Linux man pages
SECTION 2

HOME Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Section 9
Name Section info
accept 2 accept, accept4 — accept a connection on a socket Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
access 2 access, faccessat — check user_zsingle_quotesz_s permissions for a file Synopsis #include <unistd.h> int a
acct 2 acct — switch process accounting on or off Synopsis #include <unistd.h> int acct( const char *filena
add_key 2 add_key — add a key to the kernel_zsingle_quotesz_s key management facility Synopsis #include <sys/types.h> #include <keyutils.h>
adjtimex 2 adjtimex, ntp_adjtime — tune kernel clock Synopsis #include <sys/timex.h> int adjtimex( struct timex
unimplemented 2 afs_syscall, break, fattach, fdetach, ftime, getmsg, getpmsg, gtty, isastream, lock, madvise1, mpx, prof, profil, putmsg, putpmsg, security, stty, tuxcall, ulimit, vserver — u
alarm 2 alarm — set an alarm clock for delivery of a signal Synopsis #include <unistd.h> unsigned int alarm(
alloc_hugepages 2 alloc_hugepages, free_hugepages — allocate or free huge pages Synopsis void *alloc_hugepages( int key,
arch_prctl 2 arch_prctl — set architecture-specific thread state Synopsis #include <asm/prctl.h> #include <sys/prctl.h>
posix_fadvise 2 posix_fadvise — predeclare an access pattern for file data Synopsis #include <fcntl.h> int posix_fadvise(
sync_file_range 2 sync_file_range — sync a file segment with disk Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h>
bdflush 2 bdflush — start, flush, or tune buffer-dirty-flush daemon Synopsis #include <sys/kdaemon.h> int bdflush(
bind 2 bind — bind a name to a socket Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
bpf 2 bpf — perform a command on an extended BPF map or program Synopsis #include <linux/bpf.h> int bpf(
brk 2 brk, sbrk — change data segment size Synopsis #include <unistd.h> int brk( void *addr);
cacheflush 2 cacheflush — flush contents of instruction and/or data cache Synopsis #include <asm/cachectl.h> int cachef
capget 2 capget, capset — set/get capabilities of thread(s) Synopsis #include <sys/capability.h> int capget(
chdir 2 chdir, fchdir — change working directory Synopsis #include <unistd.h> int chdir( const char *path);
chmod 2 chmod, fchmod, fchmodat — change permissions of a file Synopsis #include <sys/stat.h> int chmod(
chown 2 chown, fchown, lchown, fchownat — change ownership of a file Synopsis #include <unistd.h> int chown(
chroot 2 chroot — change root directory Synopsis #include <unistd.h> int chroot( const char *path);
clock_getres 2 clock_getres, clock_gettime, clock_settime — clock and time functions Synopsis #include <time.h> int clock
clock_nanosleep 2 clock_nanosleep — high-resolution sleep with specifiable clock Synopsis #include <time.h> int clock_nanosl
clone 2 clone, __clone2, clone3 — create a child process Synopsis /* Prototype for the glibc wrapper function */ #define _GNU_SOURCE #include <sched.h>
close 2 close — close a file descriptor Synopsis #include <unistd.h> int close( int fd);
connect 2 connect — initiate a connection on a socket Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
copy_file_range 2 copy_file_range — Copy a range of data from one file to another Synopsis #define _GNU_SOURCE #include <unistd.h>
open 2 open, openat, creat — open and possibly create a file Synopsis #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h>
create_module 2 create_module — create a loadable module entry Synopsis #include <linux/module.h> caddr_t create_module(
delete_module 2 delete_module — unload a kernel module Synopsis int delete_module( const char *name,
dup 2 dup, dup2, dup3 — duplicate a file descriptor Synopsis #include <unistd.h> int dup( int oldfd);
epoll_create 2 epoll_create, epoll_create1 — open an epoll file descriptor Synopsis #include <sys/epoll.h> int epoll_crea
epoll_ctl 2 epoll_ctl — control interface for an epoll file descriptor Synopsis #include <sys/epoll.h> int epoll_ctl(
epoll_wait 2 epoll_wait, epoll_pwait — wait for an I/O event on an epoll file descriptor Synopsis #include <sys/epoll.h> int
eventfd 2 eventfd — create a file descriptor for event notification Synopsis #include <sys/eventfd.h> int eventfd(
execveat 2 execveat — execute program relative to a directory file descriptor Synopsis #include <unistd.h> int execve
execve 2 execve — execute program Synopsis #include <unistd.h> int execve( const char *pathname,
_exit 2 _exit, _Exit — terminate the calling process Synopsis #include <unistd.h> void _exit( int status);
exit_group 2 exit_group — exit all threads in a process Synopsis #include <linux/unistd.h> void exit_group( int s
fallocate 2 fallocate — manipulate file space Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h>
fanotify_init 2 fanotify_init — create and initialize fanotify group Synopsis #include <fcntl.h> #include <sys/fanotify.h>
fanotify_mark 2 fanotify_mark — add, remove, or modify an fanotify mark on a filesystem object Synopsis #include <sys/fanotify.h> int
fcntl 2 fcntl — manipulate file descriptor Synopsis #include <unistd.h> #include <fcntl.h> int fcnt
fsync 2 fsync, fdatasync — synchronize a file_zsingle_quotesz_s in-core state with storage device Synopsis #include <unistd.h>
select 2 select, pselect, FD_CLR, FD_ISSET, FD_SET, FD_ZERO — synchronous I/O multiplexing Synopsis /* According to POSIX.1-2001, POSIX.1-2008 */ #include <sys/s
getxattr 2 getxattr, lgetxattr, fgetxattr — retrieve an extended attribute value Synopsis #include <sys/types.h> #include <sys/xattr.h>
init_module 2 init_module, finit_module — load a kernel module Synopsis int init_module( void *module_image,
listxattr 2 listxattr, llistxattr, flistxattr — list extended attribute names Synopsis #include <sys/types.h> #include <sys/xattr.h>
flock 2 flock — apply or remove an advisory lock on an open file Synopsis #include <sys/file.h> int flock(
fork 2 fork — create a child process Synopsis #include <sys/types.h> #include <unistd.h> pid_t fo
removexattr 2 removexattr, lremovexattr, fremovexattr — remove an extended attribute Synopsis #include <sys/types.h> #include <sys/xattr.h>
setxattr 2 setxattr, lsetxattr, fsetxattr — set an extended attribute value Synopsis #include <sys/types.h> #include <sys/xattr.h>
stat 2 stat, fstat, lstat, fstatat — get file status Synopsis #include <sys/types.h> #include <sys/stat.h> #include <unistd.h>
statfs 2 statfs, fstatfs — get filesystem statistics Synopsis #include <sys/vfs.h> /* or <sys/statfs.h> */ int
truncate 2 truncate, ftruncate — truncate a file to a specified length Synopsis #include <unistd.h> #include <sys/types.h>
futex 2 futex — fast user-space locking Synopsis #include <linux/futex.h> #include <sys/time.h> int
utimensat 2 utimensat, futimens — change file timestamps with nanosecond precision Synopsis #include <fcntl.h> /* Definition of AT_* constants */ #include <sy
futimesat 2 futimesat — change timestamps of a file relative to a directory file descriptor Synopsis #include <fcntl.h> /* Definition of AT_* constants */ #inclu
getcpu 2 getcpu — determine CPU and NUMA node on which the calling thread is running Synopsis #include <linux/getcpu.h> int
getdents 2 getdents, getdents64 — get directory entries Synopsis int getdents( unsigned int fd,
getdomainname 2 getdomainname, setdomainname — get/set NIS domain name Synopsis #include <unistd.h> int getdomainname(
getgid 2 getgid, getegid — get group identity Synopsis #include <unistd.h> #include <sys/types.h> gid_t
getuid 2 getuid, geteuid — get user identity Synopsis #include <unistd.h> #include <sys/types.h> uid_t
getgroups 2 getgroups, setgroups — get/set list of supplementary group IDs Synopsis #include <sys/types.h> #include <unistd.h>
gethostname 2 gethostname, sethostname — get/set hostname Synopsis #include <unistd.h> int gethostname( char *name
getpagesize 2 getpagesize — get memory page size Synopsis #include <unistd.h> int getpagesize( void);
getitimer 2 getitimer, setitimer — get or set value of an interval timer Synopsis #include <sys/time.h> int getitimer(
getpeername 2 getpeername — get name of connected peer socket Synopsis #include <sys/socket.h> int getpeername( in
setpgid 2 setpgid, getpgid, setpgrp, getpgrp — set/get process group Synopsis #include <sys/types.h> #include <unistd.h>
getpid 2 getpid, getppid — get process identification Synopsis #include <sys/types.h> #include <unistd.h> pid_t
getpriority 2 getpriority, setpriority — get/set program scheduling priority Synopsis #include <sys/time.h> #include <sys/resource.h>
getrandom 2 getrandom — obtain a series of random bytes Synopsis #include <sys/random.h> ssize_t getrandom( void
getresuid 2 getresuid, getresgid — get real, effective and saved user/group IDs Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <un
getrlimit 2 getrlimit, setrlimit, prlimit — get/set resource limits Synopsis #include <sys/time.h> #include <sys/resource.h>
getrusage 2 getrusage — get resource usage Synopsis #include <sys/time.h> #include <sys/resource.h> int
getsid 2 getsid — get session ID Synopsis #include <sys/types.h> #include <unistd.h> pid_t getsid(
getsockname 2 getsockname — get socket name Synopsis #include <sys/socket.h> int getsockname( int sockfd,
getsockopt 2 getsockopt, setsockopt — get and set options on sockets Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
gettid 2 gettid — get thread identification Synopsis #include <sys/types.h> pid_t gettid( void);
get_mempolicy 2 get_mempolicy — retrieve NUMA memory policy for a thread Synopsis #include <numaif.h> long get_mempolicy(
get_kernel_syms 2 get_kernel_syms — retrieve exported kernel and module symbols Synopsis #include <linux/module.h> int get_k
get_robust_list 2 get_robust_list, set_robust_list — get/set list of robust futexes Synopsis #include <linux/futex.h> #include <sys/types.h> #include <syscall
set_thread_area 2 get_thread_area, set_thread_area — manipulate thread-local storage information Synopsis #include <linux/unistd.h> #if defined __i386__ || defined __
idle 2 idle — make process 0 idle Synopsis #include <unistd.h> int idle( void);  
outb 2 outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p — port I/O Synopsis #include <s
inotify_add_watch 2 inotify_add_watch — add a watch to an initialized inotify instance Synopsis #include <sys/inotify.h> int i
inotify_init 2 inotify_init, inotify_init1 — initialize an inotify instance Synopsis #include <sys/inotify.h> int inotify
inotify_rm_watch 2 inotify_rm_watch — remove an existing watch from an inotify instance Synopsis #include <sys/inotify.h> int
intro 2 intro — introduction to system calls DESCRIPTION Section 2 of the manual describes the Linux system calls. A system call is an entry point into the Linux ker
ioctl 2 ioctl — control device Synopsis #include <sys/ioctl.h> int ioctl( int fd,
ioctl_console 2 ioctl_console — ioctls for console terminal and virtual consoles DESCRIPTION The following Linux-specific ioctl(2) requests are supported for console t
ioctl_fat 2 Name ioctl_fat — manipulating the FAT filesystem Synopsis #include <linux/msdos_fs.h> #include <sys/io
ioctl_ficlonerange 2   Name ioctl_ficlonerange, ioctl_ficlone — share some the data of one file with another file Synopsis
ioctl_fideduperange 2   Name ioctl_fideduperange — share some the data of one file with another file Synopsis #include
ioctl_getfsmap 2 ioctl_getfsmap — retrieve the physical layout of the filesystem Synopsis #include <sys/ioctl.h> #include <linux/fs.h> #include <linux/fsmap.
ioctl_iflags 2 ioctl_iflags — ioctl() operations for inode flags DESCRIPTION Various Linux filesystems support the notion of inode flags—attributes that modif
ioctl_list 2 ioctl_list — list of ioctl calls in Linux/i386 kernel DESCRIPTION This is Ioctl List 1.3.27, a list of ioctl calls in Linux/i386 kernel 1.3.27. It cont
gettimeofday 2 gettimeofday, settimeofday — get / set time Synopsis #include <sys/time.h> int gettimeofday( struct
getunwind 2 getunwind — copy the unwind data to caller_zsingle_quotesz_s buffer Synopsis #include <syscall.h> #include <linux/unwind.h>
ioctl_ns 2 ioctl_ns — ioctl() operations for Linux namespaces DESCRIPTION Discovering namespace relationships The following ioctl(2) operatio
ioctl_tty 2 ioctl_tty — ioctls for terminals and serial lines Synopsis #include <termios.h> int ioctl( int
ioctl_userfaultfd 2 ioctl_userfaultfd — create a file descriptor for handling page faults in user space Synopsis #include <sys/ioctl.h> in
ioperm 2 ioperm — set port input/output permissions Synopsis #include <sys/io.h> /* for glibc */ int ioper
iopl 2 iopl — change I/O privilege level Synopsis #include <sys/io.h> int iopl( int level);
ioprio_set 2 ioprio_get, ioprio_set — get/set I/O scheduling class and priority Synopsis int ioprio_get( int which,
io_cancel 2 io_cancel — cancel an outstanding asynchronous I/O operation Synopsis #include <linux/aio_abi.h> /* Defines needed types */
io_destroy 2 io_destroy — destroy an asynchronous I/O context Synopsis #include <linux/aio_abi.h> /* Defines needed types */ in
io_getevents 2 io_getevents — read asynchronous I/O events from the completion queue Synopsis #include <linux/aio_abi.h> /* Defines needed types */ #includ
io_setup 2 io_setup — create an asynchronous I/O context Synopsis #include <linux/aio_abi.h> /* Defines needed types */ int
io_submit 2 io_submit — submit asynchronous I/O blocks for processing Synopsis #include <linux/aio_abi.h> /* Defines needed types */
ipc 2 ipc — System V IPC system calls Synopsis int ipc( unsigned int call,  
kcmp 2 kcmp — compare two processes to determine if they share a kernel resource Synopsis #include <linux/kcmp.h> int
kexec_load 2 kexec_load, kexec_file_load — load a new kernel for later execution Synopsis #include <linux/kexec.h> long
keyctl 2 keyctl — manipulate the kernel_zsingle_quotesz_s key management facility Synopsis #include <sys/types.h> #include <keyutils.h>
kill 2 kill — send signal to a process Synopsis #include <sys/types.h> #include <signal.h> int kil
syslog 2 syslog, klogctl — read and/or clear kernel message ring buffer; set console_loglevel Synopsis int syslog( in
link 2 link, linkat — make a new name for a file Synopsis #include <unistd.h> int link( const char *oldpath
listen 2 listen — listen for connections on a socket Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
llseek 2 _llseek — reposition read/write file offset Synopsis #include <sys/types.h> #include <unistd.h> int
lookup_dcookie 2 lookup_dcookie — return a directory entry_zsingle_quotesz_s path Synopsis int lookup_dcookie( u64 cookie,
lseek 2 lseek — reposition read/write file offset Synopsis #include <sys/types.h> #include <unistd.h> off_t
madvise 2 madvise — give advice about use of memory Synopsis #include <sys/mman.h> int madvise( void *addr,
membarrier 2 membarrier — issue memory barriers on a set of threads Synopsis #include <linux/membarrier.h> int membarri
memfd_create 2 memfd_create — create an anonymous file Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/mman.h>
migrate_pages 2 migrate_pages — move all pages in a process to another set of nodes Synopsis #include <numaif.h> long migr
mincore 2 mincore — determine whether pages are resident in memory Synopsis #include <unistd.h> #include <sys/mman.h>
mkdir 2 mkdir, mkdirat — create a directory Synopsis #include <sys/stat.h> #include <sys/types.h> int
mknod 2 mknod, mknodat — create a special or ordinary file Synopsis #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <
mlock 2 mlock, mlock2, munlock, mlockall, munlockall — lock and unlock memory Synopsis #include <sys/mman.h> int m
mmap 2 mmap, munmap — map or unmap files or devices into memory Synopsis #include <sys/mman.h> void *mmap(
mmap2 2 mmap2 — map files or devices into memory Synopsis #include <sys/mman.h> void *mmap2( void *addr,
modify_ldt 2 modify_ldt — get or set a per-process LDT entry Synopsis #include <sys/types.h> int modify_ldt( int
mount 2 mount — mount filesystem Synopsis #include <sys/mount.h> int mount( const char *source,
move_pages 2 move_pages — move individual pages of a process to another node Synopsis #include <numaif.h> long move_pag
mprotect 2 mprotect, pkey_mprotect — set protection on a region of memory Synopsis #include <sys/mman.h> int mprotect
mq_getsetattr 2 mq_getsetattr — get/set message queue attributes Synopsis #include <sys/types.h> #include <mqueue.h> in
mremap 2 mremap — remap a virtual memory address Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/mman.h>
msgctl 2 msgctl — System V message control operations Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h>
msgget 2 msgget — get a System V message queue identifier Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h>
msgop 2 msgrcv, msgsnd — System V message queue operations Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/msg.h>
msync 2 msync — synchronize a file with a memory map Synopsis #include <sys/mman.h> int msync( void *addr,
open_by_handle_at 2 name_to_handle_at, open_by_handle_at — obtain handle for a pathname and open file via a handle Synopsis #define _GNU_SOURCE /* See feature_test_ma
nanosleep 2 nanosleep — high-resolution sleep Synopsis #include <time.h> int nanosleep( const struct timespec *r
nice 2 nice — change process priority Synopsis #include <unistd.h> int nice( int inc);
nfsservctl 2 nfsservctl — syscall interface to kernel nfs daemon Synopsis #include <linux/nfsd/syscall.h> long nfsservc
uname 2 uname — get name and information about current kernel Synopsis #include <sys/utsname.h> int uname(
pause 2 pause — wait for signal Synopsis #include <unistd.h> int pause( void);  
pciconfig_read 2 pciconfig_read, pciconfig_write, pciconfig_iobase — pci device information handling Synopsis #include <pci.h> int
perfmonctl 2 perfmonctl — interface to IA-64 performance monitoring unit Synopsis #include <syscall.h> #include <perfmon.h>
perf_event_open 2 perf_event_open — set up performance monitoring Synopsis #include <linux/perf_event.h> #include <linux/hw_breakpoint.h>
personality 2 personality — set the process execution domain Synopsis #include <sys/personality.h> int personality(
pidfd_open 2 pidfd_open — obtain a file descriptor that refers to a process Synopsis #include <sys/types.h> int pidfd_o
pidfd_send_signal 2 pidfd_send_signal — send a signal to a process specified by a file descriptor Synopsis #include <signal.h> int
pipe 2 pipe, pipe2 — create pipe Synopsis #include <unistd.h> /* On Alpha, IA-64, MIPS, SuperH, and SPARC/SPARC64; see NOTES */ struct fd_pair { long fd[2];
pivot_root 2 pivot_root — change the root mount Synopsis int pivot_root( const char *new_root,
pkey_alloc 2 pkey_alloc, pkey_free — allocate or free a protection key Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/mman.
poll 2 poll, ppoll — wait for some event on a file descriptor Synopsis #include <poll.h> int poll( st
prctl 2 prctl — operations on a process Synopsis #include <sys/prctl.h> int prctl( int option,
pread 2 pread, pwrite — read from or write to a file descriptor at a given offset Synopsis #include <unistd.h> ssize_t
readv 2 readv, writev, preadv, pwritev, preadv2, pwritev2 — read or write data into multiple buffers Synopsis #include <sys/uio.h>
process_vm_readv 2 process_vm_readv, process_vm_writev — transfer data between process address spaces Synopsis #include <sys/uio.h> ssize
ptrace 2 ptrace — process trace Synopsis #include <sys/ptrace.h> long ptrace( enum __ptrace_request request,
query_module 2 query_module — query the kernel for various bits pertaining to modules Synopsis #include <linux/module.h> int
quotactl 2 quotactl — manipulate disk quotas Synopsis #include <sys/quota.h> #include <xfs/xqm.h> /* for XFS quotas */
read 2 read — read from a file descriptor Synopsis #include <unistd.h> ssize_t read( int fd,
readahead 2 readahead — initiate file readahead into page cache Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h>
readdir 2 readdir — read directory entry Synopsis int readdir( unsigned int fd,  
readlink 2 readlink, readlinkat — read value of a symbolic link Synopsis #include <unistd.h> ssize_t readlink(
reboot 2 reboot — reboot or enable/disable Ctrl-Alt-Del Synopsis /* Since kernel version 2.1.30 there are symbolic names LINUX_REBOOT_* for the constants and a fourth
recv 2 recv, recvfrom, recvmsg — receive a message from a socket Synopsis #include <sys/types.h> #include <sys/socket.h>
recvmmsg 2 recvmmsg — receive multiple messages on a socket Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/socket.h>
remap_file_pages 2 remap_file_pages — create a nonlinear file mapping Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/mman.h>
rename 2 rename, renameat, renameat2 — change the name or location of a file Synopsis #include <stdio.h> int rename
restart_syscall 2 restart_syscall — restart a system call after interruption by a stop signal Synopsis int restart_syscall(void);
request_key 2 request_key — request a key from the kernel_zsingle_quotesz_s key management facility Synopsis #include <sys/types.h> #include <keyutils.h>
sigaction 2 sigaction, rt_sigaction — examine and change a signal action Synopsis #include <signal.h> int sigaction(
sigpending 2 sigpending, rt_sigpending — examine pending signals Synopsis #include <signal.h> int sigpending(
sigprocmask 2 sigprocmask, rt_sigprocmask — examine and change blocked signals Synopsis #include <signal.h> /* Prototype for the glibc wrapper function */
rt_sigqueueinfo 2 rt_sigqueueinfo, rt_tgsigqueueinfo — queue a signal and data Synopsis int rt_sigqueueinfo( pid_t tgid,
sigreturn 2 sigreturn, rt_sigreturn — return from signal handler and cleanup stack frame Synopsis int sigreturn( ...);
sigsuspend 2 sigsuspend, rt_sigsuspend — wait for a signal Synopsis #include <signal.h> int sigsuspend( const sig
sigwaitinfo 2 sigwaitinfo, sigtimedwait, rt_sigtimedwait — synchronously wait for queued signals Synopsis #include <signal.h> int
s390_guarded_storage 2 s390_guarded_storage — operations with z/Architecture guarded storage facility Synopsis #include <asm/guarded_storage.h>
s390_pci_mmio_write 2 s390_pci_mmio_write, s390_pci_mmio_read — transfer data to/from PCI MMIO memory page Synopsis #include <asm/unistd.h>
s390_runtime_instr 2 s390_runtime_instr — enable/disable s390 CPU run-time instrumentation Synopsis #include <asm/runtime_instr.h> int
s390_sthyi 2 s390_sthyi — emulate STHYI instruction Synopsis #include <asm/unistd.h> int s390_sthyi( unsigned lon
sched_setaffinity 2 sched_setaffinity, sched_getaffinity — set and get a thread_zsingle_quotesz_s CPU affinity mask Synopsis #define _GNU_SOURCE /* See feature_te
sched_setattr 2 sched_setattr, sched_getattr — set and get scheduling policy and attributes Synopsis #include <sched.h> int
sched_setparam 2 sched_setparam, sched_getparam — set and get scheduling parameters Synopsis #include <sched.h> int sched_s
sched_setscheduler 2 sched_setscheduler, sched_getscheduler — set and get scheduling policy/parameters Synopsis #include <sched.h> int
sched_get_priority_max 2   Name sched_get_priority_max, sched_get_priority_min — get static priority range Synopsis #i
sched_rr_get_interval 2   Name sched_rr_get_interval — get the SCHED_RR interval for the named process Synopsis #inclu
sched_yield 2 sched_yield — yield the processor Synopsis #include <sched.h> int sched_yield( void);  
seccomp 2 seccomp — operate on Secure Computing state of the process Synopsis #include <linux/seccomp.h> #include <linux/filter.h> #include <linux/aud
select_tut 2 select, pselect, FD_CLR, FD_ISSET, FD_SET, FD_ZERO — synchronous I/O multiplexing Synopsis /* According to POSIX.1-2001, POSIX.1-2008 */ #include <sys/s
semctl 2 semctl — System V semaphore control operations Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h>
semget 2 semget — get a System V semaphore set identifier Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h>
send 2 send, sendto, sendmsg — send a message on a socket Synopsis #include <sys/types.h> #include <sys/socket.h>
semop 2 semop, semtimedop — System V semaphore operations Synopsis #include <sys/types.h> #include <sys/ipc.h> #include <sys/sem.h>
sendfile 2 sendfile — transfer data between file descriptors Synopsis #include <sys/sendfile.h> ssize_t sendfile(
sendmmsg 2 sendmmsg — send multiple messages on a socket Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sys/socket.h>
seteuid 2 seteuid, setegid — set effective user or group ID Synopsis #include <sys/types.h> #include <unistd.h>
setfsgid 2 setfsgid — set group identity used for filesystem checks Synopsis #include <sys/fsuid.h> int setfsgid(
setfsuid 2 setfsuid — set user identity used for filesystem checks Synopsis #include <sys/fsuid.h> int setfsuid(
setgid 2 setgid — set group identity Synopsis #include <sys/types.h> #include <unistd.h> int setgid
setns 2 setns — reassociate thread with a namespace Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <sched.h>
setreuid 2 setreuid, setregid — set real and/or effective user or group ID Synopsis #include <sys/types.h> #include <unistd.h>
setresuid 2 setresuid, setresgid — set real, effective and saved user or group ID Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <
setsid 2 setsid — creates a session and sets the process group ID Synopsis #include <sys/types.h> #include <unistd.h>
setuid 2 setuid — set user identity Synopsis #include <sys/types.h> #include <unistd.h> int setuid(
setup 2 setup — setup devices and filesystems, mount root filesystem Synopsis #include <unistd.h> int setup(
set_mempolicy 2 set_mempolicy — set default NUMA memory policy for a thread and its children Synopsis #include <numaif.h> long
set_tid_address 2 set_tid_address — set pointer to thread ID Synopsis #include <linux/unistd.h> long set_tid_address(
sgetmask 2 sgetmask, ssetmask — manipulation of signal mask (obsolete) Synopsis long sgetmask( void);  
shmop 2 shmat, shmdt — System V shared memory operations Synopsis #include <sys/types.h> #include <sys/shm.h> v
shmctl 2 shmctl — System V shared memory control Synopsis #include <sys/ipc.h> #include <sys/shm.h> int
shmget 2 shmget — allocates a System V shared memory segment Synopsis #include <sys/ipc.h> #include <sys/shm.h>
shutdown 2 shutdown — shut down part of a full-duplex connection Synopsis #include <sys/socket.h> int shutdown(
sigaltstack 2 sigaltstack — set and/or get signal stack context Synopsis #include <signal.h> int sigaltstack(
signal 2 signal — ANSI C signal handling Synopsis #include <signal.h> typedef void (*sighandler_t)(int); sighandler_t
signalfd 2 signalfd — create a file descriptor for accepting signals Synopsis #include <sys/signalfd.h> int signalfd(
socket 2 socket — create an endpoint for communication Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
socketcall 2 socketcall — socket system calls Synopsis #include <linux/net.h> int socketcall( int call,
socketpair 2 socketpair — create a pair of connected sockets Synopsis #include <sys/types.h> /* See NOTES */ #include <sys/socket.h>
splice 2 splice — splice data to/from a pipe Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h>
spu_create 2 spu_create — create a new spu context Synopsis #include <sys/types.h> #include <sys/spu.h> int
spu_run 2 spu_run — execute an SPU context Synopsis #include <sys/spu.h> int spu_run( int fd,
statx 2 statx — get file status (extended) Synopsis #include <sys/types.h> #include <sys/stat.h> #include <unistd.h> #include <fcntl.h>
stime 2 stime — set time Synopsis #include <time.h> int stime( const time_t *t);
subpage_prot 2 subpage_prot — define a subpage protection for an address range Synopsis long subpage_prot( unsigned long ad
swapon 2 swapon, swapoff — start/stop swapping to file/device Synopsis #include <unistd.h> #include <sys/swap.h>
symlink 2 symlink, symlinkat — make a new name for a file Synopsis #include <unistd.h> int symlink( const char
sync 2 sync, syncfs — commit filesystem caches to disk Synopsis #include <unistd.h> void sync( void);
syscall 2 syscall — indirect system call Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <unistd.h> #include <sys/syscall.h>
syscalls 2 syscalls — Linux system calls Synopsis Linux system calls. DESCRIPTION The system call is the fundamental interface betwe
sysctl 2 sysctl — read/write system parameters Synopsis #include <unistd.h> #include <linux/sysctl.h> int
sysfs 2 sysfs — get filesystem type information Synopsis int sysfs( int option,  
sysinfo 2 sysinfo — return system information Synopsis #include <sys/sysinfo.h> int sysinfo( struct sysinfo *i
tee 2 tee — duplicating pipe content Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h>
tkill 2 tkill, tgkill — send a signal to a thread Synopsis int tkill( int tid,  
time 2 time — get time in seconds Synopsis #include <time.h> time_t time( time_t *tloc);
timerfd_create 2 timerfd_create, timerfd_settime, timerfd_gettime — timers that notify via file descriptors Synopsis #include <sys/timerfd.h>
timer_create 2 timer_create — create a POSIX per-process timer Synopsis #include <signal.h> #include <time.h> int
timer_delete 2 timer_delete — delete a POSIX per-process timer Synopsis #include <time.h> int timer_delete( timer_t
timer_getoverrun 2 timer_getoverrun — get overrun count for a POSIX per-process timer Synopsis #include <time.h> int timer_ge
timer_settime 2 timer_settime, timer_gettime — arm/disarm and fetch state of POSIX per-process timer Synopsis #include <time.h> int
times 2 times — get process times Synopsis #include <sys/times.h> clock_t times( struct tms *buf);
umask 2 umask — set file mode creation mask Synopsis #include <sys/types.h> #include <sys/stat.h> mode_t
umount 2 umount, umount2 — unmount filesystem Synopsis #include <sys/mount.h> int umount( const char *target)
unlink 2 unlink, unlinkat — delete a name and possibly the file it refers to Synopsis #include <unistd.h> int unlin
unshare 2 unshare — disassociate parts of the process execution context Synopsis #define _GNU_SOURCE #include <sched.h>
uselib 2 uselib — load shared library Synopsis #include <unistd.h> int uselib( const char *library);
userfaultfd 2 userfaultfd — create a file descriptor for handling page faults in user space Synopsis #include <sys/types.h> #include <linux/userfaultfd.h>
ustat 2 ustat — get filesystem statistics Synopsis #include <sys/types.h> #include <unistd.h> /* libc[45] */ #include <ustat.h> /* glibc2 */
utime 2 utime, utimes — change file last access and modification times Synopsis #include <sys/types.h> #include <utime.h>
vfork 2 vfork — create a child process and block parent Synopsis #include <sys/types.h> #include <unistd.h> pi
vhangup 2 vhangup — virtually hangup the current terminal Synopsis #include <unistd.h> int vhangup( void);
vm86 2 vm86old, vm86 — enter virtual 8086 mode Synopsis #include <sys/vm86.h> int vm86old( struct vm86_stru
vmsplice 2 vmsplice — splice user pages to/from a pipe Synopsis #define _GNU_SOURCE /* See feature_test_macros(7) */ #include <fcntl.h> #include <sys/uio.
wait 2 wait, waitpid, waitid — wait for process to change state Synopsis #include <sys/types.h> #include <sys/wait.h>
wait4 2 wait3, wait4 — wait for process to change state, BSD style Synopsis #include <sys/types.h> #include <sys/time.h> #include <sys/resource.h>
write 2 write — write to a file descriptor Synopsis #include <unistd.h> ssize_t write( int fd,
_syscall 2 _syscall — invoking a system call without library support (OBSOLETE) Synopsis #include <linux/unistd.h> A _syscall macro desired system call