Command execution times out in PowerShell 7.x.x but works in 6.x.x

[jayatdizzion]

Hi there, Commands like Get-Date, Get-Process, etc times out when executed using JPowerShell in PowerShell 7.x.x. The same work fine in version 6.x.x. Also this happens when PowerShell is running in a Docker container. Here is a sample program to reproduce this:

**import com.profesorfalken.jpowershell.PowerShell; import com.profesorfalken.jpowershell.PowerShellResponse; import java.util.HashMap; import java.util.Map;

public class psTester { public static void main (String[] args) { testPsCmd(); }

private static void testPsCmd() { String responseBody = ""; int responseCode = -1; try { PowerShell powerShell = PowerShell.openSession("pwsh"); Map<String, String> config = new HashMap<String, String>(); config.put("maxWait", "6000"); PowerShellResponse response = powerShell .configuration(config) .executeCommand("Get-Process"); responseCode = response.isError() ? 1 : 0; responseBody = response.getCommandOutput(); powerShell.close(); } catch (Exception e) { StringBuffer sb = new StringBuffer(e.getMessage()); } } }**

Here is a Dockerfile that can be used to spin up a container with JDK11 and PowerShell 7.2.7: **FROM amazoncorretto:11 as corretto_jdk

RUN yum install -y sudo RUN sudo yum install -y wget RUN sudo yum install -y tar RUN sudo yum install -y gzip RUN sudo yum install -y curl libunwind libicu libcurl openssl libuuid.x86_64

RUN curl -L -o /tmp/powershell.tar.gz https://github.com/PowerShell/PowerShell/releases/download/v7.2.7/powershell-7.2.7-linux-x64.tar.gz RUN sudo mkdir -p /opt/microsoft/powershell/7.2.7 RUN sudo tar zxf /tmp/powershell.tar.gz -C /opt/microsoft/powershell/7.2.7 RUN sudo chmod +x /opt/microsoft/powershell/7.2.7/pwsh RUN sudo ln -s /opt/microsoft/powershell/7.2.7/pwsh /usr/bin/pwsh RUN sudo ln -s /opt/microsoft/powershell/7.2.7/pwsh /usr/bin/powershell**

Please let me know if you need more information. Thanks

[jenskreidler]

Regarding the source code above, you're using Powershell/Unix. Despite having pwsh run <7.x, I am running as well into this issue. Tracing down the execution of jPowerShell on pwsh 7.x, jPowerShell hangs in PowerShellCommandProcessor at readLine(). I yet don't know why, but there are far more than one resource in the internet about "BufferedReader hanging...". What I know is, pwsh echoes some control characters too every time an output is read from the Process's outputstream jPowerShell captures.

I tracked it down to "CSI ? 1 h" and "CSI ? 1l" - special ANSI control sequences for the key cursor mode (https://vt100.net/docs/vt510-rm/chapter4.html - Table 4-8). I also attached a log image showing the pwsh output .

In my fork I provisionally changed that readLine to a character-wise read() implementation (no so efficient) - but jPowerShell is capable to run without hanging/blocking. On unix this also applies to the "getPID()", "isLastCommandInError()" and "exit" calls in PowerShell.java Atop of this, I strip undesired characters from the command output (to get rid of these control characters) - in the application using jPowerShell.