@ohos.process (Obtaining Process Information)
The process module provides process management APIs, for example, APIs for obtaining process information.
NOTE
The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
Modules to Import
import { process } from '@kit.ArkTS';
Properties
System capability: SystemCapability.Utils.Lang
Atomic service API: This API can be used in atomic services since API version 11.
| Name | Type | Read-Only | Optional | Description |
|---|---|---|---|---|
| uid | number | Yes | No | User identifier (UID) of the process. |
| pid | number | Yes | No | Process ID (PID) of the process. |
| tid8+ | number | Yes | No | Thread ID (TID) of the thread. |
EventListener
type EventListener = (evt: Object) => void
Event to store.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| evt | Object | Yes | Event. |
process.isIsolatedProcess8+
isIsolatedProcess(): boolean
Checks whether this process is isolated.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if the process is isolated; otherwise, false is returned. |
Example
let result = process.isIsolatedProcess();
process.is64Bit8+
is64Bit(): boolean
Checks whether this process is running in a 64-bit environment.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if the process is running in a 64-bit environment; otherwise, false is returned. |
Example
let result = process.is64Bit();
process.getStartRealtime8+
getStartRealtime(): number
Obtains the duration (excluding the system sleep time), in milliseconds, from the time the system starts to the time the process starts.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| number | Duration obtained, in milliseconds. |
Example
let realtime = process.getStartRealtime();
process.getPastCpuTime8+
getPastCpuTime(): number
Obtains the CPU time (in milliseconds) from the time the process starts to the current time.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| number | CPU time obtained, in milliseconds. |
Example
let result = process.getPastCpuTime();
process.abort
abort(): void
Aborts a process and generates a core file. This method will cause a process to exit immediately. Exercise caution when using this method.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Example
process.abort();
process.uptime
uptime(): number
Obtains the running time of the current system, in seconds.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Return value
| Type | Description |
|---|---|
| number | Running time of the system, in seconds. |
Example
let time = process.uptime();
process.kill(deprecated)
kill(signal: number, pid: number): boolean
Sends a signal to a specified process to terminate it.
NOTE
This API is supported since API version 7 and deprecated since API version 9. You are advised to use kill9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| signal | number | Yes | Signal to send. |
| pid | number | Yes | PID of the process, to which the signal will be sent. |
Return value
| Type | Description |
|---|---|
| boolean | If the signal is sent successfully, true is returned. Other, false is returned. |
Example
let pres = process.pid;
let result = process.kill(28, pres);
process.exit(deprecated)
exit(code: number): void
Terminates this process.
Exercise caution when using this API. After this API is called, the application exits. If the input parameter is not 0, data loss or exceptions may occur.
NOTE
This API is supported since API version 7 and deprecated since API version 9. You are advised to use exit9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| code | number | Yes | Exit code of the process. |
Example
process.exit(0);
process.getUidForName(deprecated)
getUidForName(v: string): number
Obtains the UID of a user from the user database of the system based on the specified user name.
NOTE
This API is supported since API version 8 and deprecated since API version 9. You are advised to use getUidForName9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | string | Yes | User name. |
Return value
| Type | Description |
|---|---|
| number | UID of the user. |
Example
let pres = process.getUidForName("tool");
process.getThreadPriority(deprecated)
getThreadPriority(v: number): number
Obtains the thread priority based on the specified TID.
NOTE
This API is supported since API version 8 and deprecated since API version 9. You are advised to use getThreadPriority9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | number | Yes | TID. |
Return value
| Type | Description |
|---|---|
| number | Priority of the thread. The priority depends on the operating system. |
Example
let tid = process.tid;
let pres = process.getThreadPriority(tid);
process.isAppUid(deprecated)
isAppUid(v: number): boolean
Checks whether a UID belongs to this application.
NOTE
This API is supported since API version 8 and deprecated since API version 9. You are advised to use isAppUid9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | number | Yes | UID. |
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if the UID belongs to the application; otherwise, false is returned. |
Example
let result = process.isAppUid(688);
process.getSystemConfig(deprecated)
getSystemConfig(name: number): number
Obtains the system configuration.
NOTE
This API is supported since API version 8 and deprecated since API version 9. You are advised to use getSystemConfig9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| name | number | Yes | System configuration parameter name. |
Return value
| Type | Description |
|---|---|
| number | System configuration obtained. |
Example
let _SC_ARG_MAX = 0;
let pres = process.getSystemConfig(_SC_ARG_MAX);
process.getEnvironmentVar(deprecated)
getEnvironmentVar(name: string): string
Obtains the value of an environment variable.
NOTE
This API is supported since API version 8 and deprecated since API version 9. You are advised to use getEnvironmentVar9+ instead.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| name | string | Yes | Environment variable name. |
Return value
| Type | Description |
|---|---|
| string | Value of the environment variable. |
Example
let pres = process.getEnvironmentVar("PATH");
ProcessManager9+
Provides APIs for throwing exceptions during the addition of a process.
Construct a ProcessManager object.
isAppUid9+
isAppUid(v: number): boolean
Checks whether a UID belongs to this application.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | number | Yes | UID. which can be obtained by running process.uid. |
Return value
| Type | Description |
|---|---|
| boolean | Check result. The value true is returned if the UID belongs to the application; otherwise, false is returned. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
// Use process.uid to obtain the UID.
let pres = process.uid;
let result = pro.isAppUid(pres);
console.info("result: " + result); // result: true
getUidForName9+
getUidForName(v: string): number
Obtains the UID of a user from the user database of the system based on the specified user name.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | string | Yes | User name. |
Return value
| Type | Description |
|---|---|
| number | UID of the user. If the user does not exist, -1 is returned. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
let pres = pro.getUidForName("tool");
getThreadPriority9+
getThreadPriority(v: number): number
Obtains the thread priority based on the specified TID.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| v | number | Yes | TID. |
Return value
| Type | Description |
|---|---|
| number | Priority of the thread. The priority depends on the operating system. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
let tid = process.tid;
let pres = pro.getThreadPriority(tid);
getSystemConfig9+
getSystemConfig(name: number): number
Obtains the system configuration.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| name | number | Yes | System configuration parameter name. |
Return value
| Type | Description |
|---|---|
| number | System configuration obtained. If the configuration does not exist, -1 is returned. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
let _SC_ARG_MAX = 0;
let pres = pro.getSystemConfig(_SC_ARG_MAX);
getEnvironmentVar9+
getEnvironmentVar(name: string): string
Obtains the value of an environment variable.
NOTE
Obtains the value of an environment variable. If the environment variable does not exist, undefined is returned.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| name | string | Yes | Environment variable name. |
Return value
| Type | Description |
|---|---|
| string | Value of the environment variable. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
let pres = pro.getEnvironmentVar("PATH");
exit9+
exit(code: number): void
Terminates this process.
Exercise caution when using this API. After this API is called, the application exits. If the input parameter is not 0, data loss or exceptions may occur.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| code | number | Yes | Exit code of the process. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
pro.exit(0);
kill9+
kill(signal: number, pid: number): boolean
Sends a signal to the specified process to terminate it. Only the current process can be terminated.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| signal | number | Yes | Signal to send. Value range: 1 <= signal <= 64. |
| pid | number | Yes | PID of the process, to which the signal will be sent. |
Return value
| Type | Description |
|---|---|
| boolean | Signal sending result. The value true is returned if the signal is sent successfully; otherwise, false is returned. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1. Mandatory parameters are left unspecified; 2. Incorrect parameter types. |
Example
let pro = new process.ProcessManager();
let pres = process.pid;
let result = pro.kill(28, pres);