I have a string that I want to split up in 2 pieces. The first piece is before the comma (,) and the second piece is all stuff after the comma (including the commas).
I already managed to retrieve the first piece before the comma in the variable $Header, but I don't know how to retrieve the pieces after the first comma in one big string.
$string = "Header text,Text 1,Text 2,Text 3,Text 4,"
$header = $string.Split(',')[0] # $Header = "Header text"
$content = "Text 1,Text 2,Text 3,Text 4,"
# There might be more text then visible here, like say Text 5, Text 6, ..
PowerShell's -split operator supports specifying the maximum number of sub-strings to return, i.e. how many sub-strings to return. After the pattern to split on, give the number of strings you want back:
$header,$content = "Header text,Text 1,Text 2,Text 3,Text 4," -split ',',2
Try something like :
$Content=$String.Split([string[]]"$Header,", [StringSplitOptions]"None")[1]
As you split according to a String, you are using a different signature of the function split.
The basic use needs only 1 argument, a separator character (more info about it can be found here, for instance). However, to use strings, the signature is the following :
System.String[] Split(String[] separator, StringSplitOptions options)
This is why you have to cast your string as an array of string. We use the None option in this case, but you can find the other options available in the split documentation.
Finally, as the value of $Heasder, is at the beggining of your $String, you need to catch the 2nd member of the resulting array.
method of Aaron is the best, but i propose my solution
$array="Header text,Text 1,Text 2,Text 3,Text 4," -split ','
$array[0],($array[1..($array.Length -1)] -join ",")
This alternate solution makes use of PowerShell's ability to distribute arrays to multiple variables with a single assignment. Note, however, that the -split operator splits on every comma and PowerShell's built-in conversion from Array back to String results in the elements being concatenated back together. So it's not as efficient as String.Split, but in your example, it's negligible.
$OFS = ','
$Content = 'Header text,Text 1,Text 2,Text 3,Text 4,'
[String]$Header,[String]$Rest = $Content -split $OFS
$OFS = ' '
Write-Host "Header = $Header"
Write-Host "Rest = $Rest"
Finally, $OFS is a special variable in PowerShell that determines which character will be used when joining the array elements back into a single string. By default, it's a space. But it can be changed to anything.
Related
I have the following code:
$DatabaseSettings = #();
$NewDatabaseSetting = "" | select DatabaseName, DataFile, LogFile, LiveBackupPath;
$NewDatabaseSetting.DatabaseName = "LiveEmployees_PD";
$NewDatabaseSetting.DataFile = "LiveEmployees_PD_Data";
$NewDatabaseSetting.LogFile = "LiveEmployees_PD_Log";
$NewDatabaseSetting.LiveBackupPath = '\\LiveServer\LiveEmployeesBackups';
$DatabaseSettings += $NewDatabaseSetting;
When I try to use one of the properties in a string execute command:
& "$SQlBackupExePath\SQLBackupC.exe" -I $InstanceName -SQL `
"RESTORE DATABASE $DatabaseSettings[0].DatabaseName FROM DISK = '$tempPath\$LatestFullBackupFile' WITH NORECOVERY, REPLACE, MOVE '$DataFileName' TO '$DataFilegroupFolder\$DataFileName.mdf', MOVE '$LogFileName' TO '$LogFilegroupFolder\$LogFileName.ldf'"
It tries to just use the value of $DatabaseSettings rather than the value of $DatabaseSettings[0].DatabaseName, which is not valid.
My workaround is to have it copied into a new variable.
How can I access the object's property directly in a double-quoted string?
When you enclose a variable name in a double-quoted string it will be replaced by that variable's value:
$foo = 2
"$foo"
becomes
"2"
If you don't want that you have to use single quotes:
$foo = 2
'$foo'
However, if you want to access properties, or use indexes on variables in a double-quoted string, you have to enclose that subexpression in $():
$foo = 1,2,3
"$foo[1]" # yields "1 2 3[1]"
"$($foo[1])" # yields "2"
$bar = "abc"
"$bar.Length" # yields "abc.Length"
"$($bar.Length)" # yields "3"
PowerShell only expands variables in those cases, nothing more. To force evaluation of more complex expressions, including indexes, properties or even complete calculations, you have to enclose those in the subexpression operator $( ) which causes the expression inside to be evaluated and embedded in the string.
#Joey has the correct answer, but just to add a bit more as to why you need to force the evaluation with $():
Your example code contains an ambiguity that points to why the makers of PowerShell may have chosen to limit expansion to mere variable references and not support access to properties as well (as an aside: string expansion is done by calling the ToString() method on the object, which can explain some "odd" results).
Your example contained at the very end of the command line:
...\$LogFileName.ldf
If properties of objects were expanded by default, the above would resolve to
...\
since the object referenced by $LogFileName would not have a property called ldf, $null (or an empty string) would be substituted for the variable.
Documentation note: Get-Help about_Quoting_Rules covers string interpolation, but, as of PSv5, not in-depth.
To complement Joey's helpful answer with a pragmatic summary of PowerShell's string expansion (string interpolation in double-quoted strings ("...", a.k.a. expandable strings), including in double-quoted here-strings):
Only references such as $foo, $global:foo (or $script:foo, ...) and $env:PATH (environment variables) can directly be embedded in a "..." string - that is, only the variable reference itself, as a whole is expanded, irrespective of what follows.
E.g., "$HOME.foo" expands to something like C:\Users\jdoe.foo, because the .foo part was interpreted literally - not as a property access.
To disambiguate a variable name from subsequent characters in the string, enclose it in { and }; e.g., ${foo}.
This is especially important if the variable name is followed by a :, as PowerShell would otherwise consider everything between the $ and the : a scope specifier, typically causing the interpolation to fail; e.g., "$HOME: where the heart is." breaks, but "${HOME}: where the heart is." works as intended.
(Alternatively, `-escape the :: "$HOME`: where the heart is.", but that only works if the character following the variable name wouldn't then accidentally form an escape sequence with a preceding `, such as `b - see the conceptual about_Special_Characters help topic).
To treat a $ or a " as a literal, prefix it with escape char. ` (a backtick); e.g.:
"`$HOME's value: $HOME"
For anything else, including using array subscripts and accessing an object variable's properties, you must enclose the expression in $(...), the subexpression operator (e.g., "PS version: $($PSVersionTable.PSVersion)" or "1st el.: $($someArray[0])")
Using $(...) even allows you to embed the output from entire commands in double-quoted strings (e.g., "Today is $((Get-Date).ToString('d')).").
Interpolation results don't necessarily look the same as the default output format (what you'd see if you printed the variable / subexpression directly to the console, for instance, which involves the default formatter; see Get-Help about_format.ps1xml):
Collections, including arrays, are converted to strings by placing a single space between the string representations of the elements (by default; a different separator can be specified by setting preference variable $OFS, though that is rarely seen in practice) E.g., "array: $(#(1, 2, 3))" yields array: 1 2 3
Instances of any other type (including elements of collections that aren't themselves collections) are stringified by either calling the IFormattable.ToString() method with the invariant culture, if the instance's type supports the IFormattable interface[1], or by calling .psobject.ToString(), which in most cases simply invokes the underlying .NET type's .ToString() method[2], which may or may not give a meaningful representation: unless a (non-primitive) type has specifically overridden the .ToString() method, all you'll get is the full type name (e.g., "hashtable: $(#{ key = 'value' })" yields hashtable: System.Collections.Hashtable).
To get the same output as in the console, use a subexpression in which you pipe to Out-String and apply .Trim() to remove any leading and trailing empty lines, if desired; e.g.,
"hashtable:`n$((#{ key = 'value' } | Out-String).Trim())" yields:
hashtable:
Name Value
---- -----
key value
[1] This perhaps surprising behavior means that, for types that support culture-sensitive representations, $obj.ToString() yields a current-culture-appropriate representation, whereas "$obj" (string interpolation) always results in a culture-invariant representation - see this answer.
[2] Notable overrides:
• The previously discussed stringification of collections (space-separated list of elements rather than something like System.Object[]).
• The hashtable-like representation of [pscustomobject] instances (explained here) rather than the empty string.
#Joey has a good answer. There is another way with a more .NET look with a String.Format equivalent, I prefer it when accessing properties on objects:
Things about a car:
$properties = #{ 'color'='red'; 'type'='sedan'; 'package'='fully loaded'; }
Create an object:
$car = New-Object -typename psobject -Property $properties
Interpolate a string:
"The {0} car is a nice {1} that is {2}" -f $car.color, $car.type, $car.package
Outputs:
# The red car is a nice sedan that is fully loaded
If you want to use properties within quotes follow as below. You have to use $ outside of the bracket to print property.
$($variable.property)
Example:
$uninstall= Get-WmiObject -ClassName Win32_Product |
Where-Object {$_.Name -like "Google Chrome"
Output:
IdentifyingNumber : {57CF5E58-9311-303D-9241-8CB73E340963}
Name : Google Chrome
Vendor : Google LLC
Version : 95.0.4638.54
Caption : Google Chrome
If you want only name property then do as below:
"$($uninstall.name) Found and triggered uninstall"
Output:
Google Chrome Found and triggered uninstall
I have a regular expression that I use several times in a script, where a single word gets changed but the rest of the expression remains the same. Normally I handle this by just creating a regular expression string with a format like the following example:
# Simple regex looking for exact string match
$regexTemplate = '^{0}$'
# Later on...
$someString = 'hello'
$someString -match ( $regexTemplate -f 'hello' ) # ==> True
However, I've written a more complex expression where I need to insert a variable into the expression template and... well regex syntax and string formatting syntax begin to clash:
$regexTemplate = '(?<=^\w{2}-){0}(?=-\d$)'
$awsRegion = 'us-east-1'
$subRegion = 'east'
$awsRegion -match ( $regexTemplate -f $subRegion ) # ==> Error
Which results in the following error:
InvalidOperation: Error formatting a string: Index (zero based) must be greater than or equal to zero and less than the size of the argument list.
I know what the issue is, it's seeing one of my expression quantifiers as a replacement token. Rather than opt for a string-interpolation approach or replace {0} myself, is there a way I can tell PowerShell/.NET to only replace the 0-indexed token? Or is there another way to achieve the desired output using format strings?
If a string template includes { and/or } characters, you need to double these so they do not interfere with the numbered placeholders.
Try
$regexTemplate = '(?<=^\w{{2}}-){0}(?=-\d$)'
I am trying to convert values under 'key' column to a single string delimited with ','
$TheTable = (get-command get-mailbox).Parameters
Command returns:
Key Value
--- -----
ErrorAction System.Management.Automation.ParameterMetadata
IncludeInactiveMailbox System.Management.Automation.ParameterMetadata
Verbose System.Management.Automation.ParameterMetadata
OutVariable System.Management.Automation.ParameterMetadata
I am trying to achieve:
$TheTable = "ErrorAction,IncludeInactiveMailbox,Verbose,OutVariable"
I am completely lost as everything I attempt (foreach loop, .ToString) returns:
System.Collections.Generic.Dictionary`2[System.String,System.Management.Automation.ParameterMetadata],
Is there any way too do that?
To get a hashtable's / dictionary's keys, use its .Keys property.
To convert a collection of strings to a single string with a separator, use the -join operator.
Therefore:
$TheTable = (get-command get-mailbox).Parameters.Keys -join ","
I have a fairly long string in PowerShell that I need to split. Each section begins with a date in format mm/dd/yyyy hh:mm:ss AM. Essentially what I am trying to do is get the most recent message in the string. I don't need to keep the date/time part as I already have that elsewhere.
This is what the string looks like:
10/20/2018 1:22:33 AM
Some message the first one in the string
It can be several lines long
With multiple line breaks
But this is still the first message in the string
10/21/2018 4:55:11 PM
This would be second message
Same type of stuff
But its a different message
I know how to split a string on specific characters, but I don't know how on a pattern like date/time.
Note:
The solution below assumes that the section are not necessarily chronologically ordered so that you must inspect all time stamps to determine the most recent one.
If, by contrast, you can assume that the last message is the most recent one, use LotPings' much simpler answer.
If you don't know ahead of time what section has the most recent time stamp, a line-by-line approach is probably best:
$dtMostRecent = [datetime] 0
# Split the long input string ($longString) into lines and iterate over them.
# If input comes from a file, replace
# $longString -split '\r?\n'
# with
# Get-Content file.txt
# If the file is large, replace the whole command with
# Get-Content file.txt | ForEach-Object { ... }
# and replace $line with $_ in the script block (loop body).
foreach ($line in $longString -split '\r?\n') {
# See if the line at hand contains (only) a date.
if ($dt = try { [datetime] $line } catch {}) {
# See if the date at hand is the most recent so far.
$isMostRecent = $dt -ge $dtMostRecent
if ($isMostRecent) {
# Save this time stamp as the most recent one and initialize the
# array to collect the following lines in (the message).
$dtMostRecent = $dt
$msgMostRecentLines = #()
}
} elseif ($isMostRecent) {
# Collect the lines of the message associated with the most recent date.
$msgMostRecentLines += $line
}
}
# Convert the message lines back into a single, multi-line string.
# $msgMostRecent now contains the multi-line message associated with
# the most recent time stamp.
$msgMostRecent = $msgMostRecentLines -join "`n"
Note how try { [datetime] $line } catch {} is used to try to convert a line to a [datetime] instance and fail silently, if it can't, in which case $dt is assigned $null, which in a Boolean context is interpreted as $False.
This technique works irrespective of the culture currently in effect, because PowerShell's casts always use the invariant culture when casting from strings, and the dates in the input are in one of the formats the invariant culture understands.
By contrast, the -as operator, whose use would be more convenient here - $dt =$line -as [datetime] - unexpectedly is culture-sensitive, as Esperento57 points out.
This surprising behavior is discussed in this GitHub issue.
Provided the [datetime] sections are ascending,
it should be sufficient to split on them with a RegEx and get the last one
((Get-Content .\test.txt -Raw) -split "\d+/\d+/\d{4} \d+:\d+:\d+ [AP]M`r?`n")[-1]
Output based on your sample string stored in file test.txt
This would be second message
Same type of stuff
But its a different message
you can split it by timestamp pattern like this:
$arr = $str -split "[0-9]{1,2}/[0-9]{1,2}/[0-9]{1,4} [0-9]{1,2}:[0-9]{1,2}:[0-9]{1,2} [AaPp]M\n"
To my knowledge you can't use any of the static String methods like Split() for this. I tried to find a regular expression that would handle the entire thing, but wasn't able to come up with anything that would quite break it up properly.
So, you'll need to go line by line, testing to see if it that line is a date, then concatenate the lines in between like the following:
$fileContent = Get-Content "inputFile.txt"
$messages = #()
$currentMessage = [string]::Empty
foreach($line in $fileContent)
{
if ([Regex]::IsMatch($line, "\d{1,2}/\d{1,2}/\d{4} \d{1,2}:\d{2}:\d{2} (A|P)M"))
{
# The current line is a date, the current message is complete
# Add the current message to the output, and clear out the old message
# from your temporary storage variable $currentMessage
if (-not [string]::IsNullOrEmpty($currentMessage))
{
$messages += $currentMessage
$currentMessage = [string]::Empty
}
}
else
{
# Add this line to the message you're building.
# Include a new line character, as it was stripped out with Get-Content
$currentMessage += "$line`n"
}
}
# Add the last message to the output
$messages += $currentMessage
# Do something with the message
Write-Output $messages
As the key to all of this is recognizing that a given line is a date and therefore the start of a message, let's look a bit more at the regex. "\d" will match any decimal character 0-9, and the curly braces immediately following indicate the number of decimal characters that need to match. So, "\d{1,2}" means "look for one or two decimal characters" or in this case the month of the year. We then look for a "/", 1 or 2 more decimal characters - "\d{1,2}", another "/" and then exactly 4 decimal characters - "\d{4}". The time is more of the same, with ":" in between the decimal characters instead of "/". At the end, there will either be "AM" or "PM" so we look for either an "A" or a "P" followed by an "M", which as a regular expression is "(A|P)M".
Combine all of that, and you get "\d{1,2}/\d{1,2}/\d{4} \d{1,2}:\d{2}:\d{2} (A|P)M" to determine if you have a date on that line. I believe it would also be possible to use[DateTime]::Parse() to determine if the line is a date, but then you wouldn't get to have fun with Regex's and would need a try-catch. For more info on Regex's in Powershell (which are just the .NET regex) see .NET Regex Quick Reference
I got data like this:
3LLO24MACT01 24MOB_6012010051700000020100510105010 123456
It contains different values for different columns when I import it.
Every column is fixed width:
Col#1 is the ID and just 1 long. Meaning it is "3" here.
Col#2 is 3 in length and here "LLO".
Col#3 is 9 in length and "24MACT01 " (notice that the missing ones gets filled up by blanks).
This goes on for 15 columns or so...
Is there a method to quickly cut it into different elements based on sequence length? I couldn't find any.
This can be done with RegEx matching, and creating an array of custom objects. Something like this:
$AllRecords = Get-Content C:\Path\To\File.txt | Where{$_ -match "^(.)(.{3})(.{9})"} | ForEach{
[PSCustomObject]#{
'Col1' = $Matches[1]
'Col2' = $Matches[2]
'Col3' = $Matches[3]
}
}
That will take each line, match by how many characters are specified, and then create an object based off those matches. It collects all objects in an array and could be exported to CSV or whatever. The 'Col1', 'Col2' etc are just generic column headers I suggested due to a lack of better information, and could be anything you wanted.
Edit: Thank you iCodez for showing me, perhaps inadvertantly, that you can specify a language for your code samples!
[Regex]::Matches will do this rather easily. All you need to do is specify a Regex pattern that has . followed by the number of characters you want in curly braces. For example, to match a column of three characters, you would write .{3}. You then do this for all 15 columns.
To demonstrate, I will use a string that contains the first three columns of your example data (since I know their sizes):
PS > $data = '3LLO24MACT01 '
PS > $pattern = '(.{1})(.{3})(.{9})'
PS > ([Regex]::Matches($data, $pattern).Groups).Value
3LLO24MACT01
3
LLO
24MACT01
PS >
Note that the first value outputted will be the text matched be all of the capture groups. If you do not need this, you can remove it with slicing:
$columns = ([Regex]::Matches($data, $pattern).Groups).Value
$columns = $columns[1..$columns.Length]
New-PSObjectFromMatches is a helper function for creating PS Objects from regex matches.
The -Debug option can help with the process of writing the regex.