Installation guide

different hardware platforms, different operating systems, and different
programming environments. On DIGITAL UNIX systems, the _ _STDC_ _
symbol is defined as follows:
• When you use the −std0 option, the _ _STDC_ _ symbol is undefined.
(The −std0 option compiles code as defined by Kernighan and Ritchie
(K&R) C.)
• When you use the −std option, the _ _STDC_ _ symbol is 0. (The std
option compiles code as specified by the ANSI C standard. This option
also allows some extensions to the ANSI C standard.)
• When you use the −std1 option, the _ _STDC_ _ symbol is 1. (The
−std1 option compiles code strictly according to the ANSI C standard.)
The predefined symbols on DIGITAL UNIX systems have different names
from their equivalents on ULTRIX systems. Table 7–2 compares the
DIGITAL UNIX and ULTRIX predefined symbols. If you use these symbols
in your application, you must modify the symbol name in your source file
before you recompile your application.
Migrating Your ULTRIX Application to a DIGITAL UNIX System 7–21