Write in brief on UNIX file structure.
UNIX considers every file to be a sequence of 8-bit bytes no interpretation of these bits is made by the operating system. This system provides for maximum flexibility except little support. Every application program must include its own code to interpret an input file into the appropriate structure. Though all operating system should support at least one structure that of an executable file so that the system can load and run programs. A File contains two parts
1. resource fork
2. data fork
Resource fork enclose information of interest to the user. For example it holds the labels of any of the buttons displayed by the program. The data fork contains program data or code the traditional file contents. In UNIX if a user needs to relabel these buttons in his own language the programmer would require changing and recompiling the source code unless the programmer created his own user-changeable data file.