I am trying to execute the following powershell commands from CMD, for example:
powershell Get-WmiObject Win32_PnPSignedDriver
powershell Get-WmiObject Win32_PnPSignedDriver > test.txt
which both work correctly.
But when I do a query, for example:
powershell (Get-WmiObject Win32_PnPSignedDriver | where {$_.location -like "*PCI bus 0, device 22, function 0*"}).DeviceName
I am getting this message the cause of which I can not pin down:
INFO: Could not find files for the given pattern(s)
This seems to work for me (I was seeing the same error as you originally):
powershell -command "(Get-WmiObject Win32_PnPSignedDriver | where {$_.location -like '*PCI bus 0, device 22, function 0*'}).DeviceName"
To complement the existing answers with general guidelines for passing commands to powershell.exe from cmd.exe (a Command Prompt):
Enclose the entire PowerShell command in "..." (double quotes).
This protects its contents from unwanted up-front interpretation by cmd.exe - as happened with | in this case, as explained in aschipfl's answer.
However, cmd.exe-style environment-variable references (e.g., %USERNAME%) are still expanded.
For quoting that is embedded in the PowerShell command:
Use '...' (single quotes) where feasible; this is what Mark Wragg's helpful answer does, but it is only an option if the quoted string is meant to be a literal (doesn't contain variable references or subexpressions).
If you do need embedded "...", escape it as \"...\"
Note that while inside PowerShell it is the ` (backtick) that serves as the escape character, when passing strings from the outside PowerShell requires \.
Simplified examples (run from cmd.exe):
Note that passing a command without a parameter name implies the -Command parameter; run powershell -? to see the command-line syntax.
You may also want to use -NoProfile so that the user profile isn't loaded every time.
Commands that don't need embedded quoting - simply double-quote:
powershell -noprofile "get-date"
powershell -noprofile "(get-date).Date"
powershell -noprofile "get-date | get-member"
Commands with embedded quoting - use '...' or \"...\":
powershell -noprofile "(get-date).Year -like '*17'"
powershell -noprofile "$v=17; (get-date).Year -like \"*$v\""
Commands that incorporate the value of a cmd.exe environment variable:
:: # Nothing special to do: cmd.exe expands the reference irrespective of quoting.
set "v=17"
powershell -noprofile "(get-date).Year -like '*%v%'"
:: # More robust variant that passes the value as an argument to a script block.
set "v=17"
powershell -noprofile ". { param($v) (get-date).Year -like \"*$v\" }" "%v%"
Optional reading: calling powershell from POSIX-like shells such as bash:
The above rules apply analogously, except that you'll typically use '...' (single quotes) to enclose the entire PowerShell command, which categorically prevents up-front interpretation by the shell.
Using "..." is an option if up-front expansions of shell-variable references and command substitutions are explicitly desired, but the potential for confusion is great, because both POSIX-like shells and PowerShell use sigil $ to refer to variables - it may not be obvious what is expanded when.
POSIX-like shells categorically do not support embedding ' instances in side '...' strings, which necessitates a somewhat awkward workaround (see below).
Simplified examples (run from a POSIX-like shell such as bash):
Commands that don't need embedded quoting - simply single-quote:
powershell -noprofile 'get-date'
powershell -noprofile '(get-date).Date'
powershell -noprofile 'get-date | get-member'
Commands with embedded quoting - replace embedded ' instances with '\'' (sic) and use embedded " as-is:
powershell -noprofile '(get-date).Year -like '\''*17'\'''
powershell -noprofile '$v=17; (get-date).Year -like "*$v"'
Commands that incorporate the value of a shell/environment variable:
# By using a double-quoted string, the shell expands $v up front.
v=17
powershell -noprofile "(get-date).Year -like '*$v'"
# It gets trickier if you want to reference PS variables too.
# Note how the PS variable's $ is \-escaped so that the shell doesn't interpret it.
v=$HOME
powershell -noprofile "\$HOME -eq '$v'"
# More robust variant that passes the value as an argument to a script block.
v=17
powershell -noprofile '. { param($v) (get-date).Year -like "*$v" }' "$v"
I am pretty sure that the pipe character | is the problem here, because cmd tries to process it.
Simply escape it by preceding with ^:
powershell (Get-WmiObject Win32_PnPSignedDriver ^| where {$_.location -like "*PCI bus 0, device 22, function 0*"}).DeviceName
If this code is used within a parenthesised block of code in cmd, you may need to escape the closing ) as well (the opening ( can be escaped too, but there is no need):
powershell ^(Get-WmiObject Win32_PnPSignedDriver ^| where {$_.location -like "*PCI bus 0, device 22, function 0*"}^).DeviceName
Related
In WSL2 I want to run a powershell command and get the output of the command to print to stdout on my WSL2.
I have tried many variants but it seems I always just get the command given back and not its output:
$ pwsh.exe -Command {Get-Date}
Get-Date
$ pwsh.exe -Command '{Write-Output "hello"}'
Write-Output "hello"
You should not use curly braces here :
pwsh.exe -Command 'Get-Date'
Philippe's helpful answer provides the crucial pointer:
When calling pwsh, the PowerShell (Core) CLI, from outside PowerShell:
Do not use { ... } to enclose your command(s) - that only works from inside PowerShell.
Inside PowerShell, { ... } creates a script block literal, which is a reusable piece of PowerShell code that can be invoked on demand.
If you pass { ... } to pwsh from inside PowerShell, special processing happens behind the scenes, which notably preserves type fidelity in the output as much as possible - see this answer for details.
It should be noted that calling the PowerShell CLI from PowerShell is rarely necessary, except, for instance, on Windows, if you want to call the respective other PowerShell edition's CLI.
Instead, pass your command(s) as-is, inside a string.
If you pass a string to -Command from outside PowerShell with { ... } embedded, what happens is that PowerShell creates a script block and - in the absence of invoking it, with & or . - its string representation is output, which is the block's verbatim content (excluding { and }) - that is what you saw.
As an aside: There are many examples out there that use "& { ... }" as a -Command argument; while that technically works, it is unnecessary, and passing just "..." (or '...', from POSIX-compatible shells) is sufficient.
Thus:
# Simple case: no quoting necessary
$ pwsh.exe -Command Get-Date
# Command string that requires quoting:
$ pwsh.exe -Command 'Write-Output "hello"'
I'd like to learn to execute a PowerShell command from another shell or language, e.g. Python os.system(). What I want to achieve is the following:
Execute the PowerShell command
Tee the output to both the console and a file
Return the command exit code
I think this gives an idea of what I would like to achieve, assuming to use cmd.exe as the caller environmnet:
powershell -NoProfile -command "& { cat foo.txt | Tee-Object ps-log.txt; exit $LASTEXITCODE }"
echo %errorlevel%
There are some problems here. First, I cannot use quotations in the command, e.g. :
powershell -NoProfile -command "& { cat `"foo bar.txt`" | Tee-Object ps-log.txt; exit $LASTEXITCODE }"
The cat argument seems to be passed unquoted and so cat looks for a 'bar.txt' parameter.
I think $LASTEXITCODE is expanded soon, that is before cat is executed.
& is inconvenient to use, because it does not accept a single command line string including arguments. An alternative to & is iex, however I cannot use it from cmd.exe. In fact:
powershell -NoProfile -command {iex cat foo.txt}
returns:
iex cat foo.txt
From cmd.exe, use the following (-c is short for -Command):
C:\>powershell -NoProfile -c "Get-Content \"foo bar.txt\" | Tee-Object ps-log.txt; exit -not $?"
There's no reason to use & { ... } in a string passed to -Command - just use ... instead.
Escape embedded " chars. as \" (PowerShell (Core) 7+ also accepts "").
Alternatively, as marsze's helpful answer points out, you can use '...' (single-quoting) inside the "..." string passed to -Command / -c, assuming that no string interpolation is required.
Since only PowerShell-native commands are involved in the command (on Windows, cat is simply an alias of Get-Content), $LASTEXITCODE is not set, as it only reflects the exit code of external programs. Instead, the automatic $? variable applies, which is a Boolean that indicates whether any errors were emitted by the commands in the most recently executed pipeline.
Negating this value with -not means that $true is converted to $false and $false to $true, and these values are converted to integers for the outside, with $false mapping to 0 and $true to 1.
Powershell supports single quotes, which saved me in such situations quite a lot of times. The good thing about it: They are unambiguous and easy to read. But mind that variable expansion won't work inside single-quoted strings.
powershell -NoProfile -command "cat 'foo bar.txt' | tee ps-log.txt"
Apart from that, have a look at the useful advice in mklement0's answer.
I have this command that works ok on powershell
Compare-Object (Get-Content "tex1.txt") (Get-Content "tex2.txt") | Where-Object{$_.SideIndicator -eq "<="} | select inputobject | ft -hidetableheaders
I'm trying to running in cmd by doing this:
powershell -Command " & {Compare-Object (Get-Content "tex1.txt") (Get-Content "tex2.txt") | Where-Object{$_.SideIndicator -eq "<="} | select inputobject | ft -hidetableheaders}"
but it says something like: the name, the directory or the volume syntax is incorrect (is in spanish so i dont know the exact translation)
I think the problem is the pipes, since running everything before the pipe: Compare-Object (Get-Content "tex1.txt") (Get-Content "tex2.txt") works
PD: I also tried to write ^ before the pipes but I haven't succeeded.
tl;dr
When calling the PowerShell CLI (powershell.exe for Windows PowerShell, pwsh for the cross-platform PowerShell [Core] 6+ edition):
Using embedded " in an overall "..." string comes with escaping challenges.
If feasible for a given command, formulating it without embedded " is the easiest solution:
powershell -Command "Compare-Object (Get-Content tex1.txt) (Get-Content tex2.txt) | Where-Object {$_.SideIndicator -eq '<='} | select inputobject | ft -hidetableheaders"
Read on, if you do need to use embedded ".
eryksun points out that your problem is your lack of escaping of embedded " chars. inside the overall "..." string, which causes cmd.exe to see multiple strings, including parts it considers unquoted, which causes problems with special characters such as | and < - they never reach PowerShell.
Nesting double-quote strings from cmd.exe is tricky business:
To make cmd.exe happy, you need to double the embedded " chars. ("")
Separately, to make powershell.exe happy, you need to \-escape " chars.
Note: PowerShell [Core] 6+, the cross-platform edition, on Windows now also accepts "" by itself, which is the most robust choice.
Generally, dealing with quoting and escaping arguments when calling from cmd.exe is a frustrating experience with no universal solutions, unlike in the Unix world. Sadly, PowerShell has its own challenges, even in the Unix world.[1]
In short: Escape embedded " chars. when calling the Windows PowerShell CLI, powershell.exe, from cmd.exe as follows (for the PowerShell (Core) 7+ CLI, pwsh.exe, "" is the robust choice):
Use "^"" (sic) when using powershell.exe -Command, which works robustly.
Caveat: "^"" does not work for calling other programs.
This saves you from additional escaping, as would be necessary if you used \"
Example: powershell -command " Write-Output "^""a & b"^"" " yields a & b, as expected, and the & didn't need escaping.
If you use the simpler - and customary - \", you may need to perform additional escaping: Specifically, you must individually ^-escape the following cmd.exe metacharacters with ^ inside \"...\" runs: & | < > ^Thanks, LotPings.
Example: powershell -command " Write-Output \"a ^& b\" " yields a & b; that is, the & needed escaping with ^.
Additionally, to treat % (and, with enabledelayedexpansion , !) verbatim, the escaping syntax unfortunately depends on whether you're calling from the command line or a batch file: use %^USERNAME% (!^USERNAME) from the former, and %%USERNAME%% (^!USERNAME^! / ^^!USERNAME^^! inside \"...\" runs) from the latter - see this answer for the gory details.
It is unfortunate that cmd.exe makes use of \" treacherous, given that it is supported by virtually all programs (except batch files), and if it weren't for these extra escaping requirements, command lines that use it have the potential to work across different platforms and shells - with the notable exception of calling from PowerShell, where, sadly, an additional layer of escaping is needed and " inside "..." must be escaped as \`" (sic); see this answer.
See the bottom section for ways to ease the escaping pain by avoiding use of nested ".
Other programs, including PowerShell Core:
Use just "" for programs compiled with Microsoft compilers and, on Windows, also Python and Node.js as well as PowerShell Core (pwsh.exe).
Regrettably, this robust option does not work with powershell.exe, i.e. Windows PowerShell.
Use \" for programs with Unix heritage, such as Perl and Ruby - which comes with the escaping headaches discussed above.
Avoiding embedded ":
When you call PowerShell's CLI, you can often get away without needing to embed double quotes:
There may be arguments in your string that don't require quoting at all, such as text1.txt and text2.txt
You can alternatively use single-quoting ('...') inside the overall command string, which require no escaping; note that such strings, from PowerShell's perspective, are string literals.
To put it all together:
powershell -Command "Compare-Object (Get-Content tex1.txt) (Get-Content tex2.txt) | Where-Object {$_.SideIndicator -eq '<='} | select inputobject | ft -hidetableheaders"
Note that I've also removed the & { ... } around your command, as it isn't necessary.
[1] eryksun puts it as follows: "This is the inescapable frustration of the Windows command line. Every program parses its own command line, using whatever rules it wants. So the syntax of a command line has to work with not only the shell (CMD) but also all programs invoked in the pipeline. In the Unix world the shell parses the command line into argv arrays, so typically you only have to get the syntax right to make the shell happy."
The problems with PowerShell Core, even on Unix, stem from how it re-quotes arguments behind the scenes before passing them on - see this GitHub docs issue.
I'm trying to run a PowerShell script from Windows cmd.exe. The input to the PowerShell script is a string, which contains newline characters using PowerShell backtick escaping - i.e:
`r`n
For demonstration purposes, the input string is then written to the console, and also dumped to a file.
The issue I have is that when the script is run from cmd.exe using the syntax
powershell.exe script.ps1 "TEST`r`nTEST"
The newline characters in the string are not treated as newline, and are included literally in both the console output and the output text file.
TEST`r`nTEST
However, if I run this from a PowerShell environment, I get the expected result (i.e. the newline characters are parsed correctly, and a newline is inserted in the appropriate location).
TEST
TEST
Similarly, if I pass in \r\n instead of the escaped newline characters through Windows cmd.exe, and do a .replace in the PowerShell script
$date = $data.replace("\r\n","`r`n")
I get the expected output:
TEST
TEST
Is anyone able to shed some light on why this happens?
The test script is as follows:
param([string]$data) # data to send
Write-Host $data
[IO.File]::WriteAllText('d:\temp.txt', $data)
return 0
And the file is called from the command line as:
powershell.exe script.ps1 "TEST`r`nTEST"
The script is running on Windows Server 2012 R2, using PowerShell v4.0
tl;dr
Use -Command and pass the entire PowerShell command as a single string; e.g.:
C:\> powershell -NoProfile -Command "script.ps1 \"TEST`r`nTEST\""
TEST
TEST
Note how the internal " instances are escaped as \", which PowerShell requires when called from the outside (alternatively, for full robustness, use "^"" (sic) in Windows PowerShell and "" in PowerShell (Core) v6+).
In your specific case,
powershell -NoProfile -Command script.ps1 "TEST`r`nTEST" would have worked too, but generally that only works as intended if the string has no embedded spaces.
Given that -Command is the default up to PSv5.1, your command - as currently posted - should work as-is.
As of PowerShell v5.1, arguments passed to powershell.exe from the outside:
ARE subject to interpretation by PowerShell, including string interpolation, by default and when you use -Command (i.e., specifying neither -File nor -Command currently defaults to -Command).
Caveat: The default behavior will change in v6: -File will be the default then - see the relevant change on GitHub.
are NOT subject to interpretation if you use -File to invoke a script - (after potential interpretation by cmd.exe) PowerShell treats all arguments as literal strings.
Caveat: This behavior is currently being discussed with respect to v6, given that it is overtly problematic in at least one case: trying to pass Boolean values.
Optional reading: Why you should pass the entire PowerShell command as a single argument when using -Command:
When you use -Command with multiple arguments, PowerShell essentially assembles them into a single command line behind the scenes before executing it.
Any "..."-quoting around the individual arguments is lost in the process, which can have unexpected results; e.g.:
C:\> powershell -NoProfile -Command "& { $args.count }" "line 1`r`nline 2"
3 # !! "line 1`r`nline 2" was broken into 3 arguments
Given that the outer "..." quoting was removed in the process of parsing the command line, the actual command line that PowerShell ended up executing was:
C:\ PS> & { $args.Count } line 1`r`nline 2
3
To illustrate why, let's look at an equivalent command that uses explicit quoting:
C:\ PS> & { $args.Count } "line" "1`r`nline" "2"
In other words: After the enclosing " were removed, the resulting token was broken into multiple arguments by spaces, as usual.
The parameter will need to be reinterpreted as a PowerShell string. Will this get you down the road?
The reason your -replace did not work is that the original string actually contains a backtick. It needs to be escaped in the search string.
C:\src\t>type p1.ps1
Param([string]$s)
Write-Host $s
$p = Invoke-Expression `"$s`"
Write-Host $p
$p2 = $s -replace "``r``n","`r`n"
Write-Host $p2
C:\src\t>powershell -noprofile -file .\p1.ps1 "TEST`r`nTEST"
TEST`r`nTEST
TEST
TEST
TEST
TEST
Carriage return and Linefeed are bytes with values 13 and 10, you can't write them, you can't see them.
As a convenience, when writing PowerShell code, the language will let you write:
"`r`n"
in a double quoted string, and when processing PowerShell source code (and at no other time), it will read those and replace them with bytes value 13 and 10.
It is this line of code in the PowerShell tokenizer which does it.
There is nothing special about backtick-n to the cmd.exe interpreter, and nothing special about having it in a string - you can put it there in a single quoted string
'`n'
or replacing it in a string - except that you have to note when the replacement happens. e.g. in your comment:
For example, if you pass in 'r'n and then replace 'r'n with 'r'n, the 'r'n is still output literally
Because your code
-replace "`r`n"
becomes
-replace "[char]13[char]10"
and your string passed in from outside contains
`r`n
and they don't match. Backtick-n in a string isn't magic, strings are not all interpreted by the PowerShell engine as PowerShell code, nor are parameters, or anything. And it's only in that context - when you write your -replace code, that is when the swap for actual newline characters happens.
I can download a file to a constant location from cmd console using powershell like this
C:\Users\Weijun>powershell -command "(new-object System.Net.WebClient).DownloadFile('https://example.com/example.zip', 'D:\example.zip')"
but i need to download it to system temp directory,using the powershell variable $env:temp,the following doesn't work.(variable not expanded in single-quote)
powershell -command "(new-object System.Net.WebClient).DownloadFile('https://example.com/example.zip', '$env:temp\example.zip')"
how to pass variable as parameter in method invoke?
UPDATE: it is a typo for $env:temp:,I amend it.
tl;dr:
From outside of PowerShell (cmd.exe - Command Prompt or batch file), use escaped double-quoted strings - \"...\" - inside the overall command string - "..." - passed to powershell -command for strings that need interpolation (e.g., expansion of variable references such as $env:temp):
powershell -command "(new-object System.Net.WebClient).DownloadFile('https://example.com/example.zip', \"$env:temp\example.zip\")"
You not only need to fix the incidental problem that Nkosi points out - removing the extraneous : at the end of $env:temp: - but you must generally either not quote the path at all (argument syntax), or use escaped double quotes (expression syntax or values with shell metacharacters) - single-quoted strings don't work, because PowerShell treats their content as a literal and won't expand the environment-variable reference.[1]
For a description of PowerShell's two fundamental parsing modes - argument syntax vs. expression syntax - see Get-Help about_Parsing.
Simplified examples:
Without quoting (argument syntax):
c:\>powershell.exe -noprofile -command "write-output $env:temp\example.zip"
C:\Users\jdoe\AppData\Local\Temp\example.zip
With double-quoting (expression syntax or if the value contains shell metacharacters such as , or |):
c:\>powershell.exe -noprofile -command "write-output \"$env:temp\example.zip\""
C:\Users\jdoe\AppData\Local\Temp\example.zip
Note: When called from the outside, PowerShell requires embedded " chars. to be escaped as \" - unlike inside PowerShell, where `" must be used.
Applied to your command: with (escaped) double-quoting, which is needed, because you're using .NET method syntax, which is parsed with expression syntax:
powershell -command "(new-object System.Net.WebClient).DownloadFile('https://example.com/example.zip', \"$env:temp\example.zip\")"
[1] If you run the same command from PowerShell, you won't see the problem, because the command as a whole is enclosed in "...", which means that the current PowerShell session will expand $env:temp - before it is passed to powershell.exe.
However, when called from cmd.exe, this interpolation is NOT applied - hence the need to either omit quoting or use embedded (escaped) double-quoting.
I would use Invoke-WebRequest with -OutFile:
powershell -command "Invoke-WebRequest -Uri 'http://example.com/file-to-get.txt' -OutFile $env:temp\file-to-get.txt"
NB this requires PowerShell 3.0 (if I remember correctly).