Apue Study Notes-Chapter 2. UNIX standardization and Implementations

1. UNIX standards

1.1 Iso c 1.2 POSIX (poratble operationg system interface) POSIX includes standards in Iso cProgram 1.3 single UNIX Specification 2. UNIX implementation 2.1 UNIX systemv Release 4, at&t's UNIX System laboratories 2.2 4.4bsd, Berkeley Software Distribution 2.3 FreeBSD, based on 4.4bsd-Lite 2.4 Linux 2.5 Mac OS X, a combination of Mach kernel and the FreeBSD operationg system 2.6 Solaris, Based on System V Release 4 3. Limits 3.1 compile-time limits, defined in the header file, can be determined by the header file. 3.2 runtime limits, requires the program to dynamically call the function to obtain the relevant limit value 3.2.1 sysconf independent of files and directories 3.2.2 pathconf/fpathconf related to files and directories