Error with Substring() - powershell

$fileName = "Name of TheFolder_NE_ED"
$lengthFileName = $fileName.length
$shortenLengthFileName = $lengthFileName - 5
Write-Host("Name of TheFolder_NE_ED").Substring($shortenLengthFileName,$lengthFileName)
$x = $host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
I am having a problem with SubString() function, it errors with:
I tried printing out values of my variables but they seemed fine.

In PowerShell, substring works in a slightly different way.
With your existing code you could try this:
$fileName = "Name of TheFolder_NE_ED"
$lengthFileName = $fileName.length
$shortenLengthFileName = $lengthFileName - 5
Write-Host("Name of TheFolder_NE_ED").Substring($shortenLengthFileName)
Explanation:
The first parameter inside Substring should be the starting index of the character(in this case 18). Now from that letter it will start counting till the character (which you have to pass as a second parameter). Else it will by default go to the end of the string.
So, if you want to pass 2 parameters and do that, then change it to:
Write-Host("Name of TheFolder_NE_ED").Substring($shortenLengthFileName,5)
For further reference, follow Substring Use
Hope it helps.

Related

Create an incrementing variable from 2 variables in PowerShell

OK, First I consider myself a newbie and have much to learn about PowerShell and this is my first post ever.
I am trying to loop through some data and put it into a custom object and put them into separate arrays for later use. The issue is that I want to create a variable representing $week_data1 by using a counter $i so I can reduce the amount of code required. I do have a concatenated variable being written out: write-host '$week++ ='$week$i But I think it is being represented as a string?
How can I get $week_data$i to represent the array to insert the data?
Input data. Each week ends on Saturday.
$week1=#('2021-05-01')
$week2=#('2021-05-02', '2021-05-03', '2021-05-04', '2021-05-05', '2021-05-06', '2021-05-07', '2021-05-08')
$week3=#('2021-05-09', '2021-05-10', '2021-05-11', '2021-05-12', '2021-05-13', '2021-05-14', '2021-05-15')
$week4=#('2021-05-16', '2021-05-17', '2021-05-18', '2021-05-19', '2021-05-20', '2021-05-21', '2021-05-22')
$week5=#('2021-05-23', '2021-05-24', '2021-05-25', '2021-05-26', '2021-05-27', '2021-05-28', '2021-05-29')
$week6=#('2021-05-30', '2021-05-31')
$month =#($week1, $week2, $week3, $week4, $week5, $week6)
Create the output structures to be populated.
$week_data1=#()
$week_data2=#()
$week_data3=#()
$week_data4=#()
$week_data5=#()
$week_data6=#()
$month_data =#($week_data1, $week_data2, $week_data3, $week_data4, $week_data5, $week_data6)
Loop through the array and count the week number that is being processed.
$i = 0
foreach($week in $month)
{ $i++
$n=0
Here I can write out a Variable and it concatenates properly.
**write-host '$week++ ='$week$i**
foreach($day in $week)
{$n++
write-host '$day ='$day
Pull in data from a .csv file to populate the custom object.
foreach($line in $csv)
{
if($line -match $day)
Match the line in the CSV file that has the correct Date in it. One line in the file per date in the month.
{ #write-host '$line.Day = ' $line.Day
# custom object to be used later
$date_data = [PSCustomObject] #{
week_numb = $i
date = $line.Day
attempts = $line.Attempts
connects = $line.Connects
}
I have tried different syntax versions but it does not work here? I want to put the custom object data into the new array for the week being processed.
#write-host '$week_data[$i]='$week_data[$i]
$week_data$i += $date_data # Add data from csv file into a
#$week_data[$i] += $date_data
}
}
}
}
Issue using $week_data$i as a variable I get an error:
At line:38 char:17
$week_data$i += $date_data # Add data from csv file into a
~~
Unexpected token '$i' in expression or statement.
+ CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : UnexpectedToken
You're looking for variable indirection, i.e. the ability to refer to a variable indirectly, by a name stored in another variable or returned from an expression.
Note, however, that there are usually superior alternatives, such as using arrays or hashtables as multi-value containers - see this answer for an example.
If you do need to use variable indirection, use Get-Variable and Set-Variable:
$week_data1 = 'foo', 'bar'
$i = 1
# Same as: $week_data1
# Note that "$" must NOT be specified as part of the name.
Get-Variable "week_data$i" -ValueOnly
# Same as: $week_data1 = 'baz', 'quux'
Set-Variable "week_data$i" baz, quux
# Updating an existing value requires nesting the two calls:
# Same as: $week_data1 += 'quuz'
Set-Variable "week_data$i" ((Get-Variable "week_data$i" -ValueOnly) + 'quuz')
As an aside: "extending" an array with += is convenient, but inefficient: a new array must be created behind the scenes every time - see this answer.
Similarly, calling cmdlets to set and get variables performs poorly compared to direct assignments and variable references.
See this answer for applying the indirection technique analogously to environment variables, using Get-Content / Set-Content and the Env: drive.
As for what you tried:
$week_data$i = ... is an assignment expression, which is interpreted as directly juxtaposing two variables, $week_data and $i, which causes the syntax error you saw.
By contrast, something like Write-Output $week_data$i is a command, and while $week_data$i is also interpreted as two variable references, as a command argument it is syntactically valid, and would simply pass the (stringified) concatenation of the two variable values; in other words: $week_data$i acts as if it were double-quoted, i.e. an expandable string, and the command is therefore equivalent to Write-Output "$week_data$i"
Unrelated to the answer, but likely helpful for you, I have a function that will determine what week in a month a given date is.
Function Get-Week{
[cmdletbinding()]
param([parameter(ValueFromPipeline)][string[]]$Date)
process{
ForEach($Day in $Date){
$DTDay=[datetime]$Day
$Buffer = ([datetime]("{0}-01-{1}" -f $DTDay.Month,$DTDay.Year)).dayofweek.value__ -1
[math]::Truncate(($DTDay.Day+$Buffer)/7)+1
}
}
}
So you feed that a string that can be converted to a date like:
'5-13-2021' | Get-Week
or
Get-Week '5-13-2021'
and you get back a number indicating what week (ending on Saturday) of the month that day falls in.

Loop through multiple array in powershell

I have 2 arrays here one contains the servername and other contains the IP.
I need to loop through them and create a key value pair like below for each server
server1:ip1
server2:ip2
I have written below code, but the problem is if i debug the code using F11, it is working fine, but i don't it gives some error which is different every time.
so feeling like it is not that reliable piece to continue.
$NewDNSEntryName = $DNSEntryName.Split(",")
$DNSIPs = $DNSIP.Split(",")
if($DNSEntryName -match "," -or $DNSIP -match ",")
{
0..($NewDNSEntryName.Count - 1) | ForEach-Object {
$fullName=""
$fullName += #("$($NewDNSEntryName[$_]):$($DNSIPs[$_])")
This is the line where i am facing trouble
0..($NewDNSEntryName.Count - 1) | ForEach-Object
Please let me know why this code is behaving like this else any alternate idea is appreciated
Assuming each item in each list corresponds with each other exactly, you can use a for loop and loop through the array indexes.
$NewDNSEntryName = $DNSEntryName.Split(",")
$DNSIPs = $DNSIP.Split(",")
for ($i = 0; $i -lt $DNSIPs.count; $i++) {
"{0}:{1}" -f $NewDNSEntryName[$i],$DNSIPs[$i]
}
For the code above to work, $DNSEntryName and $DNSIP must be single strings with commas between names and IPs. If $DNSEntryName and $DNSIP are already lists or arrays, something else will need to be done.
In your attempt, technically, your logic should work given everything written above is true. However, $fullName is emptied at every single iteration, which may produce undesirable results.

Store everything after second `/`

I have this string in a Powershell Variable:
$buildParametersSourceBranch = refs/heads/pb/31333-test-branch/name
When I run $buildParametersSourceBranch.split('/')[2]
The result is pb. I assumed the split would show everything after the second / but it seems to only show the value between the second / and third /.
String.Split() doesn't "know" that you're only interested in a particular subset of the result and only want the string split in 2 places.
Use the -split operator and specify a max number of resulting substrings:
$rest = ($buildParametersSourceBranch -split '/',3)[2]
# or
$null,$null,$rest = $buildParametersSourceBranch -split '/',3

PowerShell array/index/variable

The below code is checking in a dropdownbox, which item has been selected and then is searched in several arrays and as soon found, the loop is broken through break and I receive the correct information in "`$$($array.name)".
$search = $CreateNewUserFormDropDownBoxLocation.SelectedItem.Split('-')[$($CreateNewUserFormDropDownBoxLocation.SelectedItem.Split('-').Count - 1)].Trim() + '*'
$AllLocations = (Get-Variable -Include USPennsylvaniaAve, USSixthStreet, USRodeoDrive, USOneMicrosoftWay,`
USNorthTantauAvenue, USMarketStreet, USMainStreet, USEmilyDrive,`
USCalle8, USBroadway, US18thStreetNW, UKOxfordStreet, UKDowningStreet,`
UKBondStreet, FRRuedeRivoli, FRChampsElysees, CHBahnhofstrasse,`
CA17thAvenue) | ? {$_.value -is [array]}
foreach ($Array in $AllLocations) {
if ($array.value -like $search) {
break
}
}
$test = "`$$($array.name)"
The issue is the variable $test does contain the correct array and I am interested, to work with the index (I hope I say that correctly).
For example, after the code ran and I enter $test, the result is for example $USMarketStreet, which is one of my arrays.
If I try to get the first index by typing $test[0] I do not get the expected content from the array, it gives me $.
If I enter $test[0..4] I get:
$
U
S
M
a
My intention was, to get the first key out of the array but instead of that, I am getting the first character out of the array name.
Is there a trick, how I can get to it? I also tried to play around with $array and $array.value but no success.

Substring is getting too less data

I want to grab lots of text content from a .sql file between a --Start and --End comment.
Whatever I do somehow I don`t get the substring method correctly to grab only the text within the --Start and --End comment:
text.sql
This text I want not
--Start
this text I want here
--End
This text I want not
This is what I tried:
$insertStartComment = "--Start"
$insertEndComment = "--End"
$content = [IO.File]::ReadAllText("C:\temp\test.sql")
$insertStartPosition = $content.IndexOf($insertStartComment) + $insertStartComment.Length
$insertEndPosition = $content.IndexOf($insertEndComment)
$content1 = $content.Substring($insertStartPosition, $content1.Length - $insertEndPosition)
$content = $content1.Substring(0,$content1.Length - $insertEndPosition)
It would be nice if someone could help me out find my error :-)
There's an attempt to use uninitialized variable in the code:
$content1 = $content.Substring($insertStartPosition, $content1.Length - $insertEndPosition)
The variable $content1 isn't initialized yet, thus the substring call goes haywire. When you run the code again, the variable is set - and results are even more weird.
Use Powershell's Set-StrictMode to enable warnings about uninitialized variables.
It's not the substring approach you are looking for, but I figured that I would toss out a RegEx solution. This will find the text between the --Start and --End on a text file. In this case, I am grouping the matched text with a named capture called LineYouWant and display the matches that it finds. This also works if you have multiple instances of --Start--End blocks in a single file.
$Text = [IO.File]::ReadAllText("C:\users\proxb\desktop\SQL.txt")
[regex]::Matches($Text,'.*--Start\s+(?<LineYouWant>.*)\s+--End.*') | ForEach {
$_.Groups['LineYouWant'].Value
}