Added functions from POSIX standard.

doc/posix1003.1/ch04.t

@@ -7,27 +7,117 @@
 @c
 
 @chapter Process Environment
+
 @section Process Identification
+
 @subsection Get Process and Parent Process IDs
+
+@example
+getpid()
+getppid()
+@end example
+
 @section User Identification
+
 @subsection Get Real User Effective User Real Group and Effective Group IDs
+
+@example
+getuid()
+geteuid()
+getgid()
+getegid()
+@end example
+
 @subsection Set User and Group IDs
+
+@example
+setuid()
+setgid()
+@end example
+
 @subsection Get Supplementary Group IDs
+
+@example
+getgroups()
+@end example
+
 @subsection Get User Name
+
+@example
+getlogin()
+getlogin_r()
+@end example
+
 @section Process Groups
+
 @subsection Get Process Group ID
+
+@example
+getpgrp()
+@end example
+
 @subsection Create Session and Set Process Group ID
+
+@example
+setsid()
+@end example
+
 @subsection Set Process Group ID for Job Control
+
+@example
+setpgid()
+@end example
+
 @section System Identification
+
 @subsection Get System Name
+
+@example
+uname()
+@end example
+
 @section Time
+
 @subsection Get System Time
+
+@example
+time()
+@end example
+
 @subsection Get Process Times
+
+@example
+times()
+@end example
+
 @section Environment Variables
+
 @subsection Environment Access
+
+@example
+getenv()
+@end example
+
 @section Terminal Identification
+
 @subsection Generate Terminal Pathname
+
+@example
+ctermid()
+@end example
+
 @subsection Determine Terminal Device Name
+
+@example
+ttyname()
+ttyname_r()
+isatty()
+@end example
+
 @section Configurable System Variables
+
 @subsection Get Configurable System Variables
 
+@example
+sysconf()
+@end example