Process Service | Qbs Manual
Description: Allows you to start external processes.

- Qbs Manual
- List of Built-in Services
- Process Service
- Qbs 3.1.1

# Process Service

The `Process` service allows you to start processes, track their output, and so on.

## Available Operations

### Constructor

     Process()

Allocates and returns a new Process object.

### close

     close(): void

Frees the resources associated with the process. It is recommended to always call this function as soon as you are finished with the process.

### closeWriteChannel

     closeWriteChannel(): void

Schedules the stdin channel of process to be closed. The channel will close once all data has been written to the process. After calling this function, any attempts to write to the process will do nothing. See `QProcess::closeWriteChannel()` for more details.

### errorString

     errorString(): string

Returns a human-readable description of the last error that occurred with the process. This can be useful when `start()` or `exec()` fails, to provide more detailed information about the reason (for example, "No such file or directory"). See `QIODevice::errorString()` for more details.

### exec

     exec(filePath: string, arguments: string[], throwOnError: boolean): number

Executes the program at `filePath` with the given argument list and blocks until the process is finished. If an error occurs (for example, there is no executable file at `filePath`) and `throwOnError` is true, then a JavaScript exception will be thrown. Otherwise (the default), -1 will be returned in case of an error. The normal return code is the exit code of the process.

### exitCode

     exitCode(): number

Returns the exit code of the process. This is needed for retrieving the exit code from processes started via `start()`, rather than `exec()`.

### getEnv

     getEnv(varName: string): string

Returns the value of the variable `varName` in the process' environment.

### kill

     kill(): void

Kills the process, causing it to exit immediately.

### readLine

     readLine(): string

Reads and returns one line of text from the process output, without the newline character(s).

### atEnd

     atEnd(): boolean

Returns true if there is no more data to be read from the process output, otherwise returns false.

### readStdErr

     readStdErr(): string

Reads and returns all data from the process' standard error channel.

### readStdOut

     readStdOut(): string

Reads and returns all data from the process' standard output channel.

### setCodec

     setCodec(codec)

Sets the text codec to `codec`. The codec is used for reading and writing from and to the process, respectively. The supported codecs are the same as for `QTextCodec`, for example: "UTF-8", "UTF-16", and "ISO 8859-1".

### setEnv

     setEnv(varName: string, varValue: string): string

Sets the value of variable `varName` to `varValue` in the process environment. This only has an effect if called before the process is started.

### setWorkingDirectory

     setWorkingDirectory(path: string): void

Sets the directory the process will be started in. This only has an effect if called before the process is started.

### start

     start(filePath: string, arguments: string[]): boolean

Starts the program at `filePath` with the given list of arguments. Returns `true` if the process could be started and `false` otherwise.

Note: This call returns right after starting the process and should be used only if you need to interact with the process while it is running. Most of the time, you want to use `exec()` instead.

### terminate

     terminate(): void

Tries to terminate the process. This is not guaranteed to make the process exit immediately; if you need that, use `kill()`.

### waitForFinished

     waitForFinished(timeout: number): boolean

Blocks until the process has finished or `timeout` milliseconds have passed (default is 30000). Returns true if the process has finished and false if the operation has timed out. Calling this function only makes sense for processes started via `start()` (as opposed to `exec()`).

### workingDirectory

     workingDirectory(): string

Returns the directory the process will be started in.

### write

     write(data: string): void

Writes `data` into the process' input channel.

### writeLine

     writeLine(data: string): void

Writes `data`, followed by the newline character(s), into the process' input channel.