A unified logging system for the reading of historical data.


The OSLog framework allows you to read logs. With the unified logging system, you can build custom debugging and analysis tools to be used alongside Apple tools like Instruments and Console. To learn more about how to create logs, see Logging.


Read Log Entries

class OSLogStore

A set of entries from the unified logging system.

class OSLogEnumerator

An enumerator that can access and list log entries.

Log Entries

class OSLogEntry

A single entry from the unified logging system.

class OSLogEntryActivity

An entry generated by an activity event.

class OSLogEntryBoundary

The metadata that partitions sequences of other entries.

class OSLogEntrySignpost

An entry containing a signpost.

protocol OSLogEntryFromProcess

A protocol that defines subclasses containing metadata about a process.

protocol OSLogEntryWithPayload

A protocol defining subclasses that represent entries made using a handle and a format string.

Entry Data

class OSLogMessageComponent

The message arguments for a particular entry.

class OSLogPosition

A representation of a point in a sequence of entries in the unified logging system.