4.  Kernel primitives

1.1. Process naming and protection

sethostid           set UNIX host id
gethostid           get UNIX host id
sethostname         set UNIX host name
gethostname         get UNIX host name
getpid              get process id
fork                create new process
exit                terminate a process
execve              execute a different process
getuid              get user id
geteuid             get effective user id
setreuid            set real and effective user id's
getgid              get accounting group id
getegid             get effective accounting group id
getgroups           get access group set
setregid            set real and effective group id's
setgroups           set access group set
getpgrp             get process group
setpgrp             set process group

1.2 Memory management
<sys/mman.h>        memory management definitions
sbrk                change data section size
sstk                change stack section size
getpagesize         get memory page size
mmap                map pages of memory
msync               flush modified mapped pages to filesystem
munmap              unmap memory
mprotect            change protection of pages
madvise             give memory management advice
mincore             determine core residency of pages
msleep              sleep on a lock
mwakeup             wakeup process sleeping on a lock

1.3 Signals
<signal.h>          signal definitions
sigvec              set handler for signal
kill                send signal to process
killpgrp            send signal to process group
sigblock            block set of signals
sigsetmask          restore set of blocked signals
sigpause            wait for signals
sigstack            set software stack for signals

1.4 Timing and statistics
<sys/time.h>        time-related definitions
gettimeofday        get current time and timezone
settimeofday        set current time and timezone
getitimer           read an interval timer
setitimer           get and set an interval timer
profil              profile process

1.5 Descriptors
getdtablesize       descriptor reference table size
dup                 duplicate descriptor
dup2                duplicate to specified index
close               close descriptor
select              multiplex input/output
fcntl               control descriptor options
wrap                wrap descriptor with protocol

1.6 Resource controls
<sys/resource.h>    resource-related definitions
getpriority         get process priority
setpriority         set process priority
getrusage           get resource usage
getrlimit           get resource limitations
setrlimit           set resource limitations

1.7 System operation support
mount                mount a device file system
swapon               add a swap device
umount               umount a file system
sync                 flush system caches
reboot               reboot a machine
acct                 specify accounting file