Powershell string manipulation and replace

Question

I have a powershell string which can contain multiple email address, for example below is a exmaple that contains two email ids. In that i have two scenarios.

1) Scenario One where the @gmail.com is consistent
strEmail=john.roger@gmail.com,smith.david@gmail.com

2) Secnario second: where the @mail.com could be different
strEmail2 = john.roger@gmail.com,smith.david@outlook.com

I need to get rid of anything after @ including it.

So for result for 
scenario (1) will be: john.roger,smith.david  
Scenario (2) will be: john.roger,smith.david

SO for Scenarion(1) i can use replace with "hardcoded" value of "@gmail.com", How about second secnario.

I am looking for some solution which will work for both scenarion... like something in Regex or any other way i don't know.

Answer 1

Splitting and joining would return the names on one line

Following

$strEmail = "john.roger@gmail.com,smith.david@outlook.com"
($strEmail -split "," | % {($_ -split "@")[0]}) -join ","

returns

john.roger,smith.david

Breakdown

$strEmail -split ","      returns an array of two elements
                            [0] john.roger@gmail.com
                            [1] smith.david@outlook.com

% {($_ -split "@")[0]}    loops over the array
                          and splits each item into an array of two elements
                            [0] john.roger
                            [1] gmail.com

                            [0] smith.david
                            [1] outlook.com
                          and returns the first element [0] from each array

- join ","                joins each returned item into a new string

Answer 2

Both of these should work.

This will print each name on a new line:

$strEmail = "john.roger@gmail.com,smith.david@outlook.com"

$strEmail = $strEmail.Split(',') | Foreach {
   $_.Substring(0, $_.IndexOf('@'))
}

$strEmail

This will give you the same output as you outlined above:

$strEmail = "john.roger@gmail.com,smith.david@outlook.com"
$strEmailFinal = ""

$strEmail = $strEmail.Split(',') | Foreach {
   $n = $_.Substring(0, $_.IndexOf('@'))
   $strEmailFinal = $strEmailFinal + $n + ","
}

$strEmailFinal.TrimEnd(',')

Answer 3

Another approach... Well, if you like RegEx of course

Clear-Host 
$SomeEmailAddresses = @'
1) Scenario One where the @gmail.com is consistent
strEmail=john.roger@gmail.com,smith.david@gmail.com

2) Secnario second: where the @mail.com could be different
strEmail2 = john.roger@gmail.com,smith.david@outlook.com
'@

((((Select-String -InputObject $SomeEmailAddresses `
-Pattern '\w+@\w+\.\w+|\w+\.\w+@\w+\.\w+|\w+\.\w+@\w+\.\w+\.\w+' `
-AllMatches).Matches).Value) -replace '@.*') -join ','

Results

john.roger,smith.david,john.roger,smith.david

Just comment out or delete the -join for one per line