# hilog HiLog is a log system that provides logging for the system framework, services, and applications to record information on user operations and system running status. You can run the hilog commands to query related log information. ## Prerequisites - The environment for OpenHarmony Device Connector (hdc) has been set up. For details, see [Environment Setup](hdc.md#environment-setup). - The devices are properly connected. ## Commands The table below lists the available **hilog** command line options. | Short Option| Long Option| Parameter| Description| | -------- | -------- | -------- | -------- | | -h | --help | | Shows help information.| | Default| Default| | Performs a blocking read on logs, with no exiting after the read finishes.| | -x | --exit | | Performs a non-blocking read on logs, with exiting after the read finishes.| | -g | | | Checks the buffer size for logs of a specified type. This option is used together with **-t**, which specifies a log type. By default, the **app** or **core** types are used.| | -G | --buffer-size | <size> | Sets the size of the buffer for logs of a specified type. This option is used together with **-t**, which specifies a log type. By default, the **app** or **core** types are used. The unit can be B, KB, MB, or GB. The value ranges from 64 KB to 16 MB.| | -r | | | Clears the buffer for logs of a specified type. This option is used together with **-t**, which specifies a log type. By default, the **app** or **core** types are used.| | -p | --privacy | <on/off> | Specifies whether to enable privacy for logs during system debugging.| | | | on | Enables privacy so that parameters are displayed as **\** in printed logs.| | | | off | Disables privacy so that parameters are displayed as they are in printed logs.| | -k | | <on/off> | Specifies whether to enable kernel logging.| | | | on | Enables kernel logging.| | | | off | Disables kernel logging.| | -s | --statistics | | Shows statistics. This option must be used together with **-t** or **-D**.| | -S | | | Clears statistics. This option must be used together with **-t** or **-D**.| | -Q | | <control-type> | Specifies whether to enable the default quota for flow control.| | | | pidon | Enables process flow control.| | | | pidoff | Disables process flow control.| | | | domainon | Enables domain flow control.| | | | domainoff | Disables domain flow control.| | -L | --level | <level> | Sets the log level, for example, **-L D/I/W/E/F**.| | -t | --type | <type> | Sets the log type, for example, **-t app core init**.| | -D | --domain | <domain> | Sets the domain.| | -T | --tag | <tag> | Sets the tag.| | -a | --head | <n> | Shows the first several lines of logs.The parameter **\** indicates the number of first lines to show.| | -z | --tail | <n> | Shows the last several lines of logs.The parameter **\** indicates the number of last lines to show.| | -P | --pid | <pid> | Identifies a process.| | -e | --regex | <expr> | Prints only the lines of logs that match the regular expression specified through **\**.| | -f | --filename | <filename> | Sets the names of the files to be flushed to disk.| | -l | --length | <length> | Sets the size of the files to be flushed to disk. The value must be greater than or equal to 64 KB.| | -n | --number | <number> | Sets the number of files to be flushed to disk.| | -j | --jobid | <jobid> | Sets the ID of a flushing task.| | -w | --write | <control> | Controls a flushing task.| | | | query | Queries flushing tasks.| | | | start | Starts a flushing task. The command line parameters are the file name, size of a single file, flushing mode, and number of rotated files.| | | | stop | Stops a flushing task.| | | | refresh | Refreshes the logs in the buffer to the flushed file.| | | | clear | Deletes log files that are flushed to disks.| | -m | --stream | <algorithm> | Sets the flushing mode.| | | | none | Indicates that data is flushed to disks in non-compression mode.| | | | zlib | Indicates that data is flushed to disks using the zlib compression algorithm. The flushed file is in .gz format.| | | | zstd | Indicates that data is flushed to disks using the zstd compression algorithm. The flushed file is in .zst format.| | -v | --format | <format> | | | | | time | Displays the local time.| | | | color | Adds colors to logs at different levels. By default, logs are displayed in black and white.| | | | epoch | Displays the amount of time elapsed since the epoch time.| | | | monotonic | Displays the amount of time elapsed since the system startup time.| | | | usec | Displays the time in microseconds.| | | | nsec | Displays the time in nanoseconds.| | | | year | Displays the time with the year portion.| | | | zone | Displays the time with the local time zone.| | -b | --baselevel | <loglevel> | Sets the lowest level of logs that can be printed: D(DEBUG)/I(INFO)/W(WARN)/E(ERROR)/F(FATAL).| ## Examples ### Display the help information. ``` hilog -h ``` **Example** ``` $ hilog -h Usage: -h --help Show all help information. Show single help information with option: query/clear/buffer/stats/persist/private/kmsg/flowcontrol/baselevel/domain/combo Querying logs options: No option performs a blocking read and keeps printing. -x --exit Performs a non-blocking read and exits when all logs in buffer are printed. -a , --head= Show n lines logs on head of buffer. -z , --tail= Show n lines logs on tail of buffer. ``` ### Display the size of the log buffer. ``` hilog -g ``` **Example** ``` $ hilog -g Log type app buffer size is 16.0M Log type init buffer size is 16.0M Log type core buffer size is 16.0M Log type only_prerelease buffer size is 16.0M ``` ### Change the size of the log buffer. ``` hilog -G size ``` **Example** ``` $ hilog -G 16M Set log type app buffer size to 16.0M successfully Set log type init buffer size to 16.0M successfully Set log type core buffer size to 16.0M successfully Set log type only_prerelease buffer size to 16.0M successfully ``` ### Enable/Disable process flow control. ``` hilog -Q pidon/pidoff ``` **Example** ``` $ hilog -Q pidon Set flow control by process to enabled successfully $ $ hilog -Q pidoff Set flow control by process to disabled successfully ``` ### Enable/Disable domain flow control. ``` hilog -Q domainon/domainoff ``` **Example** ``` $ hilog -Q domainon Set flow control by domain to enabled successfully $ $ hilog -Q domainoff Set flow control by domain to disabled successfully ``` ### Display logs of a specified level. ``` hilog -L D/I/W/E/F ``` **Example** ``` $ hilog -L E 08-28 09:01:25.730 2678 2678 E A00F00/com.huawei.hmos.aidataservice/AiDataService_5.10.7.320: DataChangeNotifyManager: notifyDataChange CommonEntity no valid entity to notify 08-28 09:01:56.058 8560 8560 E A00500/com.ohos.settingsdata/SettingsData: DB not ready request = datashare:///com.ohos.settingsdata/entry/settingsdata/SETTINGSDATA?Proxy=true&key=analysis_service_switch_on , retry after DB startup 08-28 09:01:56.082 8560 8560 E A00500/com.ohos.settingsdata/SettingsData: decoder failure: /data/migrate/settings_global.xml , error code:-1 08-28 09:01:56.082 8560 8560 E A00500/com.ohos.settingsdata/SettingsData: clearXml failed:No such file or directory, error code:13900002 08-28 09:01:56.083 8560 8560 E A00500/com.ohos.settingsdata/SettingsData: readText failed:No such file or directory, error code:13900002 08-28 09:01:56.371 8586 8586 E A00500/com.ohos.settingsdata/SettingsData: DB not ready request = datashare:///com.ohos.settingsdata/entry/settingsdata/SETTINGSDATA?Proxy=true&key=photo_network_connection_status , retry after DB startup 08-28 09:01:56.408 8586 8586 E A00500/com.ohos.settingsdata/SettingsData: decoder failure: /data/migrate/settings_global.xml , error code:-1 ``` ### Display logs of a specified tag. ``` hilog -T tag ``` **Example** ``` $ hilog -T SAMGR 08-28 09:27:59.581 610 11504 I C01800/samgr/SAMGR: CommonEventCollect save extraData 1661 08-28 09:27:59.581 610 11504 I C01800/samgr/SAMGR: OnReceiveEvent get action: usual.event.BATTERY_CHANGED code: 0, extraDataId 1661 08-28 09:27:59.582 610 11504 I C01800/samgr/SAMGR: DoEvent:4 name:usual.event.BATTERY_CHANGED value:0 08-28 09:27:59.582 610 11504 W C01800/samgr/SAMGR: LoadSa SA:10120 AddDeath fail,cnt:1,callpid:610 08-28 09:27:59.583 610 11504 I C01800/samgr/SAMGR: LoadSa SA:10120 size:1,count:1 08-28 09:27:59.601 610 11504 I C01800/samgr/SAMGR: Scheduler SA:10120 loading 08-28 09:27:59.965 11518 11518 I C01800/media_analysis_service/SAMGR: SA:10120 OpenSo spend 315ms 08-28 09:27:59.965 610 4064 I C01800/samgr/SAMGR: AddProc:media_analysis_service. size:75 ``` ### Display logs of a specified process. ``` hilog -P pid ``` **Example** ``` $ hilog -P 618 08-28 10:19:16.872 618 17729 I C02D15/hiview/XPower: [task_52]#current system load is: 0.028767 08-28 10:19:23.997 618 17580 I C02D10/hiview/CpuCollector: CalculateProcessCpuStatInfos: startTime=1724811553746, endTime=1724811563996, startBootTime=47001084, endBootTime=47011335, period=10251 08-28 10:19:23.999 618 17580 I C02D10/hiview/CpuCollector: CollectProcessCpuStatInfos: collect process cpu statistics information size=234, isNeedUpdate=1 08-28 10:19:24.002 618 17580 W C01650/hiview/Rdb: DB : 08-28 10:19:24.002 618 17580 W C01650/hiview/Rdb: device: 12583051 inode: 40230 mode: 432 size: 569344 natime: Wed Aug 28 00:00:06 2024 08-28 10:19:24.002 618 17580 W C01650/hiview/Rdb: smtime: Wed Aug 28 00:34:30 2024 08-28 10:19:24.002 618 17580 W C01650/hiview/Rdb: sctime: Wed Aug 28 00:34:30 2024 ``` ### Display and set flushing tasks ``` hilog -w control ``` > **NOTE** > > Run **hilog -w query** to query the current task. > > Run **hilog -w start -n 1000** to start the HiLog flushing task and set the number of flushed files to **1000**. > > Run **hilog -w start -n 100 -t kmsg** to start the kmsglog flushing task and set the number of flushed files to **100**. > > Run hilog -w stop to stop the flushing task. **Example** ``` $ hilog -w query Persist task query failed No running persistent task [CODE: -63] $ $ hilog -w start -n 1000 Persist task [jobid:1][fileNum:1000][fileSize:4194304] start successfully $ $ hilog -w start -n 100 -t kmsg Persist task [jobid:2][fileNum:100][fileSize:4194304] start successfully $ $ hilog -w stop Persist task [jobid:1] stop successfully Persist task [jobid:2] stop successfully ``` ### Set the lowest level of logs that can be printed ``` hilog -b D/I/W/E/F ``` **Example** ``` $ hilog -b E Set global log level to E successfully ``` ### Enable/Disable the privacy format. ``` hilog -p on/off ``` **Example** ``` # hilog -p on Set hilog privacy format on successfully # # hilog -p off Set hilog privacy format off successfully ```