UNIX Filesystems: Evolution, Design, and Implementation

UNIX Standardization

The section A Brief Walk through Time earlier in the chapter showed how the different versions of UNIX came into existence through the 1980s. Although most of these versions stemmed from either System V or BSD, each OS vendor added its own enhancements, whether to increase performance or add new interfaces in response to internal or customer demands. Because application portability was crucial to the success of application developers, it soon became clear that a level of standardization was needed to prevent this divergence from going too far.

Various bodies have been responsible for driving the standardization of UNIX interfaces, whether at a command level, library, or system call level; or newer initiatives such as the Large File Summit for 64-bit file access and the Data Management Interfaces Group (DMIG) for interfaces relating to Hierarchical Storage Management. This section describes the main standards bodies, their goals, and the standards that they have produced.

IEEE and POSIX

The /usr/group organization was formed by a group of individuals in 1980 with the intention of standardizing user-level interfaces with the goal of application portability.

They reached consensus in 1984, and their work was used by the ANSI X3J11 committee, the same group who were working on standardization of the C language. As the number of versions of UNIX started to increase, divergence continued, and the /usr/group standard became less and less effective. This led to the ...