Ends the background Smalltalk process handling asynchronous I/O.

Creates a process to execute the specified string using the shell specified by CurrentShell in the current environment. Starts the process running and answers the process. If an error occurs starting the process, answers nil.

Creates a process to execute the specified string using the shell specified by CurrentShell and the given environment. Starts the process running and answers the process. If an error occurs starting the process, answers nil. If any of the I/O parameters are not nil, initializes the appropriate stdin, stdout, and stderr pipes.

Invokes a shell specified by CurrentShell that executes the specified string in the current environment. Answers the stdout contents and stderr contents concatenated. If an error occurs starting the process, generates a walkback.

Starts a background Smalltalk process to grab I/O for the active UNIXProcess and moves it between Smalltalk and the operating system.

Invokes a shell that executes the specified string in the current environment. Answers the integer exitCode of the process. If an error occurs starting the process, answers nil. If the UNIX primitive for completion checking fails, generates a walkback.

Closes the specified pipe. Generates a walkback if the pipe is not valid.

Obsolete protocol retained for compatibility. It should be replaced with isComplete

Answers an integer representing the receiver's exitCode. If the process has not completed, answers nil. This is operating-system dependent.

Flushes all data in the pipe from the operating system process associated with the receiver to the Smalltalk UNIXReadPipeStream. Generates a walkback if the specifed pipe stream is not an instance of UNIXReadPipeStream or is not a valid UNIXPipeStream.

Obsolete protocol retained for compatibility. Should be replaced with pid.

Answers true if the receiver process has completed, answers false if not. If the UNIX primitive for completion checking fails, generates a walkback.

Kills the receiver process. Try using the SIGTERM signal first. If the process does not die within 5 seconds, sends the SIGKILL signal. This method blocks until the process dies. Answers the receiver.

Answers the next available character from the receiver's stdout. If the read would block, answers nil. On any other error answers a character with a value of zero.

Writes a character to the receiver's stdin pipe, specified by on:. Generates a walkback if the pipe is not valid. Answers the character.

Answers the integer representing the process id of the receiver's operating system process. If there is no corresponding operating system process, answers nil.

Obsolete protocol retained for compatibility. The execute:input:output:error:environment: message encompasses this behavior.

Answers a UNIXReadPipeStream representing the receiver's stderr pipe, or nil if the pipe is undefined.

Answers a UNIXWritePipeStream representing the receiver's stdin pipe, or nil if the pipe is undefined.

Answers a UNIXReadPipeStream representing the receiver's stdout pipe, or nil if the pipe is undefined.

Ensures the receiver has finished the last operation. Answers the exitCode of the process. This is a blocking operation. If the stdin pipe has not been closed, the operation may block indefinitely.