Added in API level 21

Summary: Methods | Inherited Methods

Os

Kotlin |Java

public final class Os
extends Object

java.lang.Object
↳	android.system.Os

Access to low-level system functionality. Most of these are system calls. Most users will want to use higher-level APIs where available, but this class provides access to the underlying primitives used to implement the higher-level APIs.

The corresponding constants can be found in OsConstants.

Summary

Public methods
`static FileDescriptor`	`accept(FileDescriptor fd, InetSocketAddress peerAddress)` See accept(2).
`static boolean`	`access(String path, int mode)` See access(2).
`static void`	`bind(FileDescriptor fd, InetAddress address, int port)` See bind(2).
`static void`	`bind(FileDescriptor fd, SocketAddress address)` See bind(2).
`static void`	`chmod(String path, int mode)` See chmod(2).
`static void`	`chown(String path, int uid, int gid)` See chown(2).
`static void`	`close(FileDescriptor fd)` See close(2).
`static void`	`connect(FileDescriptor fd, InetAddress address, int port)` See connect(2).
`static void`	`connect(FileDescriptor fd, SocketAddress address)` See connect(2).
`static FileDescriptor`	`dup(FileDescriptor oldFd)` See dup(2).
`static FileDescriptor`	`dup2(FileDescriptor oldFd, int newFd)` See dup2(2).
`static String[]`	`environ()` See environ(3).
`static void`	`execv(String filename, String[] argv)` See exec(3).
`static void`	`execve(String filename, String[] argv, String[] envp)` See execve(2).
`static void`	`fchmod(FileDescriptor fd, int mode)` See fchmod(2).
`static void`	`fchown(FileDescriptor fd, int uid, int gid)` See fchown(2).
`static int`	`fcntlInt(FileDescriptor fd, int cmd, int arg)` See fcntl(2).
`static void`	`fdatasync(FileDescriptor fd)` See fdatasync(2).
`static StructStat`	`fstat(FileDescriptor fd)` See fstat(2).
`static StructStatVfs`	`fstatvfs(FileDescriptor fd)` See fstatvfs(2).
`static void`	`fsync(FileDescriptor fd)` See fsync(2).
`static void`	`ftruncate(FileDescriptor fd, long length)` See ftruncate(2).
`static String`	`gai_strerror(int error)` See gai_strerror(3).
`static int`	`getegid()` See getegid(2).
`static String`	`getenv(String name)` See getenv(3).
`static int`	`geteuid()` See geteuid(2).
`static int`	`getgid()` See getgid(2).
`static SocketAddress`	`getpeername(FileDescriptor fd)` See getpeername(2).
`static int`	`getpid()` See getpid(2).
`static int`	`getppid()` See getppid(2).
`static SocketAddress`	`getsockname(FileDescriptor fd)` See getsockname(2).
`static StructTimeval`	`getsockoptTimeval(FileDescriptor fd, int level, int option)` See getsockopt(2).
`static int`	`gettid()` See gettid(2).
`static int`	`getuid()` See getuid(2).
`static byte[]`	`getxattr(String path, String name)` See getxattr(2)
`static String`	`if_indextoname(int index)` See if_indextoname(3).
`static int`	`if_nametoindex(String name)` See if_nametoindex(3).
`static InetAddress`	`inet_pton(int family, String address)` See inet_pton(3).
`static boolean`	`isatty(FileDescriptor fd)` See isatty(3).
`static void`	`kill(int pid, int signal)` See kill(2).
`static void`	`lchown(String path, int uid, int gid)` See lchown(2).
`static void`	`link(String oldPath, String newPath)` See link(2).
`static void`	`listen(FileDescriptor fd, int backlog)` See listen(2).
`static String[]`	`listxattr(String path)` See listxattr(2)
`static long`	`lseek(FileDescriptor fd, long offset, int whence)` See lseek(2).
`static StructStat`	`lstat(String path)` See lstat(2).
`static FileDescriptor`	`memfd_create(String name, int flags)` See memfd_create(2).
`static void`	`mincore(long address, long byteCount, byte[] vector)` See mincore(2).
`static void`	`mkdir(String path, int mode)` See mkdir(2).
`static void`	`mkfifo(String path, int mode)` See mkfifo(3).
`static void`	`mlock(long address, long byteCount)` See mlock(2).
`static long`	`mmap(long address, long byteCount, int prot, int flags, FileDescriptor fd, long offset)` See mmap(2).
`static void`	`msync(long address, long byteCount, int flags)` See msync(2).
`static void`	`munlock(long address, long byteCount)` See munlock(2).
`static void`	`munmap(long address, long byteCount)` See munmap(2).
`static FileDescriptor`	`open(String path, int flags, int mode)` See open(2).
`static FileDescriptor[]`	`pipe()` See pipe(2).
`static int`	`poll(StructPollfd[] fds, int timeoutMs)` See poll(2).
`static void`	`posix_fallocate(FileDescriptor fd, long offset, long length)` See posix_fallocate(3).
`static int`	`prctl(int option, long arg2, long arg3, long arg4, long arg5)` See prctl(2).
`static int`	`pread(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount, long offset)` See pread(2).
`static int`	`pread(FileDescriptor fd, ByteBuffer buffer, long offset)` See pread(2).
`static int`	`pwrite(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount, long offset)` See pwrite(2).
`static int`	`pwrite(FileDescriptor fd, ByteBuffer buffer, long offset)` See pwrite(2).
`static int`	`read(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount)` See read(2).
`static int`	`read(FileDescriptor fd, ByteBuffer buffer)` See read(2).
`static String`	`readlink(String path)` See readlink(2).
`static int`	`readv(FileDescriptor fd, Object[] buffers, int[] offsets, int[] byteCounts)` See readv(2).
`static int`	`recvfrom(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount, int flags, InetSocketAddress srcAddress)` See recvfrom(2).
`static int`	`recvfrom(FileDescriptor fd, ByteBuffer buffer, int flags, InetSocketAddress srcAddress)` See recvfrom(2).
`static int`	`recvmsg(FileDescriptor fd, StructMsghdr msg, int flags)` See recvmsg(2).
`static void`	`remove(String path)` See remove(3).
`static void`	`removexattr(String path, String name)` See removexattr(2).
`static void`	`rename(String oldPath, String newPath)` See rename(2).
`static long`	`sendfile(FileDescriptor outFd, FileDescriptor inFd, Int64Ref offset, long byteCount)` See sendfile(2).
`static int`	`sendmsg(FileDescriptor fd, StructMsghdr msg, int flags)` See sendmsg(2).
`static int`	`sendto(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount, int flags, SocketAddress address)` See sendto(2).
`static int`	`sendto(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount, int flags, InetAddress inetAddress, int port)` See sendto(2).
`static int`	`sendto(FileDescriptor fd, ByteBuffer buffer, int flags, InetAddress inetAddress, int port)` See sendto(2).
`static void`	`setegid(int egid)` This method was deprecated in API level 29. Android Applications do not have sufficient privileges to call this method.
`static void`	`setenv(String name, String value, boolean overwrite)` See setenv(3).
`static void`	`seteuid(int euid)` This method was deprecated in API level 29. Android Applications do not have sufficient privileges to call this method.
`static void`	`setgid(int gid)` This method was deprecated in API level 29. Android Applications do not have sufficient privileges to call this method.
`static int`	`setsid()` See setsid(2).
`static void`	`setsockoptInt(FileDescriptor fd, int level, int option, int value)` See setsockopt(2).
`static void`	`setsockoptTimeval(FileDescriptor fd, int level, int option, StructTimeval value)` See setsockopt(2).
`static void`	`setuid(int uid)` This method was deprecated in API level 29. Android Applications do not have sufficient privileges to call this method.
`static void`	`setxattr(String path, String name, byte[] value, int flags)` See setxattr(2)
`static void`	`shutdown(FileDescriptor fd, int how)` See shutdown(2).
`static FileDescriptor`	`socket(int domain, int type, int protocol)` See socket(2).
`static void`	`socketpair(int domain, int type, int protocol, FileDescriptor fd1, FileDescriptor fd2)` See socketpair(2).
`static StructStat`	`stat(String path)` See stat(2).
`static StructStatVfs`	`statvfs(String path)` See statvfs(2).
`static String`	`strerror(int errno)` See strerror(2).
`static String`	`strsignal(int signal)` See strsignal(3).
`static void`	`symlink(String oldPath, String newPath)` See symlink(2).
`static long`	`sysconf(int name)` See sysconf(3).
`static void`	`tcdrain(FileDescriptor fd)` See tcdrain(3).
`static void`	`tcsendbreak(FileDescriptor fd, int duration)` See tcsendbreak(3).
`static int`	`umask(int mask)` See umask(2).
`static StructUtsname`	`uname()` See uname(2).
`static void`	`unsetenv(String name)` See unsetenv(3).
`static int`	`write(FileDescriptor fd, byte[] bytes, int byteOffset, int byteCount)` See write(2).
`static int`	`write(FileDescriptor fd, ByteBuffer buffer)` See write(2).
`static int`	`writev(FileDescriptor fd, Object[] buffers, int[] offsets, int[] byteCounts)` See writev(2).

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public methods

accept

Added in API level 21

public static FileDescriptor accept (FileDescriptor fd, 
                InetSocketAddress peerAddress)

See accept(2).

Parameters
`fd`	`FileDescriptor`
`peerAddress`	`InetSocketAddress`

Returns
`FileDescriptor`

Throws
`ErrnoException`
`SocketException`

access

Added in API level 21

public static boolean access (String path, 
                int mode)

See access(2).

Parameters
`path`	`String`
`mode`	`int`

Returns
`boolean`

Throws
`ErrnoException`

bind

Added in API level 21

public static void bind (FileDescriptor fd, 
                InetAddress address, 
                int port)

See bind(2).

Parameters
`fd`	`FileDescriptor`
`address`	`InetAddress`
`port`	`int`

Throws
`ErrnoException`
`SocketException`

bind

Added in API level 29

public static void bind (FileDescriptor fd, 
                SocketAddress address)

See bind(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`address`	`SocketAddress`: This value cannot be `null`.

Throws
`ErrnoException`
`SocketException`

chmod

Added in API level 21

public static void chmod (String path, 
                int mode)

See chmod(2).

Parameters
`path`	`String`
`mode`	`int`

Throws
`ErrnoException`

chown

Added in API level 21

public static void chown (String path, 
                int uid, 
                int gid)

See chown(2).

Parameters
`path`	`String`
`uid`	`int`
`gid`	`int`

Throws
`ErrnoException`

close

Added in API level 21

public static void close (FileDescriptor fd)

See close(2).

Parameters
`fd`	`FileDescriptor`

Throws
`ErrnoException`

connect

Added in API level 21

public static void connect (FileDescriptor fd, 
                InetAddress address, 
                int port)

See connect(2).

Parameters
`fd`	`FileDescriptor`
`address`	`InetAddress`
`port`	`int`

Throws
`ErrnoException`
`SocketException`

connect

Added in API level 29

public static void connect (FileDescriptor fd, 
                SocketAddress address)

See connect(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`address`	`SocketAddress`: This value cannot be `null`.

Throws
`ErrnoException`
`SocketException`

dup

Added in API level 21

public static FileDescriptor dup (FileDescriptor oldFd)

See dup(2).

Parameters
`oldFd`	`FileDescriptor`

Returns
`FileDescriptor`

Throws
`ErrnoException`

dup2

Added in API level 21

public static FileDescriptor dup2 (FileDescriptor oldFd, 
                int newFd)

See dup2(2).

Parameters
`oldFd`	`FileDescriptor`
`newFd`	`int`

Returns
`FileDescriptor`

Throws
`ErrnoException`

environ

Added in API level 21

public static String[] environ ()

See environ(3).

Returns
`String[]`

execv

Added in API level 21

public static void execv (String filename, 
                String[] argv)

See exec(3).

Parameters
`filename`	`String`
`argv`	`String`

Throws
`ErrnoException`

execve

Added in API level 21

public static void execve (String filename, 
                String[] argv, 
                String[] envp)

See execve(2).

Parameters
`filename`	`String`
`argv`	`String`
`envp`	`String`

Throws
`ErrnoException`

fchmod

Added in API level 21

public static void fchmod (FileDescriptor fd, 
                int mode)

See fchmod(2).

Parameters
`fd`	`FileDescriptor`
`mode`	`int`

Throws
`ErrnoException`

fchown

Added in API level 21

public static void fchown (FileDescriptor fd, 
                int uid, 
                int gid)

See fchown(2).

Parameters
`fd`	`FileDescriptor`
`uid`	`int`
`gid`	`int`

Throws
`ErrnoException`

fcntlInt

Added in API level 30

public static int fcntlInt (FileDescriptor fd, 
                int cmd, 
                int arg)

See fcntl(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`cmd`	`int`
`arg`	`int`

Returns
`int`

Throws
`ErrnoException`

fdatasync

Added in API level 21

public static void fdatasync (FileDescriptor fd)

See fdatasync(2).

Parameters
`fd`	`FileDescriptor`

Throws
`ErrnoException`

fstat

Added in API level 21

public static StructStat fstat (FileDescriptor fd)

See fstat(2).

Parameters
`fd`	`FileDescriptor`

Returns
`StructStat`

Throws
`ErrnoException`

fstatvfs

Added in API level 21

public static StructStatVfs fstatvfs (FileDescriptor fd)

See fstatvfs(2).

Parameters
`fd`	`FileDescriptor`

Returns
`StructStatVfs`

Throws
`ErrnoException`

fsync

Added in API level 21

public static void fsync (FileDescriptor fd)

See fsync(2).

Parameters
`fd`	`FileDescriptor`

Throws
`ErrnoException`

ftruncate

Added in API level 21

public static void ftruncate (FileDescriptor fd, 
                long length)

See ftruncate(2).

Parameters
`fd`	`FileDescriptor`
`length`	`long`

Throws
`ErrnoException`

gai_strerror

Added in API level 21

public static String gai_strerror (int error)

See gai_strerror(3).

Parameters
`error`	`int`

Returns
`String`

getegid

Added in API level 21

public static int getegid ()

See getegid(2).

Returns
`int`

getenv

Added in API level 21

public static String getenv (String name)

See getenv(3).

Parameters
`name`	`String`

Returns
`String`

geteuid

Added in API level 21

public static int geteuid ()

See geteuid(2).

Returns
`int`

getgid

Added in API level 21

public static int getgid ()

See getgid(2).

Returns
`int`

getpeername

Added in API level 21

public static SocketAddress getpeername (FileDescriptor fd)

See getpeername(2).

Parameters
`fd`	`FileDescriptor`

Returns
`SocketAddress`

Throws
`ErrnoException`

getpid

Added in API level 21

public static int getpid ()

See getpid(2).

Returns
`int`

getppid

Added in API level 21

public static int getppid ()

See getppid(2).

Returns
`int`

getsockname

Added in API level 21

public static SocketAddress getsockname (FileDescriptor fd)

See getsockname(2).

Parameters
`fd`	`FileDescriptor`

Returns
`SocketAddress`

Throws
`ErrnoException`

getsockoptTimeval

Added in API level 29

public static StructTimeval getsockoptTimeval (FileDescriptor fd, 
                int level, 
                int option)

See getsockopt(2).

Only for use with option values that return a struct timeval such as OsConstants.SO_RCVTIMEO and OsConstants.SO_SNDTIMEO. Use with other options may throw an IllegalArgumentException or return junk values.

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`level`	`int`
`option`	`int`

Returns
`StructTimeval`	This value cannot be `null`.

Throws
`ErrnoException`

gettid

Added in API level 21

public static int gettid ()

See gettid(2).

Returns
`int`

getuid

Added in API level 21

public static int getuid ()

See getuid(2).

Returns
`int`

getxattr

Added in API level 26

public static byte[] getxattr (String path, 
                String name)

See getxattr(2)

Parameters
`path`	`String`
`name`	`String`

Returns
`byte[]`

Throws
`ErrnoException`

if_indextoname

Added in API level 21

public static String if_indextoname (int index)

See if_indextoname(3).

Parameters
`index`	`int`

Returns
`String`

if_nametoindex

Added in API level 26

public static int if_nametoindex (String name)

See if_nametoindex(3).

Parameters
`name`	`String`

Returns
`int`

inet_pton

Added in API level 21

public static InetAddress inet_pton (int family, 
                String address)

See inet_pton(3).

Parameters
`family`	`int`
`address`	`String`

Returns
`InetAddress`

isatty

Added in API level 21

public static boolean isatty (FileDescriptor fd)

See isatty(3).

Parameters
`fd`	`FileDescriptor`

Returns
`boolean`

kill

Added in API level 21

public static void kill (int pid, 
                int signal)

See kill(2).

Parameters
`pid`	`int`
`signal`	`int`

Throws
`ErrnoException`

lchown

Added in API level 21

public static void lchown (String path, 
                int uid, 
                int gid)

See lchown(2).

Parameters
`path`	`String`
`uid`	`int`
`gid`	`int`

Throws
`ErrnoException`

link

Added in API level 21

public static void link (String oldPath, 
                String newPath)

See link(2).

Parameters
`oldPath`	`String`
`newPath`	`String`

Throws
`ErrnoException`

listen

Added in API level 21

public static void listen (FileDescriptor fd, 
                int backlog)

See listen(2).

Parameters
`fd`	`FileDescriptor`
`backlog`	`int`

Throws
`ErrnoException`

listxattr

Added in API level 26

public static String[] listxattr (String path)

See listxattr(2)

Parameters
`path`	`String`

Returns
`String[]`

Throws
`ErrnoException`

lseek

Added in API level 21

public static long lseek (FileDescriptor fd, 
                long offset, 
                int whence)

See lseek(2).

Parameters
`fd`	`FileDescriptor`
`offset`	`long`
`whence`	`int`

Returns
`long`

Throws
`ErrnoException`

lstat

Added in API level 21

public static StructStat lstat (String path)

See lstat(2).

Parameters
`path`	`String`

Returns
`StructStat`

Throws
`ErrnoException`

memfd_create

Added in API level 30

public static FileDescriptor memfd_create (String name, 
                int flags)

See memfd_create(2).

Parameters
`name`	`String`: This value cannot be `null`.
`flags`	`int`

Returns
`FileDescriptor`	This value cannot be `null`.

Throws
`ErrnoException`

mincore

Added in API level 21

public static void mincore (long address, 
                long byteCount, 
                byte[] vector)

See mincore(2).

Parameters
`address`	`long`
`byteCount`	`long`
`vector`	`byte`

Throws
`ErrnoException`

mkdir

Added in API level 21

public static void mkdir (String path, 
                int mode)

See mkdir(2).

Parameters
`path`	`String`
`mode`	`int`

Throws
`ErrnoException`

mkfifo

Added in API level 21

public static void mkfifo (String path, 
                int mode)

See mkfifo(3).

Parameters
`path`	`String`
`mode`	`int`

Throws
`ErrnoException`

mlock

Added in API level 21

public static void mlock (long address, 
                long byteCount)

See mlock(2).

Parameters
`address`	`long`
`byteCount`	`long`

Throws
`ErrnoException`

mmap

Added in API level 21

public static long mmap (long address, 
                long byteCount, 
                int prot, 
                int flags, 
                FileDescriptor fd, 
                long offset)

See mmap(2).

Parameters
`address`	`long`
`byteCount`	`long`
`prot`	`int`
`flags`	`int`
`fd`	`FileDescriptor`
`offset`	`long`

Returns
`long`

Throws
`ErrnoException`

msync

Added in API level 21

public static void msync (long address, 
                long byteCount, 
                int flags)

See msync(2).

Parameters
`address`	`long`
`byteCount`	`long`
`flags`	`int`

Throws
`ErrnoException`

munlock

Added in API level 21

public static void munlock (long address, 
                long byteCount)

See munlock(2).

Parameters
`address`	`long`
`byteCount`	`long`

Throws
`ErrnoException`

munmap

Added in API level 21

public static void munmap (long address, 
                long byteCount)

See munmap(2).

Parameters
`address`	`long`
`byteCount`	`long`

Throws
`ErrnoException`

open

Added in API level 21

public static FileDescriptor open (String path, 
                int flags, 
                int mode)

See open(2).

Parameters
`path`	`String`
`flags`	`int`
`mode`	`int`

Returns
`FileDescriptor`

Throws
`ErrnoException`

pipe

Added in API level 21

public static FileDescriptor[] pipe ()

See pipe(2).

Returns
`FileDescriptor[]`

Throws
`ErrnoException`

poll

Added in API level 21

public static int poll (StructPollfd[] fds, 
                int timeoutMs)

See poll(2).

Note that in Lollipop this could throw an ErrnoException with EINTR. In later releases, the implementation will automatically just restart the system call with an appropriately reduced timeout.

Parameters
`fds`	`StructPollfd`
`timeoutMs`	`int`

Returns
`int`

Throws
`ErrnoException`

posix_fallocate

Added in API level 21

public static void posix_fallocate (FileDescriptor fd, 
                long offset, 
                long length)

See posix_fallocate(3).

Parameters
`fd`	`FileDescriptor`
`offset`	`long`
`length`	`long`

Throws
`ErrnoException`

prctl

Added in API level 21

public static int prctl (int option, 
                long arg2, 
                long arg3, 
                long arg4, 
                long arg5)

See prctl(2).

Parameters
`option`	`int`
`arg2`	`long`
`arg3`	`long`
`arg4`	`long`
`arg5`	`long`

Returns
`int`

Throws
`ErrnoException`

pread

Added in API level 21

public static int pread (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount, 
                long offset)

See pread(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`
`offset`	`long`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

pread

Added in API level 21

public static int pread (FileDescriptor fd, 
                ByteBuffer buffer, 
                long offset)

See pread(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`
`offset`	`long`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

pwrite

Added in API level 21

public static int pwrite (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount, 
                long offset)

See pwrite(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`
`offset`	`long`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

pwrite

Added in API level 21

public static int pwrite (FileDescriptor fd, 
                ByteBuffer buffer, 
                long offset)

See pwrite(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`
`offset`	`long`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

read

Added in API level 21

public static int read (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount)

See read(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

read

Added in API level 21

public static int read (FileDescriptor fd, 
                ByteBuffer buffer)

See read(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

readlink

Added in API level 21

public static String readlink (String path)

See readlink(2).

Parameters
`path`	`String`

Returns
`String`

Throws
`ErrnoException`

readv

Added in API level 21

public static int readv (FileDescriptor fd, 
                Object[] buffers, 
                int[] offsets, 
                int[] byteCounts)

See readv(2).

Parameters
`fd`	`FileDescriptor`
`buffers`	`Object`
`offsets`	`int`
`byteCounts`	`int`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

recvfrom

Added in API level 21

public static int recvfrom (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount, 
                int flags, 
                InetSocketAddress srcAddress)

See recvfrom(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`
`flags`	`int`
`srcAddress`	`InetSocketAddress`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

recvfrom

Added in API level 21

public static int recvfrom (FileDescriptor fd, 
                ByteBuffer buffer, 
                int flags, 
                InetSocketAddress srcAddress)

See recvfrom(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`
`flags`	`int`
`srcAddress`	`InetSocketAddress`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

recvmsg

Added in API level 31

public static int recvmsg (FileDescriptor fd, 
                StructMsghdr msg, 
                int flags)

See recvmsg(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`msg`	`StructMsghdr`: This value cannot be `null`.
`flags`	`int`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

remove

Added in API level 21

public static void remove (String path)

See remove(3).

Parameters
`path`	`String`

Throws
`ErrnoException`

removexattr

Added in API level 26

public static void removexattr (String path, 
                String name)

See removexattr(2).

Parameters
`path`	`String`
`name`	`String`

Throws
`ErrnoException`

rename

Added in API level 21

public static void rename (String oldPath, 
                String newPath)

See rename(2).

Parameters
`oldPath`	`String`
`newPath`	`String`

Throws
`ErrnoException`

sendfile

Added in API level 28

public static long sendfile (FileDescriptor outFd, 
                FileDescriptor inFd, 
                Int64Ref offset, 
                long byteCount)

See sendfile(2).

Parameters
`outFd`	`FileDescriptor`
`inFd`	`FileDescriptor`
`offset`	`Int64Ref`
`byteCount`	`long`

Returns
`long`

Throws
`ErrnoException`

sendmsg

Added in API level 31

public static int sendmsg (FileDescriptor fd, 
                StructMsghdr msg, 
                int flags)

See sendmsg(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`msg`	`StructMsghdr`: This value cannot be `null`.
`flags`	`int`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

sendto

Added in API level 29

public static int sendto (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount, 
                int flags, 
                SocketAddress address)

See sendto(2).

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`bytes`	`byte`: This value cannot be `null`.
`byteOffset`	`int`
`byteCount`	`int`
`flags`	`int`
`address`	`SocketAddress`: This value may be `null`.

Returns
`int`

Throws
`ErrnoException`
`SocketException`

sendto

Added in API level 21

public static int sendto (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount, 
                int flags, 
                InetAddress inetAddress, 
                int port)

See sendto(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`
`flags`	`int`
`inetAddress`	`InetAddress`
`port`	`int`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

sendto

Added in API level 21

public static int sendto (FileDescriptor fd, 
                ByteBuffer buffer, 
                int flags, 
                InetAddress inetAddress, 
                int port)

See sendto(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`
`flags`	`int`
`inetAddress`	`InetAddress`
`port`	`int`

Returns
`int`

Throws
`ErrnoException`
`SocketException`

setegid

Added in API level 21
Deprecated in API level 29

public static void setegid (int egid)

This method was deprecated in API level 29.
Android Applications do not have sufficient privileges to call this method.

See setegid(2).

Parameters
`egid`	`int`

Throws
`ErrnoException`

setenv

Added in API level 21

public static void setenv (String name, 
                String value, 
                boolean overwrite)

See setenv(3).

Parameters
`name`	`String`
`value`	`String`
`overwrite`	`boolean`

Throws
`ErrnoException`

seteuid

Added in API level 21
Deprecated in API level 29

public static void seteuid (int euid)

This method was deprecated in API level 29.
Android Applications do not have sufficient privileges to call this method.

See seteuid(2).

Parameters
`euid`	`int`

Throws
`ErrnoException`

setgid

Added in API level 21
Deprecated in API level 29

public static void setgid (int gid)

This method was deprecated in API level 29.
Android Applications do not have sufficient privileges to call this method.

See setgid(2).

Parameters
`gid`	`int`

Throws
`ErrnoException`

setsid

Added in API level 21

public static int setsid ()

See setsid(2).

Returns
`int`

Throws
`ErrnoException`

setsockoptInt

Added in API level 26

public static void setsockoptInt (FileDescriptor fd, 
                int level, 
                int option, 
                int value)

See setsockopt(2).

Parameters
`fd`	`FileDescriptor`
`level`	`int`
`option`	`int`
`value`	`int`

Throws
`ErrnoException`

setsockoptTimeval

Added in API level 29

public static void setsockoptTimeval (FileDescriptor fd, 
                int level, 
                int option, 
                StructTimeval value)

See setsockopt(2).

Only for use with option values that take a struct timeval such as OsConstants.SO_RCVTIMEO and OsConstants.SO_SNDTIMEO. Use with other options is likely to cause incorrect behavior.

Parameters
`fd`	`FileDescriptor`: This value cannot be `null`.
`level`	`int`
`option`	`int`
`value`	`StructTimeval`: This value cannot be `null`.

Throws
`ErrnoException`

setuid

Added in API level 21
Deprecated in API level 29

public static void setuid (int uid)

This method was deprecated in API level 29.
Android Applications do not have sufficient privileges to call this method.

See setuid(2).

Parameters
`uid`	`int`

Throws
`ErrnoException`

setxattr

Added in API level 26

public static void setxattr (String path, 
                String name, 
                byte[] value, 
                int flags)

See setxattr(2)

Parameters
`path`	`String`
`name`	`String`
`value`	`byte`
`flags`	`int`

Throws
`ErrnoException`

shutdown

Added in API level 21

public static void shutdown (FileDescriptor fd, 
                int how)

See shutdown(2).

Parameters
`fd`	`FileDescriptor`
`how`	`int`

Throws
`ErrnoException`

socket

Added in API level 21

public static FileDescriptor socket (int domain, 
                int type, 
                int protocol)

See socket(2).

Parameters
`domain`	`int`
`type`	`int`
`protocol`	`int`

Returns
`FileDescriptor`

Throws
`ErrnoException`

socketpair

Added in API level 21

public static void socketpair (int domain, 
                int type, 
                int protocol, 
                FileDescriptor fd1, 
                FileDescriptor fd2)

See socketpair(2).

Parameters
`domain`	`int`
`type`	`int`
`protocol`	`int`
`fd1`	`FileDescriptor`
`fd2`	`FileDescriptor`

Throws
`ErrnoException`

stat

Added in API level 21

public static StructStat stat (String path)

See stat(2).

Parameters
`path`	`String`

Returns
`StructStat`

Throws
`ErrnoException`

statvfs

Added in API level 21

public static StructStatVfs statvfs (String path)

See statvfs(2).

Parameters
`path`	`String`

Returns
`StructStatVfs`

Throws
`ErrnoException`

strerror

Added in API level 21

public static String strerror (int errno)

See strerror(2).

Parameters
`errno`	`int`

Returns
`String`

strsignal

Added in API level 21

public static String strsignal (int signal)

See strsignal(3).

Parameters
`signal`	`int`

Returns
`String`

symlink

Added in API level 21

public static void symlink (String oldPath, 
                String newPath)

See symlink(2).

Parameters
`oldPath`	`String`
`newPath`	`String`

Throws
`ErrnoException`

sysconf

Added in API level 21

public static long sysconf (int name)

See sysconf(3).

Parameters
`name`	`int`

Returns
`long`

tcdrain

Added in API level 21

public static void tcdrain (FileDescriptor fd)

See tcdrain(3).

Parameters
`fd`	`FileDescriptor`

Throws
`ErrnoException`

tcsendbreak

Added in API level 21

public static void tcsendbreak (FileDescriptor fd, 
                int duration)

See tcsendbreak(3).

Parameters
`fd`	`FileDescriptor`
`duration`	`int`

Throws
`ErrnoException`

umask

Added in API level 21

public static int umask (int mask)

See umask(2).

Parameters
`mask`	`int`

Returns
`int`

uname

Added in API level 21

public static StructUtsname uname ()

See uname(2).

Returns
`StructUtsname`

unsetenv

Added in API level 21

public static void unsetenv (String name)

See unsetenv(3).

Parameters
`name`	`String`

Throws
`ErrnoException`

write

Added in API level 21

public static int write (FileDescriptor fd, 
                byte[] bytes, 
                int byteOffset, 
                int byteCount)

See write(2).

Parameters
`fd`	`FileDescriptor`
`bytes`	`byte`
`byteOffset`	`int`
`byteCount`	`int`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

write

Added in API level 21

public static int write (FileDescriptor fd, 
                ByteBuffer buffer)

See write(2).

Parameters
`fd`	`FileDescriptor`
`buffer`	`ByteBuffer`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`

writev

Added in API level 21

public static int writev (FileDescriptor fd, 
                Object[] buffers, 
                int[] offsets, 
                int[] byteCounts)

See writev(2).

Parameters
`fd`	`FileDescriptor`
`buffers`	`Object`
`offsets`	`int`
`byteCounts`	`int`

Returns
`int`

Throws
`ErrnoException`
`InterruptedIOException`