TProcess¶

Class to start and control other processes.

Declaration¶

Source position: processbody.inc line 117

type

  TProcess = class(TComponent)
  public
    constructor Create;
    destructor Destroy;
    procedure Execute;
    procedure CloseInput;
    procedure CloseOutput;
    procedure CloseStderr;
    function Resume : Integer;
    function Suspend : Integer;
    function Terminate : Boolean;
    function WaitOnExit : Boolean;
    function WaitOnExit(Timeout: DWord) : Boolean;
    function ReadInputStream(p: TInputPipeStream; var BytesRead: Integer; 
                        var DataLength: Integer; var Data: string; 
                        MaxLoops: Integer=10) : Boolean;
    function ReadInputStream(p: TInputPipeStream; data: TStream; 
                        MaxLoops: Integer=10) : Boolean;
    function RunCommandLoop : Integer;
    property WindowRect: Trect; {rw}
    property Handle: THandle; {r}
    property ProcessHandle: THandle; {r}
    property ThreadHandle: THandle; {r}
    property ProcessID: Integer; {r}
    property ThreadID: Integer; {r}
    property Input: TOutputPipeStream; {r}
    property Output: TInputPipeStream; {r}
    property Stderr: TInputPipeStream; {r}
    property ExitStatus: Integer; {r}
    property ExitCode: Integer; {r}
    property InheritHandles: Boolean; {rw}
    property OnRunCommandEvent: TOnRunCommandEvent; {rw}
    property RunCommandSleepTime: Integer; {rw}
    property OnForkEvent: TProcessForkEvent; {rw}
  published
    property PipeBufferSize: Cardinal; {rwd}
    property Active: Boolean; {rw}
    property ApplicationName: TProcessString; {rw}
    property CommandLine: TProcessString; {rw}
    property Executable: TProcessString; {rw}
    property Parameters: TProcessStrings; {rw}
    property ConsoleTitle: TProcessString; {rw}
    property CurrentDirectory: TProcessString; {rw}
    property Desktop: string; {rw}
    property Environment: TProcessStrings; {rw}
    property Options: TProcessOptions; {rw}
    property Priority: TProcessPriority; {rw}
    property StartupOptions: TStartupOptions; {rw}
    property Running: Boolean; {r}
    property ShowWindow: TShowWindowOptions; {rw}
    property SkipCommandLineQuotes: Boolean; {rw}
    property WindowColumns: Cardinal; {rw}
    property WindowHeight: Cardinal; {rw}
    property WindowLeft: Cardinal; {rw}
    property WindowRows: Cardinal; {rw}
    property WindowTop: Cardinal; {rw}
    property WindowWidth: Cardinal; {rw}
    property FillAttribute: Cardinal; {rw}
    property XTermProgram: string; {rw}
    property InputDescriptor: TIODescriptor; {rw}
    property OutputDescriptor: TIODescriptor; {rw}
    property ErrorDescriptor: TIODescriptor; {rw}
  end;

Inheritance¶

Description¶

TProcess is a component that can be used to start and control other processes (programs/binaries). It contains a lot of options that control how the process is started. Many of these are Win32 specific, and have no effect on other platforms, so they should be used with care.

The simplest way to use this component is to create an instance, set the CommandLine property to the full pathname of the program that should be executed, and call Execute. To determine whether the process is still running (i.e. has not stopped executing), the Running property can be checked.

More advanced techniques can be used with the Options settings.

Properties¶

Member	Visibility	Description
Active	published	Start or stop the process.
ApplicationName	published	Name of the application to start (deprecated).
CommandLine	published	Command-line to execute (deprecated).
ConsoleTitle	published	Title of the console window.
CurrentDirectory	published	Working directory of the process.
Desktop	published	Desktop on which to start the process.
Environment	published	Environment variables for the new process.
ErrorDescriptor	published
Executable	published	Executable name. Supersedes CommandLine and ApplicationName.
ExitCode read only	public	Exit code of the process.
ExitStatus read only	public	Exit status of the process.
FillAttribute	published	Color attributes of the characters in the console window (Windows only).
Handle read only	public	Handle of the process.
InheritHandles	public	Should the created process inherit the open handles of the current process.
Input read only	public	Stream connected to standard input of the process.
InputDescriptor	published
Options	published	Options to be used when starting the process.
Output read only	public	Stream connected to standard output of the process.
OutputDescriptor	published
Parameters	published	Command-line arguments. Supersedes CommandLine.
PipeBufferSize	published	Buffer size to be used when using pipes.
Priority	published	Priority at which the process is running.
ProcessHandle read only	public	Alias for Handle.
ProcessID read only	public	ID of the process.
RunCommandSleepTime	public	Sleep time between attempts to collect data.
Running read only	published	Determines whether the process is still running.
ShowWindow	published	Determines how the process main window is shown (Windows only).
SkipCommandLineQuotes	published
StartupOptions	published	Additional (Windows) startup options.
Stderr read only	public	Stream connected to standard diagnostic output of the process.
ThreadHandle read only	public	Main process thread handle.
ThreadID read only	public	ID of the main process thread.
WindowColumns	published	Number of columns in console window (windows only).
WindowHeight	published	Height of the process main window.
WindowLeft	published	X-coordinate of the initial window (Windows only).
WindowRect	public	Positions for the main program window.
WindowRows	published	Number of rows in console window (Windows only).
WindowTop	published	Y-coordinate of the initial window (Windows only).
WindowWidth	published	Height of the process main window (Windows only).
XTermProgram	published	XTerm program to use (UNIX only).

See all Properties

Methods¶

Member	Visibility	Description
CloseInput	public	Close the input stream of the process.
CloseOutput	public	Close the output stream of the process.
CloseStderr	public	Close the error stream of the process.
Create	public	Create a new instance of the TProcess class.
Destroy	public	Destroy this instance of TProcess.
Execute	public	Execute the program with the given options.
ReadInputStream	public	Read available data from input stream.
Resume	public	Resume execution of a suspended process.
RunCommandLoop	public	Execute command and collect output in strings.
Suspend	public	Suspend a running process.
Terminate	public	Terminate a running process.
WaitOnExit	public	Wait for the program to stop executing.

See all Methods

Events¶

Member	Visibility	Description
OnForkEvent	public	Event triggered after fork occurred on Linux.
OnRunCommandEvent	public	Event handler, called when RunCommandLoop is executing.

See all Events