Detailed and proper documentation of source code and programs is the milestone of Unix culture, as we may read in “The art of Unix Programming” by Eric Steven Raymond. The first application on Unix was the platform to prepare documents. The platform was used by Bell Labs to prepare patent documents. Effective work with documentation and searching for needed information is the key feature when working on unix-like systems.

1. Local documentation

1.1. man
Usually the first and most basic information source about a given program are man pages. The name stands for the English word manual. Man pages are divided into eight parts:

General Commands
System Calls
Subroutines
Special Files
File Formats
Games
Macros and Conventions
Maintenance Commands

Each page is divided into the following sections:

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