How to use a string value in foreach?
The following works.
$printString='$_.name+","+$_.name'
Get-ChildItem|foreach {$_.name+','+$_.name}
But the following doesn't work
Get-ChildItem|foreach {$printString}
But I need it to work: because I have a task to print each column in a table, I can use table dictionary to get all the columns, so all are dynamic, and then when I try to print the result, I also use a string like above to print the result. Any solution
There are several solutions. Some of them that came on my mid are:
$printString='$($_.name),$($_.name)'
Get-ChildItem | % { $ExecutionContext.InvokeCommand.ExpandString($printString) }
$formatString='{0},{0}'
Get-ChildItem | % { $formatString -f $_.Name }
$s = {param($file) $file.Name + "," + $file.Name }
Get-ChildItem | % { & $s $_ }
The first one expands string and that's probably what you wanted. Note that composed variables have to be enclosed in $(..). The second just formats some input. The third uses scriptblock there you can create any string you want (the most powerfull)
One possible solution:
$printString={$_.name+","+$_.name}
Get-ChildItem |foreach {.$printString}
Another possible solution:
$printString='$_.name+","+$_.name'
Get-ChildItem|foreach { Invoke-Expression $printString }
Interesting possibility:
dir | select #{Name='Name'; Expression={$_.Name, $_.Name}}
Related
$testing = #("a.txt", "b.txt")
$testing | Select-String???
I would like the output to only contain a, b.
My real example is:
$PackageNames = Get-ChildItem ("$DestinationPath\$ProjectName" + "_2105\" + $ProjectName) -Filter *.dtsx | Select-Object name -ExpandProperty name;
I need to use the content in this variable but without the extensions.
Working with files is easier, if you use FileInfo class' BaseName property. Like so,
$PackageNames = Get-ChildItem ("$DestinationPath\$ProjectName" + "_2105\" + $ProjectName) -Filter *.dtsx
# Process the results
foreach($pkg in $PackageNames) {
$pkg.BaseName # Just prints the file name without extension
}
Try this:
$a|%{($_.tostring().split("."))[0]}
Iterate over the array, split by a dot and and get the first item.
I have an application that generates 100's of text log files which are like
DaemonReruns=2|
Phase=|
Log=false|
DS=LOG_4|
Schema=LOLYY|
DBMS=mssql|
Host=abc.XYz.com|
IDs=xxxxx,xxxx
I need to select Host from these
I tried
GC C:\log_5.txt |
Select-String -Pattern 'Host=\"([^\"]*)\"'
Gives no results, any help ?
There aren't any quotes in your example input. Try this regex:
get-content C:\log_5.txt | foreach {
if ($_ -match 'Host=([^|]+)') {
$Matches.1
}
}
Note: This actually returns the host names, not just the line.
marsze's helpful answer fixes the problem with your regex and uses a ForEach-Object (foreach) call to extract and return matches via the -match operator and the automatic $Matches variable.
Here's a concise (and better-performing) alternative using the switch statement:
PS> switch -Regex -File C:\log_5.txt { 'Host=([^|]+)' { $Matches[1] } }
abc.XYz.com
Note that -File doesn't accept wildcard-based paths, however, so in order to process multiple file, you'll have to loop over them via Get-ChildItem or Convert-Path.
((Get-Content -Path .\log_5.txt) -match 'Host=') -replace 'Host=',''
returns all the lines starting with Host=
Just for fun ... the super-fast solution:
$regex = [Regex]::new('Host=([^|]+)', 'Compiled, IgnoreCase, CultureInvariant')
& {foreach ($line in [IO.File]::ReadLines("C:\log_5.txt")) {
$m = $regex.Match($line)
if ($m.Success) {
$m.Groups[1].Value
}
}}
If your logs are huge, it could be worth the overhead of Add-Type, and the rest would be much faster:
Add-Type '
using System.IO;
using System.Collections.Generic;
using System.Text.RegularExpressions;
namespace PowerShell
{
public class Tools
{
static Regex regex = new Regex(#"Host=([^|]+)", RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
public static IEnumerable<string> GetHosts(string path)
{
foreach(var line in File.ReadLines(path))
{
var matches = regex.Match(line);
if (matches.Success)
{
yield return matches.Groups[1].Value;
}
}
}
}
}'
# call this for each log file (very fast)
[PowerShell.Tools]::GetHosts("C:\log_5.txt")
Other answers have the regex side covered well enough. Whenever I see little logs like this I always think about ConvertFrom-StringData which
converts a string that contains one or more key and value pairs into a hash table.
From: help ConvertFrom-StringData
In its basic form we just do something like this:
$pairs = Get-Content -Raw -File $pathtofile | ConvertFrom-StringData
[pscustomobject]$pairs
Which would give you a PowerShell object that you can interact with easily!
DS : LOG_4|
Schema : LOLYY|
IDs : xxxxx,xxxx
Log : false|
DBMS : mssql|
Host : abc.XYz.com|
Phase : |
DaemonReruns : 2|
Doubtful that you need the trailing pipes. You can remove those with some regex or simpler string methods.
[pscustomobject](Get-Content -File $pathToFile | ForEach-Object{$_.trimend("|")} | Out-string | ConvertFrom-StringData)
[pscustomobject]((Get-Content -Raw -File $pathToFile) -replace "(?m)\|$" | ConvertFrom-StringData)
In any case this gives you more options as to how you need to deal with your data.
I want to print the word exist in a text file and print "match" and "not match". My 1st text file is: xxaavv6J, my 2nd file is 6J6SCa.yB.
If it is match, it return like this:
Match found:
Match found:
Match found:
Match found:
Match found:
Match found: 6J
Match found:
Match found:
Match found:
My expectation is just print match and not match.
$X = Get-Content "C:\Users\2.txt"
$Data = Get-Content "C:\Users\d.txt"
$Split = $Data -split '(..)'
$Y = $X.Substring(0, 6)
$Z = $Y -split '(..)'
foreach ($i in $Z) {
foreach ($j in $Split) {
if ($i -like $j) {
Write-Host ("Match found: {0}" -f $i, $j)
}
}
}
The operation -split '(..)' does not produce the result you think it does. If you take a look at the output of the following command you'll see that you're getting a lot of empty results:
PS C:\> 'xxaavv6J' -split '(..)' | % { "-$_-" }
--
-xx-
--
-aa-
--
-vv-
--
-6J-
--
Those empty values are the additional matches you're getting from $i -like $j.
I'm not quite sure why -split '(..)' gives you any non-empty values in the first place, because I would have expected it to produce 5 empty strings for an input string "xxaavv6J". Apparently it has to do with the grouping parentheses, since -split '..' (without the grouping parentheses) actually does behave as expected. Looks like with the capturing group the captured matches are returned on top of the results of the split operation.
Anyway, to get the behavior you want replace
... -split '(..)'
with
... |
Select-String '..' -AllMatches |
Select-Object -Expand Matches |
Select-Object -Expand Value
You can also replace the nested loop with something like this:
foreach ($i in $Z) {
if (if $Split -contains $i) {
Write-Host "Match found: ${i}"
}
}
A slightly different approach using regex '.Match()' should also do it.
I have added a lot of explaining comments for you:
$Test = Get-Content "C:\Users\2.txt" -Raw # Read as single string. Contains "xxaavv6J"
$Data = (Get-Content "C:\Users\d.txt") -join '' # Read as array and join the lines with an empty string.
# This will remove Newlines. Contains "6J6SCa.yB"
# Split the data and make sure every substring has two characters
# In each substring, the regex special characters need to be Escaped.
# When this is done, we join the substrings together using the pipe symbol.
$Data = ($Data -split '(.{2})' | # split on every two characters
Where-Object { $_.Length -eq 2 } | # don't care about any left over character
ForEach-Object { [Regex]::Escape($_) } ) -join '|' # join with the '|' which is an OR in regular expression
# $Data is now a string to use with regular expression: "6J|6S|Ca|\.y"
# Using '.Match()' works Case-Sensitive. To have it compare Case-Insensitive, we do this:
$Data = '(?i)' + $Data
# See if we can find one or more matches
$regex = [regex]$Data
$match = $regex.Match($Test)
# If we have found at least one match:
if ($match.Groups.Count) {
while ($match.Success) {
# matched text: $match.Value
# match start: $match.Index
# match length: $match.Length
Write-Host ("Match found: {0}" -f $match.Value)
$match = $match.NextMatch()
}
}
else {
Write-Host "Not Found"
}
Result:
Match found: 6J
Further to the excellent Ansgar Wiechers' answer: if you are running (above) Windows PowerShell 4.0 then you could apply the .Where() method described in Kirk Munro's exhaustive article ForEach and Where magic methods:
With the release of Windows PowerShell 4.0, two new “magic” methods
were introduced for collection types that provide a new syntax for
accessing ForEach and Where capabilities in Windows PowerShell.
These methods are aptly named ForEach and Where. I call
these methods “magic” because they are quite magical in how they work
in PowerShell. They don’t show up in Get-Member output, even if you
apply -Force and request -MemberType All. If you roll up your
sleeves and dig in with reflection, you can find them; however, it
requires a broad search because they are private extension methods
implemented on a private class. Yet even though they are not
discoverable without peeking under the covers, they are there when you
need them, they are faster than their older counterparts, and they
include functionality that was not available in their older
counterparts, hence the “magic” feeling they leave you with when you
use them in PowerShell. Unfortunately, these methods remain
undocumented even today, almost a year since they were publicly
released, so many people don’t realize the power that is available in
these methods.
…
The Where method
Where is a method that allows you to filter a collection of objects.
This is very much like the Where-Object cmdlet, but the Where
method is also like Select-Object and Group-Object as well,
includes several additional features that the Where-Object cmdlet
does not natively support by itself. This method provides faster
performance than Where-Object in a simple, elegant command. Like
the ForEach method, any objects that are output by this method are
returned in a generic collection of type
System.Collections.ObjectModel.Collection1[psobject].
There is only one version of this method, which can be described as
follows:
Where(scriptblock expression[, WhereOperatorSelectionMode mode[, int numberToReturn]])
As indicated by the square brackets, the expression script block is
required and the mode enumeration and the numberToReturn integer
argument are optional, so you can invoke this method using 1, 2, or 3
arguments. If you want to use a particular argument, you must provide
all arguments to the left of that argument (i.e. if you want to
provide a value for numberToReturn, you must provide values for
mode and expression as well).
Applied to your case (using the simplest variant Where(scriptblock expression) of the .Where() method):
$X = '6J6SCa.yB' # Get-Content "C:\Users\2.txt"
$Data = 'xxaavv6J' # Get-Content "C:\Users\d.txt"
$Split = ($Data -split '(..)').Where({$_ -ne ''})
$Y = $X.Substring(0, 6)
$Z = ($Y -split '(..)').Where{$_ -ne ''} # without parentheses
For instance, Ansgar's example changes as follows:
PS > ('xxaavv6J' -split '(..)').Where{$_ -ne ''} | % { "-$_-" }
-xx-
-aa-
-vv-
-6J-
In Powershell, I have a hash table that contains data similar to this -
Name Value
---- -----
1-update.bat 1
2-update.bat 2
3-update.bat 3
3.1-update.bat 3.1
4-update.bat 4
I also have an variable that contians a number, for example 3
What I would like to do is loop through the array and remove any entry where the value is less than or equal to 3
I'm thinking that this will be easy, especially as the docs say that has tables contain a .remove method. However, the code I have below fails, yeilding this error -
Exception calling "Remove" with "1" argument(s): "Collection was of a
fixed size."
Here is the code that I used -
$versions = #{}
$updateFiles | ForEach-Object {
$versions.Add($_.name, [decimal]($_.name -split '-')[0])
}
[decimal]$lastUpdate = Get-Content $directory\$updatesFile
$versions | ForEach-Object {
if ( $_.Value -le $lastUpdate ) {
$versions.Remove($version.Name)
}
}
I first tried to loop $versions in a different manner, trying both the foreach and for approaches, but both failed in the same manner.
I also tried to create a temporary array to hold the name of the versions to remove, and then looping that array to remove them, but that also failed.
Next I hit Google, and while I can find several similar questions, none that answer my specific question. Mostly they suggest using a list (New-Object System.Collections.Generic.List[System.Object]), whcih from what I can tell is of no help to me here.
Is anyone able to suggest a fix?
Here you go, you can use .Remove(), you just need a clone of the hashtable so that it will let you remove items as you enumerate.
[hashtable]$ht = #{ '1-update.bat'=1;'2-update.bat'=2;'3-update.bat'=3;'3.1-update.bat'=3.1; '4-update.bat'=4 }
#Clone so that we can remove items as we're enumerating
$ht2 = $ht.Clone()
foreach($k in $ht.GetEnumerator()){
if([decimal]$k.Value -le 3){
#notice, deleting from clone, then return clone at the end
$ht2.Remove($k.Key)
}
}
$ht2
Notice I've cast the original variable too so that it's explicitly a hash table, may not be required, but I like to do it to at least keep things clear.
It looks like you just confused ForEach-Object with foreach but only halfway (maybe it was foreach before and you converted it).
You can't send a [hashtable] directly to ForEach-Object; the $_ in that case will just refer to the single [hashtable] you sent in. You can do:
foreach ($version in $versions.GetEnumerator()) {
$version.Name
$version.Value
}
or you can do something like this:
$versions.Keys | ForEach-Object {
$_ # the name/key
$versions[$_] # the value
$versions.$_ # also the value
}
$ht.Keys # list all keys
$ht[$_] # take an element of hastable
$ht.Remove($_) # remove an element of hastable by his key
what you want:
$ht.Keys | ? { $ht[$_] -le 3 } | %{$ht.Remove($_) }
You need to create a temporary array to hold the name/key of the versions to remove, and then looping that array to remove them from hash table:
$versionKeysToRemove = $versions.Keys | Where-Object { $versions[$_] -le $lastUpdate }
$versionKeysToRemove | ForEach-Object { $versions.Remove($_) }
Or shorter:
($versions.Keys | ? { $versions[$_] -le $lastUpdate }) | % { $versions.Remove($_) }
Please note the parentheses.
I was wondering if this was possible. I am trying to make a script we will refer to as a master script. This script queries a DB to get a list of servers we will call $svrs. Simple stuff.
The thing I don't know how to do or if it is possible is to run a series of subscripts from the master script using the $srvrs.Name variable as a parameter on those scripts.
$svrs = "get list sql stuff"
$scrpath = 'D:\test'
$scripts = Get-ChildItem $scrpath
$scripts.Name | ForEach-Object {
Invoke-Expression $_ {I have no idea how to get server name variable here}
}
Based on the comments, you do need a nested loop which won't be too complicated.
$Scripts | Select-object Name | % {$curScript = $_
$Servers | % {.\$_ $CurScript}
}
I ended up resolving this myself with #JNK 's assistance...
Here is how I got the result I needed.
$allServers | ForEach-Object {
$currentServer = $_
$scripts.Name | ForEach-Object {
Invoke-Expression ".\$_ $currentServer"
}
}