Shell Activity
The Shell activity enables the execution of shell scripts and system commands within a workflow. It provides comprehensive control over command arguments, environment variables, and execution flow management to integrate external processes.
| Field | Description | Requirement |
|---|---|---|
| Command | The specific shell command or script to be executed. | Required |
| Argument 1 | The first argument passed to the shell command. | Optional |
| Argument 2 | The second argument passed to the shell command. | Optional |
| Argument 3 | The third argument passed to the shell command. | Optional |
| Argument 4 | The fourth argument passed to the shell command. | Optional |
| Argument 5 | The fifth argument passed to the shell command. | Optional |
| Wait | Determines if the activity waits for the shell process to terminate before proceeding. | Optional |
| Output Variables | The variable designated to store the standard output of the shell command. | Optional |
| Error Code Variable | The variable designated to store the exit or error code of the shell command. | Optional |
| Redirect Error | Specifies if the standard error should be merged into the standard output stream. | Optional |
| Clean Env | Specifies whether the shell process inherits the current environment variables. | Optional |
| Directory | Defines the default working directory for the shell process. | Optional |
| Exclusive | Ensures that jobs are executed in a specific order when receiving tasks from specific processes. | Optional |
| Execution listeners | Configures listeners for activity, process, sequence flow, or event lifecycle stages. | Optional |
| Multi-instance type | Defines whether and how multiple instances of this activity are generated. | Optional |
| Cardinality (Multi-instance) | A numeric value or expression that sets the number of instances to create. | Optional |
| Collection (Multi-instance) | A collection of elements that determines the number of instances created. | Optional |
| Element Variable (Multi-instance) | The variable name assigned to the current element within a multi-instance loop. | Optional |
| Completion Condition (Multi-instance) | An expression that terminates the creation of new instances when evaluated as true. | Optional |
| Is for compensation | A flag indicating if the activity is used for compensation logic. | Optional |
Action Types & Examples
Execution Listeners
- Format: string
- Example Result: "Start"
Multi-instance Type
- Format: string
- Example Result: "Parallel"
Completion Condition
- Format: boolean expression
- Example Result: "${variable==True}"
Implementation Examples
Field Setup - Command: "sh" - Argument 1: "backup_script.sh" - Directory: "/home/user/scripts" - Output Variables: "cmdOutput"
Execution Parameters - Multi-instance type: "Sequential" - Cardinality (Multi-instance): "2" - Element Variable (Multi-instance): "elementvar" - Execution listeners: "End"
Technical Notes
The Shell activity is designed for high-performance script execution. When utilizing Multi-instance types, ensure that the Cardinality or Collection parameters are correctly defined to prevent execution errors. Standard error redirection is recommended for debugging complex shell scripts to ensure all diagnostic data is captured in the output variable.