--deleted earlier text - I asked the wrong question!
ahem....
What I have is $var = "\\unknowntext1\alwaysSame\unknowntext2"
I need to keep only "\\unknowntext1"
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3 Answers
Try regular expressions:
$foo = 'something_of_unknown' -replace 'something.*','something'
Or if you know only partially the 'something', then e.g.
'something_of_unknown' -replace '(some[^_]*).*','$1'
'some_of_unknown' -replace '(some[^_]*).*','$1'
'somewhatever_of_unknown' -replace '(some[^_]*).*','$1'
The $1 is reference to group in parenthesis (the (some[^_]*) part).
Edit (after changed question):
If you use regex, then special characters need to be escaped:
"\\unknowntext1\alwaysSame\unknowntext2" -replace '\\\\unknowntext1.*', '\\unknowntext1'
or (another regex magic) use lookbehind like this:
"\\unknowntext1\alwaysSame\unknowntext2" -replace '(?<=\\\\unknowntext1).*', ''
(which is: take anything (.*), but there must be \\unknowntext1 before it ('(?<=\\\\unknowntext1)) and replace it with empty string.
Edit (last)
If you know that there is something known in the middle (the alwaysSame), this might help:
"\\unknowntext1\alwaysSame\unknowntext2" -replace '(.*?)\\alwaysSame.*', '$1'
1 Comment
stej
Edited the answer, but as I see now, I have to edit it once again ;)
What I have is $var = "\unknowntext1\alwaysSame\unknowntext2"
I need to keep only "\unknowntext1"
Not sure this requires a regular expression. Assuming alwaysSame is literally always the same, as the discussion around stej's answer suggests, it seems by far the most straightforward way to accomplish this would be:
$var.substring(0, $var.indexOf("\alwaysSame"));
2 Comments
ruffin
How does that not answer the question? If you have
$var = "\\unknowntext1\alwaysSame\unknowntext2" and you run $var.substring(0, $var.indexOf("\alwaysSame"));, you get \\unknowntext1, QED. Was just surprised the other answers were nontrivially more convoluted.ruffin
I notice neither of you (Hashem & Lucas) have a
powershell tag in your profile. Lines of Powershell code always* emit their results to the "pipeline", if that's throwing you. That statement in my answer will "return" the value the OP requested; every PowerShell line of code is sort of like an implicit function which can be chained to another subsequent command. I can see how that might have confused you. I've also edited the answer to make my intent clearer to non-PS users.function Remove-TextAfter {
param (
[Parameter(Mandatory=$true)]
$string,
[Parameter(Mandatory=$true)]
$value,
[Switch]$Insensitive
)
$comparison = [System.StringComparison]"Ordinal"
if($Insensitive) {
$comparison = [System.StringComparison]"OrdinalIgnoreCase"
}
$position = $string.IndexOf($value, $comparison)
if($position -ge 0) {
$string.Substring(0, $position + $value.Length)
}
}
Remove-TextAfter "something_of_unknown" "SoMeThInG" -Insensitive
1 Comment
ruffin
Thanks for the
System.StringComparison format. ;^)