iOS and Android Device Logs

iOS和Android设备日志

Complete guide to viewing and filtering device logs on iOS and Android.

Capacitor应用在iOS和Android平台查看与过滤设备日志的完整指南。

When to Use This Skill

使用场景

User needs to see device logs
User is debugging crashes
User wants to filter logs by app
User needs real-time log streaming
User asks "how to see logs"

用户需要查看设备日志
用户正在调试崩溃问题
用户希望按应用过滤日志
用户需要实时日志流
用户询问“如何查看日志”

Quick Commands

快速命令

bash

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bash

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iOS - Stream logs from connected device

iOS - 从已连接设备流式传输日志

xcrun devicectl device log stream --device <UUID>

iOS - Stream from simulator

iOS - 从模拟器流式传输日志

xcrun simctl spawn booted log stream

Android - Stream all logs

Android - 流式传输所有日志

adb logcat

Android - Filter by package

Android - 按应用包名过滤

adb logcat --pid=$(adb shell pidof com.yourapp.id)

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adb logcat --pid=$(adb shell pidof com.yourapp.id)

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iOS Logs

iOS日志

Method 1: Console.app (GUI)

方法1：Console.app（图形界面）

Open Console.app (Applications > Utilities)
Select your device in sidebar
Click "Start Streaming"
Use search to filter:
- By process:
```
process:YourApp
```
- By subsystem:
```
subsystem:com.yourapp
```
- By message:
```
"error"
```

打开Console.app（应用程序 > 实用工具）
在侧边栏选择你的设备
点击“开始流式传输”
使用搜索功能过滤日志：
- 按进程：
```
process:YourApp
```
- 按子系统：
```
subsystem:com.yourapp
```
- 按消息内容：
```
"error"
```

Method 2: devicectl (CLI - Recommended)

方法2：devicectl（命令行工具 - 推荐）

bash

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bash

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List connected devices

列出已连接设备

xcrun devicectl list devices

Stream logs from specific device

从指定设备流式传输日志

xcrun devicectl device log stream --device <DEVICE_UUID>

Stream with predicate filter

使用谓词过滤日志

xcrun devicectl device log stream --device <DEVICE_UUID>
--predicate 'process == "YourApp"'

Stream specific log levels

流式传输指定级别的日志

xcrun devicectl device log stream --device <DEVICE_UUID>
--level error

Save to file

将日志保存到文件

xcrun devicectl device log stream --device <DEVICE_UUID>
--predicate 'process == "YourApp"' > app_logs.txt

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xcrun devicectl device log stream --device <DEVICE_UUID>
--predicate 'process == "YourApp"' > app_logs.txt

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Method 3: simctl for Simulators

方法3：使用simctl查看模拟器日志

bash

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bash

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Stream logs from booted simulator

从已启动的模拟器流式传输日志

xcrun simctl spawn booted log stream

Filter by process

按进程过滤

xcrun simctl spawn booted log stream --predicate 'process == "YourApp"'

Filter by subsystem

按子系统过滤

xcrun simctl spawn booted log stream --predicate 'subsystem == "com.yourapp"'

Show only errors

仅显示错误日志

xcrun simctl spawn booted log stream --level error

Combine filters

组合过滤条件

xcrun simctl spawn booted log stream
--predicate 'process == "YourApp" AND messageType == error'

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xcrun simctl spawn booted log stream
--predicate 'process == "YourApp" AND messageType == error'

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Method 4: Xcode Device Logs

方法4：Xcode设备日志

Window > Devices and Simulators
Select device
Click "Open Console"
Or: View device logs for crash reports

窗口 > 设备与模拟器
选择设备
点击“打开控制台”
或者：查看设备日志中的崩溃报告

iOS Log Predicate Examples

iOS日志谓词示例

bash

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bash

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Process name

按进程名称

--predicate 'process == "YourApp"'

Contains text

包含指定文本

--predicate 'eventMessage contains "error"'

Subsystem

按子系统

--predicate 'subsystem == "com.yourapp.plugin"'

按分类

--predicate 'category == "network"'

Log level

按日志级别

--predicate 'messageType == error'

Combined

组合条件

--predicate 'process == "YourApp" AND messageType >= error'

Time-based (last 5 minutes)

时间范围（最近5分钟）

--predicate 'timestamp > now - 5m'

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--predicate 'timestamp > now - 5m'

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iOS Log Levels

iOS日志级别

Level	Description
`default`	Default messages
`info`	Informational
`debug`	Debug (hidden by default)
`error`	Error conditions
`fault`	Fault/critical

级别	描述
`default`	默认消息
`info`	信息性消息
`debug`	调试信息（默认隐藏）
`error`	错误情况
`fault`	严重错误/故障

Android Logs

Android日志

Method 1: adb logcat (CLI)

方法1：adb logcat（命令行工具）

bash

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bash

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Basic log stream

基础日志流

adb logcat

Clear logs first, then stream

先清空日志，再开始流式传输

adb logcat -c && adb logcat

Filter by tag

按标签过滤

adb logcat -s MyTag:D

Filter by priority

按优先级过滤

adb logcat *:E # Only errors and above

adb logcat *:E # 仅显示错误及以上级别

Filter by package name

按包名过滤

adb logcat --pid=$(adb shell pidof com.yourapp.id)

Filter by multiple tags

按多个标签过滤

adb logcat -s "MyPlugin:D" "Capacitor:I"

Save to file

将日志保存到文件

adb logcat > logs.txt

Save to file with timestamp

带时间戳保存到文件

adb logcat -v time > logs.txt

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adb logcat -v time > logs.txt

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Method 2: Android Studio Logcat (GUI)

方法2：Android Studio Logcat（图形界面）

View > Tool Windows > Logcat

Use filter dropdown:

Package:
```
package:com.yourapp
```
Tag:
```
tag:MyPlugin
```
Level:
```
level:error
```

Create saved filters for quick access

视图 > 工具窗口 > Logcat
使用过滤下拉菜单：
- 包名：
```
package:com.yourapp
```
- 标签：
```
tag:MyPlugin
```
- 级别：
```
level:error
```
创建保存的过滤条件以便快速访问

Method 3: pidcat (Better CLI Tool)

方法3：pidcat（更优命令行工具）

bash

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bash

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Install pidcat

安装pidcat

pip install pidcat

Stream logs for package

流式传输指定包名的日志

pidcat com.yourapp.id

With tag filter

带标签过滤

pidcat -t MyPlugin com.yourapp.id

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pidcat -t MyPlugin com.yourapp.id

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Android Log Priority Levels

Android日志优先级级别

Letter	Priority
V	Verbose
D	Debug
I	Info
W	Warn
E	Error
F	Fatal
S	Silent

字母	优先级
V	详细（Verbose）
D	调试（Debug）
I	信息（Info）
W	警告（Warn）
E	错误（Error）
F	致命（Fatal）
S	静默（Silent）

adb logcat Format Options

adb logcat格式选项

bash

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bash

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Different output formats

不同输出格式

adb logcat -v brief # Default adb logcat -v process # PID only adb logcat -v tag # Tag only adb logcat -v time # With timestamp adb logcat -v threadtime # With thread and time adb logcat -v long # All metadata

adb logcat -v brief # 默认格式 adb logcat -v process # 仅显示进程ID adb logcat -v tag # 仅显示标签 adb logcat -v time # 带时间戳 adb logcat -v threadtime # 带线程和时间信息 adb logcat -v long # 显示所有元数据

Colorized output

彩色输出

adb logcat -v color

Show recent logs (last N lines)

显示最近N条日志

adb logcat -d -t 100

Show logs since timestamp

显示指定时间戳之后的日志

adb logcat -v time -T "01-25 10:00:00.000"

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adb logcat -v time -T "01-25 10:00:00.000"

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Common Android Filters

常见Android过滤规则

bash

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bash

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Capacitor core logs

Capacitor核心日志

adb logcat -s "Capacitor:*"

Plugin-specific logs

插件专属日志

adb logcat -s "CapacitorNativeBiometric:*"

WebView logs (JavaScript console)

WebView日志（JavaScript控制台）

adb logcat -s "chromium:*"

JavaScript errors

JavaScript错误

adb logcat | grep -i "js error|uncaught"

Crash logs

崩溃日志

adb logcat | grep -iE "fatal|crash|exception"

Network logs

网络日志

adb logcat -s "OkHttp:" "NetworkSecurityConfig:"

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adb logcat -s "OkHttp:" "NetworkSecurityConfig:"

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Viewing Crash Logs

查看崩溃日志

iOS Crash Logs

iOS崩溃日志

bash

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bash

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Copy crash logs from device

从设备复制崩溃日志

xcrun devicectl device copy crashlog --device <UUID> ./crashes/

View in Console.app

在Console.app中查看

User Diagnostics Reports section

用户诊断报告板块

Or find at:

或者在以下位置查找：

Device: Settings > Privacy > Analytics & Improvements > Analytics Data

设备：设置 > 隐私与安全性 > 分析与改进 > 分析数据

Mac: ~/Library/Logs/DiagnosticReports/

Mac：~/Library/Logs/DiagnosticReports/

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Android Crash Logs

Android崩溃日志

bash

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bash

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Get tombstone (native crash)

获取tombstone（原生崩溃日志）

adb shell cat /data/tombstones/tombstone_00

Get ANR traces

获取ANR跟踪日志

adb pull /data/anr/traces.txt

Get bugreport (comprehensive)

获取完整bug报告

adb bugreport > bugreport.zip

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adb bugreport > bugreport.zip

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MCP Integration

MCP集成

Use MCP tools to fetch logs programmatically:

typescript

// Example MCP tool for fetching iOS logs
const logs = await mcp.ios.streamLogs({
  device: 'booted',
  predicate: 'process == "YourApp"',
  level: 'debug',
});

// Example MCP tool for Android logs
const androidLogs = await mcp.android.logcat({
  package: 'com.yourapp.id',
  level: 'D',
});

使用MCP工具以编程方式获取日志：

typescript

// 示例：获取iOS日志的MCP工具
const logs = await mcp.ios.streamLogs({
  device: 'booted',
  predicate: 'process == "YourApp"',
  level: 'debug',
});

// 示例：获取Android日志的MCP工具
const androidLogs = await mcp.android.logcat({
  package: 'com.yourapp.id',
  level: 'D',
});

Log Parsing Tips

日志解析技巧

Extract JavaScript Errors

提取JavaScript错误

bash

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bash

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iOS - JavaScript console logs

iOS - JavaScript控制台日志

xcrun simctl spawn booted log stream
--predicate 'eventMessage contains "JS:"'

Android - WebView console

Android - WebView控制台日志

adb logcat chromium:I *:S | grep "console"

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adb logcat chromium:I *:S | grep "console"

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Filter Network Requests

过滤网络请求日志

bash

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bash

undefined

iOS

xcrun simctl spawn booted log stream
--predicate 'subsystem == "com.apple.network"'

Android

adb logcat -s "NetworkSecurityConfig:" "OkHttp:"

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adb logcat -s "NetworkSecurityConfig:" "OkHttp:"

undefined

Monitor Memory

监控内存

bash

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bash

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iOS - Memory pressure

iOS - 内存压力

xcrun simctl spawn booted log stream
--predicate 'eventMessage contains "memory"'

Android - Memory info

Android - 内存信息

adb shell dumpsys meminfo com.yourapp.id

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adb shell dumpsys meminfo com.yourapp.id

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Troubleshooting

常见问题排查

Issue: No Logs Showing

问题：无日志显示

iOS:

Ensure device is trusted: Xcode > Window > Devices
Try restarting log stream
Check Console.app filters

Android:

Enable USB debugging
Run
```
adb devices
```
to verify connection
Try
```
adb kill-server && adb start-server
```

iOS:

确保设备已信任：Xcode > 窗口 > 设备
尝试重启日志流
检查Console.app的过滤条件

Android:

启用USB调试
运行
```
adb devices
```
验证设备连接
尝试
```
adb kill-server && adb start-server
```

Issue: Too Many Logs

问题：日志过多

Use filters:

bash

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使用过滤条件：

bash

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iOS - Only your app

iOS - 仅显示你的应用日志

--predicate 'process == "YourApp" AND messageType >= info'

Android - Only your package

Android - 仅显示指定包名的日志

adb logcat --pid=$(adb shell pidof com.yourapp.id)

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adb logcat --pid=$(adb shell pidof com.yourapp.id)

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Issue: Missing Debug Logs

问题：缺少调试日志

iOS: Debug logs are hidden by default

bash

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iOS：调试日志默认隐藏

bash

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Enable debug logs

启用调试日志

xcrun simctl spawn booted log stream --level debug


**Android**: Ensure log level is set correctly
```kotlin
Log.d("Tag", "Debug message")  // D level

xcrun simctl spawn booted log stream --level debug


**Android**：确保日志级别设置正确
```kotlin
Log.d("Tag", "Debug message")  // D级别

Best Practices

最佳实践

Use structured logging - Include context in log messages
Add timestamps - Helps correlate events
Filter early - Don't stream all logs
Save important logs - Redirect to file for later analysis
Use log levels appropriately - Debug for dev, error for production

使用结构化日志 - 在日志消息中包含上下文信息
添加时间戳 - 有助于关联事件
提前过滤 - 不要流式传输所有日志
保存重要日志 - 重定向到文件以便后续分析
合理使用日志级别 - 调试级别用于开发环境，错误级别用于生产环境

Resources

参考资源

iOS Unified Logging: https://developer.apple.com/documentation/os/logging
Android Logcat: https://developer.android.com/studio/debug/logcat
devicectl Reference: https://developer.apple.com/documentation/devicemanagement

iOS统一日志系统：https://developer.apple.com/documentation/os/logging
Android Logcat：https://developer.android.com/studio/debug/logcat
devicectl参考文档：https://developer.apple.com/documentation/devicemanagement

ios-android-logs

Original

Translation

iOS and Android Device Logs

iOS和Android设备日志

When to Use This Skill

使用场景

Quick Commands

快速命令

iOS - Stream logs from connected device

iOS - 从已连接设备流式传输日志

iOS - Stream from simulator

iOS - 从模拟器流式传输日志

Android - Stream all logs

Android - 流式传输所有日志

Android - Filter by package

Android - 按应用包名过滤

iOS Logs

iOS日志

Method 1: Console.app (GUI)

方法1：Console.app（图形界面）

Method 2: devicectl (CLI - Recommended)

方法2：devicectl（命令行工具 - 推荐）

List connected devices

列出已连接设备

Stream logs from specific device

从指定设备流式传输日志

Stream with predicate filter

使用谓词过滤日志

Stream specific log levels

流式传输指定级别的日志

Save to file

将日志保存到文件

Method 3: simctl for Simulators

方法3：使用simctl查看模拟器日志

Stream logs from booted simulator

从已启动的模拟器流式传输日志

Filter by process

按进程过滤

Filter by subsystem

按子系统过滤

Show only errors

仅显示错误日志

Combine filters

组合过滤条件

Method 4: Xcode Device Logs

方法4：Xcode设备日志

iOS Log Predicate Examples

iOS日志谓词示例

Process name

按进程名称

Contains text

包含指定文本

Subsystem

按子系统

Category

按分类

Log level

按日志级别

Combined

组合条件

Time-based (last 5 minutes)

时间范围（最近5分钟）

iOS Log Levels

iOS日志级别

Android Logs

Android日志

Method 1: adb logcat (CLI)

方法1：adb logcat（命令行工具）

Basic log stream

基础日志流

Clear logs first, then stream

先清空日志，再开始流式传输

Filter by tag

按标签过滤

Filter by priority

按优先级过滤

Filter by package name

按包名过滤

Filter by multiple tags