Home
Reference Guides
Explore the Extended Definitions, OML Guides, Block Library, API Guide and Glossary.
Reference Guide for OpenMatrix Language Functions
The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
System Commands
getpid
Returns the current process ID.

What's New
Get Started
Tutorials
Model Components
Physical Component Modeling
Hydraulic System Modeling
Electrical System Modeling
Multibody Mechanical System Modeling
Electromagnetic System Modeling
Simulation Basics
Simulation Results
Block Libraries
Reference Guides
Keyboard Shortcuts

What's New
Discover new features and enhancements.
Get Started
New to Activate? Learn the basics here.
Tutorials
Start using Activate with our interactive tutorials.
Model Components
Learn about the components in Activate models.
Physical Component Modeling
Learn about modeling physical components.
Hydraulic System Modeling
Learn about modeling hydraulic systems with the Hydraulics (By Fluidon) library.
Electrical System Modeling
Learn about modeling electrical and electronic systems with Modelica and Spice.
Multibody Mechanical System Modeling
Learn about modeling multibody dynamic systems.
Electromagnetic System Modeling
Learn about modeling electromagnetic systems.
Simulation Basics
Learn how to set up, run, and troubleshoot simulations.
Simulation Results
Discover options to review, display, and export results.
Block Libraries
Learn about block libraries for building dynamic system models.
Reference Guides
Explore the Extended Definitions, OML Guides, Block Library, API Guide and Glossary.
- Extended Definitions for Advanced Users
  PDF file with in-depth information on key topics in the User's Guide.
- Scripting Guide for OpenMatrix Language
  OpenMatrix is a mathematical scripting language.
- Reference Guide for OpenMatrix Language Functions
  The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
  - ABF Commands
  - CAE Commands
  - Calculus Commands
  - Control System Commands
  - Core Minimal Interpreter Commands
  - Data Structure Commands
  - Differential Equations Commands
  - Elementary Math Commands
  - File I/O Commands
  - Geometry Commands
  - GUI Commands
  - HDF5 Reader Commands
  - HDF5 Writer Commands
  - Image Commands
  - Linear Algebra Commands
  - Logical Commands
  - Omlh3d Commands
  - Optimization Commands
  - Plotting Commands
  - Polynomial Math Commands
  - Signal Processing Commands
  - Statistical Analysis Commands
  - String Operations Commands
  - System Commands
    - cd
      Changes the current directory to dir.
    - chdir
      Changes the current directory to dir.
    - cputime
      Returns the current cputime used by Activate.
    - date
      Returns the current date as a string in the format DD-MMM-YYYY.
    - delete
      Deletes the file(s), f, or a graphic object, h.
    - diary
      Records all commands and outputs of an interactive session to a file. If no arguments are passed, the diary state is toggled. To save outputs when running a script (non-interactive session), use outputlog.
    - dir
      Directory listing of the current or specified directory.
    - dos
      Executes a dos command on Windows.
    - encryptfile
      Encrypts a OML file.
    - filesep
      Returns the path separator, dependent on the system.
    - genpath
      Creates a path with the directory and sub-directories under dir.
    - getpid
      Returns the current process ID.
    - ls
      Displays information and contents of file(s) or directories.
    - make_absolute_filename
      Creates an absolute path with input name, without checks made for the existance of the path on disk.
    - mkdir
      Creates the directory newdir in the current working directory by default.
    - outputlog
      Records all outputs to a file. If no arguments are passed, the outputlog state is toggled.
    - rmdir
      Removes the directory dir.
    - startupscript_edit
      Opens the user startup script for editing (GUI application only).
    - startupscript_path
      Shows the path to the user startup script.
    - system
      Executes the shell command stringCommand. If executed in 'sync' mode or without additional inputs, the application waits until the execution is complete. If executed in 'async' mode, stringCommand is executed in a detached thread and control is returned to the application immediately.
    - unix
      Executes the unix shell command stringCommand.
  - Time Commands
  - Trigonometry Commands
  - OML to Python Bridge Commands
  - Python to OML Bridge Commands
- Block Reference Guide
  Describes all of the blocks in the installed Activate library.
- Glossary
  Key terms associated with the software.
Keyboard Shortcuts
Define shortcuts to common operations.

Home
...
- Reference Guide for OpenMatrix Language Functions
  The Reference Guide contains documentation for all functions supported in the OpenMatrix language.
- Reference Guides
  Explore the Extended Definitions, OML Guides, Block Library, API Guide and Glossary.
- System Commands
getpid
Returns the current process ID.

What's New
Get Started
Tutorials
Model Components
Physical Component Modeling
Hydraulic System Modeling
Electrical System Modeling
Multibody Mechanical System Modeling
Electromagnetic System Modeling
Simulation Basics
Simulation Results
Block Libraries
Reference Guides
Keyboard Shortcuts

ON THIS PAGE

Syntax
Outputs
Examples

getpid

Returns the current process ID.

Syntax

R = getpid

Outputs

R: Current process ID.; Type: integer

Examples

Get the current process ID:

R = getpid

R = 16832

ON THIS PAGE

Syntax
Outputs
Examples

(c) 2025 Altair Engineering, Inc. All rights reserved.

Intellectual Property Rights Notice | Technical Support