Process Environment [POSIX Section 4]

int uname( struct utsname *name ); 
time_t time( time_t *tloc ); 
char *getenv( const char *name ); 
int isatty( int fd );
long sysconf( int name );

pid_t getpid( void ); 
pid_t getppid( void ); 
uid_t getuid( void ); 
uid_t geteuid( void ); 
gid_t getgid( void ); 
gid_t getegid( void ); 
int setuid( uid_t uid ); 
int setgid( gid_t gid ); 
int getgroups( int gidsetsize, gid_t grouplist[] ); 
char *getlogin( void ); 
int getlogin_r( char *name, size_t namesize ); 
pid_t getpgrp( void ); 
pid_t setsid( void );
int setpgid( pid_t pid, pid_t pgid ); 
char *ctermid( char *s); 
char *ttyname( int fd );                             // TBA 
int ttyname_r( int fd, char *name, size_t namesize); // TBA 
clock_t times( struct tms *buffer );                 // TBA