Chapter 4. The /usr Hierarchy

Table of Contents

4.1. Purpose
4.2. Requirements
4.3. Specific Options
4.4. /usr/bin : Most user commands
4.4.1. Purpose
4.4.2. Requirements
4.4.3. Specific Options
4.5. /usr/include : Directory for standard include files.
4.5.1. Purpose
4.5.2. Specific Options
4.6. /usr/lib : Libraries for programming and packages
4.6.1. Purpose
4.6.2. Specific Options
4.7. /usr/libexec : Binaries run by other programs (optional)
4.7.1. Purpose
4.8. /usr/lib<qual> : Alternate format libraries (optional)
4.8.1. Purpose
4.9. /usr/local : Local hierarchy
4.9.1. Purpose
4.9.2. Requirements
4.9.3. Specific Options
4.9.4. /usr/local/share : Local architecture-independent hierarchy
4.10. /usr/sbin : Non-essential standard system binaries
4.10.1. Purpose
4.10.2. Requirements
4.11. /usr/share : Architecture-independent data
4.11.1. Purpose
4.11.2. Requirements
4.11.3. Specific Options
4.11.4. /usr/share/color : Color management information (optional)
4.11.5. /usr/share/dict : Word lists (optional)
4.11.6. /usr/share/man : Manual pages
4.11.7. /usr/share/misc : Miscellaneous architecture-independent data
4.11.8. /usr/share/ppd : Printer definitions (optional)
4.11.9. /usr/share/sgml : SGML data (optional)
4.11.10. /usr/share/xml : XML data (optional)
4.12. /usr/src : Source code (optional)
4.12.1. Purpose

4.1. Purpose

/usr is the second major section of the filesystem. /usr is shareable, read-only data. That means that /usr should be shareable between various FHS-compliant hosts and must not be written to. Any information that is host-specific or varies with time is stored elsewhere.

Large software packages must not use a direct subdirectory under the /usr hierarchy.