Shell (Windows)

Run commands and scripts on Windows using PowerShell, pwsh, or cmd.exe.

Configure the Shell

• DAG defaults (literal values):

  shell: powershell -NoProfile
  steps:
    - run: Write-Host "Runs with PowerShell"

• Step override (evaluated at runtime so params/secrets/outputs are allowed):

  steps:
    - run: Write-Host "Runs in the step shell"
      with:
        shell: ${SHELL_OVERRIDE:-pwsh -NoProfile}

• Fallback: If no shell is set, Dagu prefers PowerShell, then pwsh, then cmd.exe.
• String or array: shell accepts either "powershell -NoProfile" or ["powershell", "-NoProfile"]; arrays avoid quoting issues.

Running Commands

• Inline command string:

  steps:
    - run: Write-Host "Hello from PowerShell"
    - run: echo Hello from cmd
      with:
        shell: cmd
    - run: |
        @echo off
        echo Multi-line command block
        echo Runs as a script (not split into args)
      with:
        shell: cmd

• Structured direct exec:

  steps:
    - action: exec
      with:
        command: C:\Windows\System32\cmd.exe
        args:
          - /c
          - echo
          - Hello from cmd argv

• Script block:

  steps:
    - run: |
        Write-Host "Multi-line script"
        Get-Date
      with:
        shell: powershell

  Scripts are saved as .ps1 files and executed with the selected shell.
• Interpreter + inline script:

  steps:
    - run: |
        Write-Host "Inline ps1 body"
      with:
        shell: powershell

• Working directory and env: Use working_dir and env on the step (or DAG defaults) to control context.

Script Behavior (Windows)

• A run: block is saved to a temp file in the working directory when possible and removed after the step finishes.
• With PowerShell/pwsh, the script is stored as .ps1 and executed by the selected shell. Dagu prefixes each script with $ErrorActionPreference = 'Stop' and $PSNativeCommandUseErrorActionPreference = $true so cmdlet errors and native command failures stop execution. With cmd, scripts follow cmd semantics; use PowerShell for richer scripting.
• When both shell and a multi-line run block are set, the shell value is used as the interpreter.

Shell Options

• PowerShell / pwsh
  Use DAG-level shell: powershell/shell: pwsh, or step-level with.shell: powershell/with.shell: pwsh. Script blocks become .ps1 files and are prefixed with $ErrorActionPreference = 'Stop' plus $PSNativeCommandUseErrorActionPreference = $true for fail-fast behavior on cmdlet errors and native command exit codes (PowerShell 7.4+). Use PowerShell syntax for variables/pipelines.

• cmd.exe
  Set DAG-level shell: cmd, or step-level with.shell: cmd, for command prompt semantics. Include /c in the shell string/array when you want to run a single command string. For multi-line cmd scripts, embed the batch pattern directly in YAML:

  steps:
    - run: |
        @echo off
        rem Command || (What to do if it fails)
        copy file.txt destination_folder\ || exit /b 1
  
        echo This line runs only if the copy succeeded.
      with:
        shell: cmd

• Direct execution (no shell parsing)
  Use action: exec for explicit argv:

  steps:
    - action: exec
      with:
        command: "C:\\Program Files\\Git\\bin\\bash.exe"
        args:
          - -c
          - echo from bash in direct mode

  action: exec bypasses shell parsing and uses explicit with.command / with.args.

Tips

• Prefer action: exec when you need explicit argv with flags.
• Choose PowerShell for richer scripting; use cmd only when you need cmd.exe semantics.
• Keep DAG-level shells stable; override per-step only when a different interpreter is required.
• For .ps1/.cmd/.bat scripts in the working directory, use explicit relative or absolute paths to avoid PATH lookup issues.