Joys of Programming » log4cpp programming

How to direct logs to multiple log files (destinations) – log4cpp

Joys of Programming — Fri, 15 Jan 2010 14:23:54 +0000

log4cpp can not only be used to log the events to a log file or standard output, but also helps you to log events to multiple destinations. For this purpose, either you can add multiple appenders to a single category or make use of multiple Categories. We will explore the first options. With this option, [...]

log4cpp ConfigureFailure

Joys of Programming — Thu, 14 Jan 2010 07:05:56 +0000

log4cpp programs can be configured using configuration files. But while using log4cpp configurations, you may come across various errors. These can be tracked using log4cpp::ConfigureFailure. See the following program how the missing file error is caught. Suppose that /home/user/conf doesn’t exist. You will get the following excetion

log4cpp: Logging Events and Priorities

Joys of Programming — Thu, 14 Jan 2010 06:50:42 +0000

The most important aspect of a log message is its priority. Take a simple scenario, when you are debugging your program, you want to display all the logs in your program. At that moment, you are not concerned about the resource crunch and performance impact. But when your program is running, you do not want [...]

log4cpp Category

Joys of Programming — Thu, 14 Jan 2010 06:44:50 +0000

Every log message has a priority. But depending on the scenario we decide whether we need to log a message or not. Like every message has a priority, similarly every scenario has a priority. We have the following priorities arranged in the descending order. EMERG, FATAL ALERT CRIT ERROR WARN NOTICE INFO DEBUG NOTSET (no [...]

log4cpp::PropertyConfigurator – Configure with configuration files

Joys of Programming — Thu, 14 Jan 2010 06:42:21 +0000

log4cpp can also be configured with the configuration files. log4cpp::PropertyConfigurator can be used for this purpose. It has a single function which takes as input the configuration file. Simply specify the configuration in a file. You must specify the layout, priority and the appender in the configuration file as shown here You can read here [...]

Create your own Log format with log4cpp::PatternLayout

Joys of Programming — Thu, 14 Jan 2010 06:36:35 +0000

log4cpp::PatternLayout supports four different patterns of log format. But it also supports user specified format. For this purpose, it gives certain format chracters. Some of them are %d: Date %m: log message %n: line separator %p: priority For more such characters refer PatternLayout. The additional benefit of using a format of your own is that [...]

How to install log4cpp from sources?

Joys of Programming — Thu, 14 Jan 2010 06:03:15 +0000

log4cpp is used for logging purposes in C++. To install log4cpp in Linux is as simple as installing some simple packages like liblog4cpp5 and liblog4cpp5-dev. But if you want to install log4cpp from sources, you need to follow the following procedures. Using these steps, you can easily install log4cpp in Mac and Linux (or any [...]

How to Compile and link log4cpp programs?

Joys of Programming — Thu, 14 Jan 2010 05:57:33 +0000

log4cpp, used for logging in C++ can be installed from packages or from the source code. But while programming with log4cpp, you must be aware of certain aspects like the location of the log4cpp headers and log4cpp library. The simplest way to find out the location of the headers The next important thing is to [...]

log4cpp::BasicLayout – Log Format with Additional Information

Joys of Programming — Wed, 13 Jan 2010 14:14:49 +0000

The Log4cpp SimpleLayout is the simplest log layout with the format “priority message”. But for regular usage, you need more information especially information like the timestamp. log4cpp::BasicLayout has the following Layout timeStamp priority category ndc: message where timestamp corresponds to the timestamp when the message was generated, priority corresponds to the type of the logging [...]

Three Important Steps for Log4cpp Programming

Joys of Programming — Tue, 12 Jan 2010 14:18:48 +0000

When you start working with log4cpp, you need to take care of the following steps Initializing an Appender Deciding on the Layout Finalize on the Category Let’s see what each of these mean. Appender: Appender in log4cpp corresponds to the destination of logs. A suitable appender is initialized based on your requirements. The destination of [...]