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‎README.md

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# PowerShellLibJava
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A simple library for using PowerShell from Java.
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## Usage
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`PowerShell.open()` opens a new PowerShell session. You can execute a PowerShell command with `psSession.executeCommands(command)`. It will return the output of the command as a string:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("Write-Output 'hello Java'"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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hello Java
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```
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---
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You can also execute multiple lines of commands at once:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands(
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"for ($i = 1; $i -le 5; $i++) {",
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" Write-Output $i",
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"}"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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1
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5
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```
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---
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If your PowerShell code has parameters that are dynamically read from Java strings, they might contain characters that have special meaning in PowerShell (kind of like SQL injection). You can sanitize your input with `PowerShell.escapePowerShellString(parameter)`:
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```java
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String param = "thi's won't bre;ak' the' code";
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("Write-Output " + PowerShell.escapePowerShellString(param)));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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thi's won't bre;ak' the' code
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```
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---
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If there is an error on executing the command, a `PowerShellExecutionException` is thrown:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("this is not a valid command"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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tuupertunut.powershelllibjava.PowerShellExecutionException: Error while executing PowerShell commands:
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this : The term 'this' 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.
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...
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```
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## Requirements
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You must have PowerShell installed on your machine.
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**OS:** Windows is the only currently supported OS. This library has not been tested on Linux, but it might work.
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**Java:** Java 8 or higher is required.
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## Maven Central
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[![https://mvnrepository.com/artifact/com.github.tuupertunut/powershell-lib-java](https://img.shields.io/maven-central/v/com.github.tuupertunut/powershell-lib-java.svg?style=for-the-badge)](https://mvnrepository.com/artifact/com.github.tuupertunut/powershell-lib-java)
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**groupId:** com.github.tuupertunut
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**artifactId:** powershell-lib-java
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# PowerShellLibJava
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A simple library for using PowerShell from Java.
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## Usage
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`PowerShell.open()` opens a new PowerShell session with default executable. On Windows it is `powershell`, and on other platforms it is `pwsh` from PowerShell Core. You can also specify a custom PowerShell executable, for example `PowerShell.open("/usr/bin/pwsh-preview")`.
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You can execute a PowerShell command with `psSession.executeCommands(command)`. It will return the output of the command as a string:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("Write-Output 'hello Java'"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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hello Java
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```
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---
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You can also execute multiple lines of commands at once:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands(
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"for ($i = 1; $i -le 5; $i++) {",
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" Write-Output $i",
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"}"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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1
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2
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3
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4
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5
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```
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---
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If your PowerShell code has parameters that are dynamically read from Java strings, they might contain characters that have special meaning in PowerShell (kind of like SQL injection). You can sanitize your input with `PowerShell.escapePowerShellString(parameter)`:
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```java
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String param = "thi's won't bre;ak' the' code";
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("Write-Output " + PowerShell.escapePowerShellString(param)));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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thi's won't bre;ak' the' code
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```
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---
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If there is an error on executing the command, a `PowerShellExecutionException` is thrown:
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```java
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try (PowerShell psSession = PowerShell.open()) {
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System.out.println(psSession.executeCommands("this is not a valid command"));
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} catch (IOException | PowerShellExecutionException ex) {
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ex.printStackTrace();
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}
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```
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```
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tuupertunut.powershelllibjava.PowerShellExecutionException: Error while executing PowerShell commands:
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this : The term 'this' 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.
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...
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```
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## Requirements
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**OS:** Works on every platform that has PowerShell available.
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**PowerShell:** On Windows 7 and newer, Windows PowerShell is installed by default and this library should work with it out of the box. On other platforms, you need to have PowerShell Core (https://github.com/PowerShell/PowerShell) installed.
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**Java:** Java 8 or higher is required.
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## Maven Central
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[![https://mvnrepository.com/artifact/com.github.tuupertunut/powershell-lib-java](https://img.shields.io/maven-central/v/com.github.tuupertunut/powershell-lib-java.svg?style=for-the-badge)](https://mvnrepository.com/artifact/com.github.tuupertunut/powershell-lib-java)
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**groupId:** com.github.tuupertunut
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**artifactId:** powershell-lib-java

‎src/main/java/com/github/tuupertunut/powershelllibjava/PowerShell.java

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/**
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* PowerShell session that can be used to execute PowerShell commands. An
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* instance of this class can be created with {@link #open()}. Instances should
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* always be closed with {@link #close()} to free resources.
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* instance of this class can be created with {@link #open()} or
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* {@link #open(java.lang.String)}. Instances should always be closed with
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* {@link #close()} to free resources.
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*
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* @author Tuupertunut
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*/
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public class PowerShell implements Closeable {
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private static final String DEFAULT_WIN_EXECUTABLE = "powershell";
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private static final String DEFAULT_CORE_EXECUTABLE = "pwsh";
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/* This string marks the end of command output. It should be as unique as
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* possible. This library assumes that the string never occurs as a
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* substring in any powershell command output. If that happens, behavior is
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private boolean closed;
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private PowerShell() throws IOException {
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private PowerShell(String psExecutable) throws IOException {
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/* cmd /c chcp 65001 : Set console codepage to UTF-8, so that input and
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* output streams of the console will be interpreted as UTF-8.
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*
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* > NUL : Discard any output from the codepage change command.
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*
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* & powershell : If codepage change was successful, start powershell.
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*
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* -ExecutionPolicy Bypass : Disable any prompts about unsigned scripts,
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* because there is no way to answer prompts.
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*
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* -NoExit : Keep the session open after executing the first command.
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*
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* -Command - : Read commands from standard input stream of the process. */
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psSession = new ProcessBuilder("cmd", "/c", "chcp", "65001", ">", "NUL", "&", "powershell", "-ExecutionPolicy", "Bypass", "-NoExit", "-Command", "-").start();
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psSession = createProcessBuilder(psExecutable).start();
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commandOutput = new BufferedReader(new InputStreamReader(psSession.getInputStream(), StandardCharsets.UTF_8));
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commandErrorOutput = new BufferedReader(new InputStreamReader(psSession.getErrorStream(), StandardCharsets.UTF_8));
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closed = false;
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}
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private static ProcessBuilder createProcessBuilder(String psExecutable) {
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/* Windows needs some extra configuration to understand UTF-8. */
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if (isWindows()) {
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/* cmd /c chcp 65001 : Set console codepage to UTF-8, so that input
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* and output streams of the console will be interpreted as UTF-8.
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*
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* > NUL : Discard any output from the codepage change command.
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*
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* & *psExecutable* : If codepage change was successful, start
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* powershell.
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*
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* -ExecutionPolicy Bypass : Disable any prompts about unsigned
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* scripts, because there is no way to answer prompts.
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*
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* -NoExit : Keep the session open after executing the first
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* command.
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*
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* -Command - : Read commands from standard input stream of the
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* process. */
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return new ProcessBuilder("cmd", "/c", "chcp", "65001", ">", "NUL", "&", psExecutable, "-ExecutionPolicy", "Bypass", "-NoExit", "-Command", "-");
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} else {
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return new ProcessBuilder(psExecutable, "-ExecutionPolicy", "Bypass", "-NoExit", "-Command", "-");
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}
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}
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/* Apache commons says this is a valid way to detect Windows.
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* https://github.com/apache/commons-lang/blob/LANG_3_7/src/main/java/org/apache/commons/lang3/SystemUtils.java */
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private static boolean isWindows() {
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return System.getProperty("os.name").startsWith("Windows");
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}
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private static String getDefaultExecutable() {
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if (isWindows()) {
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return DEFAULT_WIN_EXECUTABLE;
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} else {
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return DEFAULT_CORE_EXECUTABLE;
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}
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}
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/**
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* Opens a new PowerShell session.
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* Opens a new PowerShell session with default executable. On Windows, the
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* default executable is "powershell" from Windows PowerShell, and on other
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* platforms it is "pwsh" from PowerShell Core.
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*
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* @return a new PowerShell session.
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* @throws IOException if an IOException occurred on process creation.
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*/
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public static PowerShell open() throws IOException {
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return new PowerShell();
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return new PowerShell(getDefaultExecutable());
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}
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/**
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* Opens a new PowerShell session with the provided executable.
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*
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* @param customExecutable the PowerShell executable. Can be an executable
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* name like "pwsh" or a path to the executable file.
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* @return a new PowerShell session.
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* @throws IOException if an IOException occurred on process creation.
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*/
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public static PowerShell open(String customExecutable) throws IOException {
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return new PowerShell(customExecutable);
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}
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/**

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