For computer log management, the Common Log Format, also known as the NCSA Common log format, (after NCSA HTTPd) is a standardized text file format used by web servers when generating server log files. Because the format is standardized, the files can be readily analyzed by a variety of web analysis programs, for example Webalizer and Analog.
Each line in a file stored in the Common Log Format has the following syntax:
The format is extended by the Combined Log Format with referer and user-agent fields.