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.