When I call a Powershell script, how can I keep the called script from closing its command window. I'm getting an error and I'm sure I can fix it if I could just read the error.
I have a Powershell script that sends an email with attachment using the .NET classes. If I call the script directly by executing it from the command line or calling it from the Windows Scheduler then it works fine. If I call it from within another script (IronPython, if that matters) then it fails. All scenarios work fine on my development machine. (I really do have to get that "Works on My Machine" logo!) I've got the call to Powershell happening in a way that displays a command window and I can see a flicker of red just before it closes.
Sorry: Powershell 1.0, IronPython 1.1
Solution: powershell -noexit d:\script\foo.ps1
The -noexit switch worked fine. I just added it to the arguments I pass from IronPython. As I suspected, it's something that I can probably fix myself (execution policy, although I did temporarily set as unrestricted with no effect, so I guess I need to look deeper). I'll ask another question if I run into trouble with that.
Thanks to all for the help. I learned that I need to investigate powershell switches a little more closely, and I can see quite a few things that will prove useful in the future.
Try with the -noexit switch:
powershell -noexit d:\script\foo.ps1
You basically have 3 options to prevent the PowerShell Console window from closing, that I describe in more detail on my blog post.
One-time Fix: Run your script from the PowerShell Console, or launch the PowerShell process using the -NoExit switch. e.g. PowerShell -NoExit "C:\SomeFolder\SomeScript.ps1"
Per-script Fix: Add a prompt for input to the end of your script file. e.g. Read-Host -Prompt "Press Enter to exit"
Global Fix: Change your registry key to always leave the PowerShell Console window open after the script finishes running.
Here are the registry keys to modify for option #3:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\Applications\powershell.exe\shell\open\command]
#="\"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe\" -NoExit \"& \\\"%1\\\"\""
[HKEY_CLASSES_ROOT\Microsoft.PowerShellScript.1\Shell\0\Command]
#="\"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe\" -NoExit \"-Command\" \"if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & \\\"%1\\\"\""
See my blog for more information and a .reg file that will apply these registry changes automatically.
I've needed this before and usually I didn't want to modify the script (typically for scripts fired off from the Task Scheduler). I just wanted to see what was spit out to console.
All you need to do is just append a Read-Host command after the script invocation e.g.:
PowerShell.exe -command { .\foo.ps1; read-host "Press enter key to continue" }
BTW the problem with using Start-Transcript is that it doesn't capture EXE output. And any form of attempted logging in V1 and even V2 with the standard host will not capture the verbose, debug, progress or warning streams. You can only see these by viewing the associated host window.
One cheesy but effective way to capture all script output (stdout, stderr, verbose, warning, debug) is to use another host like cmd.exe e.g.:
cmd.exe /c powershell.exe "$pwd\foo.ps1" > foo.log
I am generaly fine with scripts autoclosing except when an error occurs, where I need to see the error. Assuming you have not changed $ErrorActionPreference away from the default 'Continue', then for the behaviour I described do this at the end of you script
if ($Error)
{
Pause
}
There is no ordinary Try...Catch construction in Powershell; however you can trap exceptions instead and react properly.
I.E:
Function Example() {
trap [Exception] {
write-host "We have an error!";
write-error $("ERROR: " + $_.Exception.Message);
sleep 30;
break;
}
write-host "Hello world!";
throw "Something very bad has happened!";
}
You can also simulate Try...Catch construction:
Function Example2() {
${
write-host "Our try clause...";
throw "...caused an exception! It hurts!";
}
trap [Exception] {
write-error $_.Exception.Message;
sleep 30;
continue;
}
Of course as soon as you will trap an exception, you can log it, sleep, or whatever you want with the error message. My examples just sleep, allowing you to read what happened, but it's much better to log all the errors. (The simplest way is to redirect them with >>).
Look also at:
http://huddledmasses.org/trap-exception-in-powershell/
A quick and dirty solution is to use CTRL+S to halt the scrolling of the display and CTRL+Q to resume it.
You have three options:
Do a catch in the script (if using
Powershell V2)
Write a dummy
script which catches and redirects
stdout which you can then access as a
variable from your IronPython script.
VBS/Wscript Intro An addition to
this is just liberally drop
Read-Host commands everywhere,
and hit return to page through.
Rather than outputting anything to the shell, wrap your powershell script in a second script that redirects all output to a log file.
PS C:> myscript.ps1 |Out-File myscript.log
Create run_ps_script.bat file containing
#PowerShell.exe -command "try { %1 } finally { read-host 'Press ENTER...' }"
and make it default program to open PowerShell scrips.
My solution was to execute the script with a command line from the console window instead of right-clicking the file -> execute with powershell.
The console keeps displaying the error messages,
even though the execution of the script ended.
Have you thought about redirecting stdout and stderr to a file ex:
./ascript.ps1 >logs 2>&1
Note: You can create wrapper script in powershell that calls your powershell script with all necessary redirections.
My .PS1 script ran fine from the Powershell console but when "double-clicking" or "right-click open with powershell" it would exhibit the 'open/close' problem.
The Fix for me was to rename the script folder to a Name Without Spaces.
Then it all worked - Windows couldn't deal with
"C:\This is my folder\myscript.ps1" but
"C:\This_is_my_folder\myscript.ps1" worked just fine
A couple more ideas...You could use the start-sleep cmdlet at the end of you script to give you enough time to review the error.
You might also be able to use start-transcript to record the session to a text file.
Related
I have a PowerShell script, at its begining I added: $ErrorActionPreference = "Stop". It's good, if there is an error the script won't go further.
Fact is that when an error occurs, the script stop and exit itself and so, I can not see the error.
The best option is to crate a logfile that will write EVERYTHING that was in the PowerShell terminal, including succesful lines.
If not, at least make the terminal keep opened even if an error occurs, but stop the script.
I would recommend Start-Transcript:
The Start-Transcript cmdlet creates a record of all or part of a
PowerShell session to a text file. The transcript includes all command
that the user types and all output that appears on the console.
I have a powershell Script that runs fine in the ISE, but when I run it directly from the .ps1 file it stops at this point:
Write-Host "Attempting to start FFMPEG Process with arguments:$ArgumentList::::" -ForegroundColor Green
Start-Process $SCRIPT:FFMPEGLocation $ArgumentList -Wait
I get the Write-Host printout, with the correct Argument List, but no window pops up for the start-process or anything. I made sure to use the SCRIPT scope variable for anything that is outside the function. It runs fine in ISE just not when I run it in Console. No errors either, and the $SCRIPT:FFMPEGLocation variable is a direct path to the exe to be executed.
Any help would be greatly appreciated, and if you need more let me know.
PSVersion 5.1.14393.1066
OSVersion 10.0.14393
As per comments, check the value passed to Start-Process to ensure it contains what you expect as the issue is likely to be with $SCRIPT:FFMPEGLocation.
The difference between the ISE and Console with regard to scope can be frustrating.
See this SuperUser post which explains the behaviour further
. You may also find this post helpful;
BartekB explains that F5 in the ISE actually dot-sources the script instead of calling it, and provides a function to run a clean session.
An alternative method which will also wait on the process that needs to be run:
& $EXE /arg 1 /arg 2 -etc 2>&1 | % { $_ }
This will execute the command and pass the args, redirect any errors to the output stream and then print that output (for some reason, I've had bad luck with actually getting output from commands)
I have a script I wrote in PowerShell ISE that works perfectly.
It even works if I copy and paste it into regular PowerShell. However when I run it with regular PowerShell by making it the default program to open it with, then double-clicking, it just opens, displays some red text, and closes.
Is there a way to stop it from closing so I can view the red text or is this a common issue that can be fixed easily?
Try running from cmd prompt using:
powershell -noexit <path to the script>
Additionally, I think the error script may be throwing could be due to execution policy on your machine blocking the script from executing. Otherwise transcript would work. Ensure that the execution policy is set appropriately using Set-ExecutionPolicy cmdlet.
The practice of setting Powershell scripts to run when double clicked is highly discouraged for security reasons. Please ensure you are aware of the risks involved before you proceed.
You cannot simply 'make Powershell as default program' through the Windows Explorer interface. The Run with Powershell context menu option uses the following command:
"C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" "-Command" "if((Get-ExecutionPolicy ) -ne 'AllSigned') { Set-ExecutionPolicy -Scope Process Bypass }; & '%1'"
The "safest" way (bearing in mind the above caveat) to do what you are trying to achieve is to use Default Programs Editor to set the Run with Powershell context menu option to be the default.
All , I am trying to execute a external power shell script file in the MSBuild. But every time when PS run the cmdlet Read-Host. The MSBuild seems stop. and doesn't prompt me to input . I don't know what happen to it . Seems the console is in deadlock..thanks.
The testloop.ps1 code is shown below.
$ErrorActionPreference = 'Stop'
$error.clear()
function GetAzureSubScription()
{
read-host "please input something :"
}
write-host "Get into script"
GetAzureSubScription
The MSBuild code is below (wrapped for clarity):
<Exec WorkingDirectory="$(MSBuildProjectDirectory)"
Command="$(windir)\system32\WindowsPowerShell\v1.0\powershell.exe -f
E:\Work\AutoDeploy\testloop.ps1" />
So yes, the console (just a minor point - powershell.exe does not run under cmd.exe - they are separate processes, but they both use a console window) window is hidden so it will appear to freeze when prompting for input. The simplest option here is to override the read-host function with a version that will prompt using a graphical window. Add the start of your script, add the following function:
# override the built in prompting, just for this script
function read-host($prompt) {
$x = 0; $y = 0;
add-type -assemblyname microsoft.visualbasic
[Microsoft.VisualBasic.Interaction]::InputBox($prompt,
"Interactive", "(default value)", $x, $y)
}
Now your script will be able to prompt for values. Also, you should run powershell.exe with the -noninteractive argument to catch any other places where you are accidentally calling interactive host functions. It will not stop the above function from working though.
The MSBuild Exec tasks starts cmd.exe and let that execute the command. MSbuild has to channel the writes to the console through since the cmd.exe window itself is invisible. It seems the writes do get through, but the reads do not. You can see the same effect if instead of calling powershell you exec a command like "del c:\temp\somefile.txt /p" which asks for confirmation. Although that way it doesn't block, but there is also no way of giving an answer.
That it does not handle reads properly is not that strange. It is a build script, so it should just build and not ask questions. My advice is to have the MSBuild script run without asking questions. If you really need to ask questions, then ask them before calling MSBuild.
I'm using PowerShell v3.0 to start a new cmd.exe process, in which I then load up the Visual Studio Command Prompt to perform a build, like so:
Start-Process cmd.exe -ArgumentList $cmdArgumentsToRunMsBuildInVsCommandPrompt -WindowStyle $windowStyle -Wait
This works, and it opens a new command prompt window and I can see the build happen, and then when the build is finished the command prompt window closes. I would like to be able to get the text that is written to the command prompt window and store it in a variable, in order to inspect if the build passed or not. I tried using this, but it doesn't work; the $buildOutput variable is empty:
Start-Process cmd.exe -ArgumentList $cmdArgumentsToRunMsBuildInVsCommandPrompt -WindowStyle $windowStyle -Wait -OutVariable buildOutput
Write-Host "Build output = $buildOutput"
This makes sense since the cmd.exe process isn't returning any text; it is just writing it to it's own window. Is there a way for me to be able to store that text in a variable for the original powershell script to use? I know that I can provide a parameter to MsBuild to have it write the build log to a file, but I'm looking for a solution that doesn't involve writing to a log file and having to delete it later.
Any suggestions are appreciated. Thanks!
<# EDIT #>
Thanks for all of the responses so far! A popular suggestion has been to just call MsBuild.exe directly without using cmd.exe. The reason I need to go through cmd.exe is some projects don't build successfully if called directly from MsBuild.exe (e.g. XNA projects). Instead I need to call MsBuild.exe from the Visual Studio Command Prompt so that (I assume) all of the required environmental variables are set. I guess I could just call the VS Command Prompt directly, but it will have the same problem as calling cmd.exe too. If I can't find the VS Command Prompt I fallback to calling MsBuild.exe directly, so those answers are still appreciated.
You can always capture the output of console programs this way:
$output = [string](nuget.exe)
Here I used nuget ($output will contain the available commands list), but you can of course use msbuild.exe with the appropriate arguments.
I've solved my problem using a suggestion from the first comment on my question, which was to write the build output to a log file, consume it, then delete it. This allows me to still show the user the cmd window with the build progress if they need, as well inspect the build output once the build completes. It also still allows me to run the build in another process, so we can use PassThru if we don't want our script to wait for the build to complete before continuing execution.
I've created an Invoke-MsBuild powershell module to make building with MsBuild a snap while providing lots of parameters for additional functionality (returns if build succeeded or failed, can show/hide build window, can wait/not wait for build to finish, can automatically show build log on failed builds, etc.). You can view and download the script from my blog.
$process = New-Object System.Diagnostics.Process;
$process.StartInfo.UseShellExecute = $false;
$process.StartInfo.RedirectStandardOutput = $true;
$process.StartInfo.FileName = "cmd.exe";
$process.StartInfo.Arguments = $cmdArgumentsToRunMsBuildInVsCommandPrompt;
$process.Start();
$outputStream = $process.StandardOutput;
$outputStream.ReadToEnd();
You could also redirect StandardError.
edit: I ended up using #David Brabant's answer
I ran into this problem and created an echo function
function echo()
{
$input
}
which let me do this
$output = &"cmd.exe" $args | echo