that the substrings only match where you want them; e.g.: ,HR$ would only match after a , at the end of a line ($).
However, your approach of enumerating the hashtable keys for each input CSV row is inefficient, and you're better off splitting off the group name and doing a straight lookup based on it:
# Split the row into fields.
$fields = $line -split ','
# Update the group value (last field)
$fields[-1] = $lookupTable[$fields[-1]]
# Rebuild the line
$line = $fields -join ','
Note that you'd have to make an exception for the header row (e.g., test if the lookup result is empty and refrain from updating, if so).
Why don't you load your text file as a CSV file, using Import-CSV and use "," as a delimiter?
This will allow you to have a Powershell Object you can work on. and then export it as text o CSV. if I use your file & lookup table this code may help you :
$file = Import-Csv -Delimiter "," -Path "c:\ps\test.txt"
$lookupTable = #{
'Admin' = 'W_CHRL_ADMIN_GS,M_CHRL_ADMIN_UD,M_CHRL_SITE_GS'
'Security' = 'W_CHRL_SECURITY_GS,M_CHRL_SITE_GS'
'HR' = 'M_CHRL_HR_UD,W_CHRL_HR_GS,M_CHRL_SITE_GS'}
foreach ($i in $file) {
#Compare and replace
...
}
Export-CSV $file -Delimiter ","
You can then iterate over $file and compare and replace. you can also Export-CSV after you're done.
A nice tough one for you all. I'm trying to find and replace a given string in a bunch of files. The files have a date stamp in the file name i.e. YYYY_MM_DD_file.txt
I wish to search and replace within a date range for these files and then replace a string I define, I cannot use date modified as the date range, I must rely on the stamp in the filename.
So far I set my date range in WPF text fields:
$Filename = $Filenamebox.text
$startdate = [datetime] $startdatetext.text
$enddate = [datetime] $enddatetext.Text
$NewFilenamereal = $Newfilename.Text
$array =
do {
$startdate.ToString('yyyy_MM_dd*')
$startdate = $startdate.AddDays(1)
}
until ($startdate -gt [datetime] $enddate)
$files1 = $array | foreach-object {"C:\Users\michael.lawton\Desktop\KGB\Test folder\$_"}
write-host $files1
I then get child items using the $files1 array I have created as a search mask for the files in the date range and find all matches. Store this in a variable and replace the string $filename with the new string $Newfilenamereal.
$Matches1 = get-childitem $files1 | select-string $Filename | foreach-object {$_ -replace $Filename,$Newfilenamereal} | out-string
write-host $Matches1
However I cannot work out how to overwrite what has been found and replaced in the $Matches1 variable to the original files. I have tried set-content, however this will simply either erase everything I have in the date stamped files or cannot understand the $files1 array as a file path.
So my question to you lovely people is how do I write what I have replaced in the environment to the actual files?
Just retrieve the file content using the Get-Content cmdlet and replace the string. Finally write it back using the Set-Content cmdlet:
Get-ChildItem $files1 | ForEach-Object {
($_ | Get-Content -Raw) -replace $Filename,$Newfilenamereal |
Set-Content -Path $_.FullName -Encoding UTF8
}