Console (OS X)
|Stable release||10.9 (536) / February 25, 2014|
|Operating system||Mac OS X|
Console is a log viewer developed by Apple Inc. and included with OS X. It allows users to search through all of the system's logged messages, and can alert the user when certain types of messages are logged. The Console is generally used for troubleshooting when there is a problem with the computer. OS X itself, as well as any applications that are used, send a constant stream of messages to the system in the form of log files. The console allows you to read the system logs, help find certain ones, monitor them, and filter their contents.
- 1 Log List
- 2 References
Clicking on "Show Log List" in the toolbar will bring up the Log List. The Log List opens a sidebar which shows all of the different logs that the system maintains. This list helps in viewing the many different logs maintained in various parts of the system by bringing them all together to one place. By clicking on a particular log category, all of the logs will be shown.
System Log Queries
Selecting All Messages gives a live look at your computer's activities, updated live. This includes all activities from both the system as well as any applications running. Logs in this section of the Console are all formatted uniformly. They all include a [Timestamp], the name of the process or application, and the actual message of the log. When the message displayed includes a paperclip icon next to it, it means that it is a shortened version of a longer report, and clicking the icon will show the complete report.
In addition to viewing all messages, user's can also create custom queries with any criteria that they like. These custom queries will filter the messages and will also be shown in the All Messages section. In order to make a new query, choose "New System Log Query" from the File menu. 
Diagnostic and usage information
Logs in this section include diagnostic events by either an application or the user. Diagnostic events include:
- An application quitting unexpectedly.
- The user chooses to force an application to quit.
- A system error requires the user to restart the computer.
Diagnostic and Usage Messages
Messages in this section of the console mainly tell how the system or applications are used. The section contains only the messages, not the actual reports of the problem. While the system log shows ongoing activities of the system, the Diagnostic and Usage Messages section contains information about system hangs and application crashes. 
User Diagnostic Reports
User Diagnostic Reports are messages that relate to the current user's account. Messages from programs that are running while they are logged in will be displayed in this section. 
System Diagnostic Reports
System diagnostic reports include the following information:
- Details about an application or the system not responding.
- An application unexpectedly quitting.
- Kernel Panics
- Information regarding events on the computer (Such as unsuccessful attempts of a function)
- Usage information (How the user uses the system as well as third party software).
Files are used to separate the log files into different categories for easier viewing. While all of the logs can be seen in the all messages section, logs in this section are organized based on the different criteria, and are also linked to the actual files. Therefore, in this section, a user can locate the log file they are looking in a finder window. 
Logs found in this section all relate to drivers and kernel extensions that load when you boot. System.log may also contain drivers and software that are not used any longer, but have lingering services still running. Many times, hardware failures are the cause of drivers, and the log files for those can be found here as well. Most of the logs contained here are from events that occur when the system goes to sleep, shutdowns, restarts, or starts back up.
Logs found in this section are the result of the software communicating with the hardware. When a problem occurs in the translation of commands from the system or an application to the cpu and other electric components of a computer, the log that gets created is stored here.
The logs contained under these folders track the activity in the account of the current user who is logged in. By expanding the folder, you can find logs for specific programs and services within your account. Crash reporter logs are also located in this section. They contain information about applications when they crash, and they can be sent to developers in order to figure out the cause of a crash.
The logs contained here offer the same ability to expand folders and find logs for specific programs and services, however, they are the logs for anyone who uses the computer. This section contains the log files for both the user currently using the computer, as well as for any other accounts on the computer.
Logs in this section are mainly low level logs that do not contain information about any particular application or any specific part of the system. They contain authorization logs for using the system and various applications.