I want to get "localhost" (or whatever text) inside this string:
XML-Execute-Result: <host>localhost</host>
I want a general method, like a way to reuse an expression value
(like with sed in linux)
sed 's/*[0-9]$/\$&/'
Thank you very much for any reply
$text = "XML-Execute-Result: <host>localhost</host>"
if ($text -match "\<host\>(?<host>.*?)\</host\>")
{
$myhost = $matches.host
}
PS> if ($text -match "<host>(.*?)</host>") {$matches[1]}
localhost
Related
For example,
$test = "abc";
$test =~ s/b//g;
normally test will be ac. How do I manipulate the string "abc" so that it will go through this test and still return abc.
I am trying to do a command injection so I can't change $test =~ s/b//g; but can change the input.
Hopefully this makes sense.
You want to use the /r modifier. it's a new'ish feature so older versions will not run it
$test = "abc";
my $str= $test =~ s/b//gr;
http://perldoc.perl.org/perlre.html#Modifiers
There is no string you can pass to s/b//g that will result in a string that contains a b.
However, if you have access to $test and not just it's value, you could set its pos such that the substitution operator won't find anything.
$ perl -e'
my $test = "abc";
pos($test) = length($test);
$test =~ s/b//g;
CORE::say($test);
'
ac
My string is:
$dst = "Folder_1\SubFolder_2\3\4\5"
My goal is to have:
$dst_OK = "SubFolder_2\3\4\5"
I tried use split function like this:
$dst_OK = $dst.split("\")[0]
but the result is Folder_1 only.
You could use the following regex to remove the left side of the string:
$dst_OK = $dst -replace '^.*?\\'
However, since it looks like you are dealing with a path, you may consider to using builtin function within the System.IO.Path namespace.
You can do it with this snippet:
$first, $rest = "Folder_1\SubFolder_2\3\4\5" -split '\\'
$rest = $rest -join '\'
Other solution :
($dst -split "\\", 2)[1]
Solution 2
$dst.Substring($dst.IndexOf('\')+1)
The shell script will be passed a string of arguments. The position of the key/value I am looking to parse out may change over time, i.e. it may come before or after another key at any time so parsing between two keys wouldn't be an option.
I am looking to parse the domain key out of a string like this:
maxpark 0 maxsub n domain sample.foo maxlst n max_defer_fail_percentage user oli force no_cache_update 0 maxpop n maxaddon 0 locale en contactemail
The key would be "domain" the value would be "sample.foo". The domain key could have more than one '.' in it so I would need to grab the entire domain key.
I am not the best with regular expressions but I imagine using 'sed' is what I'm going to need to do.
I am accessing this full string using $*, if I could simply reference the key by accessing $DOMAIN that would be great, but since my only option is to access based on position, $3, and the position could change, that isn't an option
Solved the problem using PERL.
#!/usr/bin/perl -w
use strict;
my %OPTS = #ARGV;
open(FILE, "</var/named/$OPTS{'domain'}.db") || die "File not found";
my #lines = <FILE>;
close(FILE);
my #newlines;
foreach(#lines) {
$_ =~ s/$LOCAL_IP/$PUBLIC_IP/g;
push(#newlines,$_);
}
open(FILE, ">/var/named/$OPTS{'domain'}.db") || die "File not found";
print FILE #newlines;
close(FILE);
If you do have perl, just use this one-liner from your shell script.
domain=$( echo $* | perl -ne '/domain\s([^\s]+)\s/ and print "$1"' )
Or if you'd rather just do it with sed:
domain=$( echo $* | sed 's/.*\<domain \([^ ]\+\).*/\1/' )
Whatever you want to call it, I'm trying to figure out a way to take the contents of an existing string and evaluate them as a double-quoted string. For example, if I create the following strings:
$string = 'The $animal says "meow"'
$animal = 'cat'
Then, Write-Host $string would produce The $animal says "meow". How can I have $string re-evaluated, to output (or assign to a new variable) The cat says "meow"?
How annoying...the limitations on comments makes it very difficult (if it's even possible) to include code with backticks. Here's an unmangled version of the last two comments I made in response to zdan below:
----------
Actually, after thinking about it, I realized that it's not reasonable to expect The $animal says "meow" to be interpolated without escaping the double quotes, because if it were a double-quoted string to begin with, the evaluation would break if the double quotes weren't escaped. So I suppose the answer would be that it's a two step process:
$newstring = $string -replace '"', '`"'
iex "`"$string`""
One final comment for posterity: I experimented with ways of getting that all on one line, and almost anything that you'd think works breaks once you feed it to iex, but this one works:
iex ('"' + ($string -replace '"', '`"') + '"')
Probably the simplest way is
$ExecutionContext.InvokeCommand.ExpandString($var)
You could use Invoke-Expression to have your string reparsed - something like this:
$string = 'The $animal says `"meow`"'
$animal = 'cat'
Invoke-Expression "Write-Host `"$string`""
Note how you have to escape the double quotes (using a backtick) inside your string to avoid confusing the parser. This includes any double quotes in the original string.
Also note that the first command should be a command, if you need to use the resulting string, just pipe the output using write-output and assign that to a variable you can use later:
$result = Invoke-Expression "write-output `"$string`""
As noted in your comments, if you can't modify the creation of the string to escape the double quotes, you will have to do this yourself. You can also wrap this in a function to make it look a little clearer:
function Invoke-String($str) {
$escapedString = $str -replace '"', '`"'
Invoke-Expression "Write-Output `"$escapedString`""
}
So now it would look like this:
# ~> $string = 'The $animal says "meow"'
# ~> $animal = 'cat'
# ~> Invoke-String $string
The cat says "meow"
You can use the -f operator. This is the same as calling [String]::Format as far as I can determine.
PS C:\> $string = 'The {0} says "meow"'
PS C:\> $animal = 'cat'
PS C:\> Write-Host ($string -f $animal)
The cat says "meow"
This avoids the pitfalls associated with quote stripping (faced by ExpandString and Invoke-Expression) and arbitrary code execution (faced by Invoke-Expression).
I've tested that it is supported in version 2 and up; I am not completely certain it's present in PowerShell 1.
Edit: It turns out that string interpolation behavior is different depending on the version of PowerShell. I wrote a better version of the xs (Expand-String) cmdlet with unit tests to deal with that behavior over here on GitHub.
This solution is inspired by this answer about shortening calls to object methods while retaining context. You can put the following function in a utility module somewhere, and it still works when you call it from another module:
function xs
{
[CmdletBinding()]
param
(
# The string containing variables that will be expanded.
[parameter(ValueFromPipeline=$true,
Position=0,
Mandatory=$true)]
[string]
$String
)
process
{
$escapedString = $String -replace '"','`"'
$code = "`$ExecutionContext.InvokeCommand.ExpandString(`"$escapedString`")"
[scriptblock]::create($code)
}
}
Then when you need to do delayed variable expansion, you use it like this:
$MyString = 'The $animal says $sound.'
...
$animal = 'fox'
...
$sound = 'simper'
&($MyString | xs)
&(xs $MyString)
PS> The fox says simper.
PS> The fox says simper.
$animal and $sound aren't expanded until the last two lines. This allows you to set up a $MyString up front and delay expansion until the variables have the values you want.
Invoke-Expression "`"$string`""
I have a string
$string = "Active Directory"
and I want to make another string
Active_Directory_Results.txt
I would like to just do
$otherstring = "$string.Replace(" ","_")_Results.txt"
but that doesn't work out. What would be the correct way to pull this off?
You should not use invoke-expression for that. The original answer is good:
$otherstring = $string.Replace(" ","_") + "_Results.txt"
But really, you can just use a $(subexpression):
$otherstring = "$($string.Replace(" ","_"))_Results.txt"
The $() tells PowerShell to evaluate that BEFORE defining the string.
As an alternative, you can also use string formatting:
$otherstring = "{0}_Results.txt" -f $string.Replace(" ","_")
Proving once again that with scripting languages, there's always more than one right way ...
I'm not on my windows machine right now, but how does $otherstring = $string.Replace(" ","_") + "_Results.txt" work?
Check the invoke-expression command. It allows you to execute code in a string.
Like:
PS> $command = '$otherstring = $string.Replace(" ","_") + "_Results.txt"'
PS> Invoke-Expression $command