Types

<a href="#size" name="size"></a> size: u32

Size: 4
Alignment: 4

<a href="#filesize" name="filesize"></a> filesize: u64

Non-negative file size or length of a region within a file.
Size: 8
Alignment: 8

<a href="#timestamp" name="timestamp"></a> timestamp: u64

Timestamp in nanoseconds.
Size: 8
Alignment: 8

<a href="#clockid" name="clockid"></a> clockid: Enum(u32)

Identifiers for clocks.
Size: 4
Alignment: 4

Variants

• <a href="#clockid.realtime" name="clockid.realtime"></a> realtime
  The clock measuring real time. Time value zero corresponds with
  1970-01-01T00:00:00Z.

• <a href="#clockid.monotonic" name="clockid.monotonic"></a> monotonic
  The store-wide monotonic clock, which is defined as a clock measuring
  real time, whose value cannot be adjusted and which cannot have negative
  clock jumps. The epoch of this clock is undefined. The absolute time
  value of this clock therefore has no meaning.

• <a href="#clockid.process_cputime_id" name="clockid.process_cputime_id"></a> process_cputime_id
  The CPU-time clock associated with the current process.

• <a href="#clockid.thread_cputime_id" name="clockid.thread_cputime_id"></a> thread_cputime_id
  The CPU-time clock associated with the current thread.

<a href="#errno" name="errno"></a> errno: Enum(u16)

Error codes returned by functions.
Not all of these error codes are returned by the functions provided by this
API; some are used in higher-level library layers, and others are provided
merely for alignment with POSIX.
Size: 2
Alignment: 2

Variants

• <a href="#errno.success" name="errno.success"></a> success
  No error occurred. System call completed successfully.

• <a href="#errno.2big" name="errno.2big"></a> 2big
  Argument list too long.

• <a href="#errno.acces" name="errno.acces"></a> acces
  Permission denied.

• <a href="#errno.addrinuse" name="errno.addrinuse"></a> addrinuse
  Address in use.

• <a href="#errno.addrnotavail" name="errno.addrnotavail"></a> addrnotavail
  Address not available.

• <a href="#errno.afnosupport" name="errno.afnosupport"></a> afnosupport
  Address family not supported.

• <a href="#errno.again" name="errno.again"></a> again
  Resource unavailable, or operation would block.

• <a href="#errno.already" name="errno.already"></a> already
  Connection already in progress.

• <a href="#errno.badf" name="errno.badf"></a> badf
  Bad file descriptor.

• <a href="#errno.badmsg" name="errno.badmsg"></a> badmsg
  Bad message.

• <a href="#errno.busy" name="errno.busy"></a> busy
  Device or resource busy.

• <a href="#errno.canceled" name="errno.canceled"></a> canceled
  Operation canceled.

• <a href="#errno.child" name="errno.child"></a> child
  No child processes.

• <a href="#errno.connaborted" name="errno.connaborted"></a> connaborted
  Connection aborted.

• <a href="#errno.connrefused" name="errno.connrefused"></a> connrefused
  Connection refused.

• <a href="#errno.connreset" name="errno.connreset"></a> connreset
  Connection reset.

• <a href="#errno.deadlk" name="errno.deadlk"></a> deadlk
  Resource deadlock would occur.

• <a href="#errno.destaddrreq" name="errno.destaddrreq"></a> destaddrreq
  Destination address required.

• <a href="#errno.dom" name="errno.dom"></a> dom
  Mathematics argument out of domain of function.

• <a href="#errno.dquot" name="errno.dquot"></a> dquot
  Reserved.

• <a href="#errno.exist" name="errno.exist"></a> exist
  File exists.

• <a href="#errno.fault" name="errno.fault"></a> fault
  Bad address.

• <a href="#errno.fbig" name="errno.fbig"></a> fbig
  File too large.

• <a href="#errno.hostunreach" name="errno.hostunreach"></a> hostunreach
  Host is unreachable.

• <a href="#errno.idrm" name="errno.idrm"></a> idrm
  Identifier removed.

• <a href="#errno.ilseq" name="errno.ilseq"></a> ilseq
  Illegal byte sequence.

• <a href="#errno.inprogress" name="errno.inprogress"></a> inprogress
  Operation in progress.

• <a href="#errno.intr" name="errno.intr"></a> intr
  Interrupted function.

• <a href="#errno.inval" name="errno.inval"></a> inval
  Invalid argument.

• <a href="#errno.io" name="errno.io"></a> io
  I/O error.

• <a href="#errno.isconn" name="errno.isconn"></a> isconn
  Socket is connected.

• <a href="#errno.isdir" name="errno.isdir"></a> isdir
  Is a directory.

• <a href="#errno.loop" name="errno.loop"></a> loop
  Too many levels of symbolic links.

• <a href="#errno.mfile" name="errno.mfile"></a> mfile
  File descriptor value too large.

• <a href="#errno.mlink" name="errno.mlink"></a> mlink
  Too many links.

• <a href="#errno.msgsize" name="errno.msgsize"></a> msgsize
  Message too large.

• <a href="#errno.multihop" name="errno.multihop"></a> multihop
  Reserved.

• <a href="#errno.nametoolong" name="errno.nametoolong"></a> nametoolong
  Filename too long.

• <a href="#errno.netdown" name="errno.netdown"></a> netdown
  Network is down.

• <a href="#errno.netreset" name="errno.netreset"></a> netreset
  Connection aborted by network.

• <a href="#errno.netunreach" name="errno.netunreach"></a> netunreach
  Network unreachable.

• <a href="#errno.nfile" name="errno.nfile"></a> nfile
  Too many files open in system.

• <a href="#errno.nobufs" name="errno.nobufs"></a> nobufs
  No buffer space available.

• <a href="#errno.nodev" name="errno.nodev"></a> nodev
  No such device.

• <a href="#errno.noent" name="errno.noent"></a> noent
  No such file or directory.

• <a href="#errno.noexec" name="errno.noexec"></a> noexec
  Executable file format error.

• <a href="#errno.nolck" name="errno.nolck"></a> nolck
  No locks available.

• <a href="#errno.nolink" name="errno.nolink"></a> nolink
  Reserved.

• <a href="#errno.nomem" name="errno.nomem"></a> nomem
  Not enough space.

• <a href="#errno.nomsg" name="errno.nomsg"></a> nomsg
  No message of the desired type.

• <a href="#errno.noprotoopt" name="errno.noprotoopt"></a> noprotoopt
  Protocol not available.

• <a href="#errno.nospc" name="errno.nospc"></a> nospc
  No space left on device.

• <a href="#errno.nosys" name="errno.nosys"></a> nosys
  Function not supported.

• <a href="#errno.notconn" name="errno.notconn"></a> notconn
  The socket is not connected.

• <a href="#errno.notdir" name="errno.notdir"></a> notdir
  Not a directory or a symbolic link to a directory.

• <a href="#errno.notempty" name="errno.notempty"></a> notempty
  Directory not empty.

• <a href="#errno.notrecoverable" name="errno.notrecoverable"></a> notrecoverable
  State not recoverable.

• <a href="#errno.notsock" name="errno.notsock"></a> notsock
  Not a socket.

• <a href="#errno.notsup" name="errno.notsup"></a> notsup
  Not supported, or operation not supported on socket.

• <a href="#errno.notty" name="errno.notty"></a> notty
  Inappropriate I/O control operation.

• <a href="#errno.nxio" name="errno.nxio"></a> nxio
  No such device or address.

• <a href="#errno.overflow" name="errno.overflow"></a> overflow
  Value too large to be stored in data type.

• <a href="#errno.ownerdead" name="errno.ownerdead"></a> ownerdead
  Previous owner died.

• <a href="#errno.perm" name="errno.perm"></a> perm
  Operation not permitted.

• <a href="#errno.pipe" name="errno.pipe"></a> pipe
  Broken pipe.

• <a href="#errno.proto" name="errno.proto"></a> proto
  Protocol error.

• <a href="#errno.protonosupport" name="errno.protonosupport"></a> protonosupport
  Protocol not supported.

• <a href="#errno.prototype" name="errno.prototype"></a> prototype
  Protocol wrong type for socket.

• <a href="#errno.range" name="errno.range"></a> range
  Result too large.

• <a href="#errno.rofs" name="errno.rofs"></a> rofs
  Read-only file system.

• <a href="#errno.spipe" name="errno.spipe"></a> spipe
  Invalid seek.

• <a href="#errno.srch" name="errno.srch"></a> srch
  No such process.

• <a href="#errno.stale" name="errno.stale"></a> stale
  Reserved.

• <a href="#errno.timedout" name="errno.timedout"></a> timedout
  Connection timed out.

• <a href="#errno.txtbsy" name="errno.txtbsy"></a> txtbsy
  Text file busy.

• <a href="#errno.xdev" name="errno.xdev"></a> xdev
  Cross-device link.

• <a href="#errno.notcapable" name="errno.notcapable"></a> notcapable
  Extension: Capabilities insufficient.

<a href="#rights" name="rights"></a> rights: Flags(u64)

File descriptor rights, determining which actions may be performed.
Size: 8
Alignment: 8

Flags

• <a href="#rights.fd_datasync" name="rights.fd_datasync"></a> fd_datasync
  The right to invoke fd_datasync.
  If path_open is set, includes the right to invoke
  path_open with fdflags::dsync.

• <a href="#rights.fd_read" name="rights.fd_read"></a> fd_read
  The right to invoke fd_read and sock_recv.
  If rights::fd_seek is set, includes the right to invoke fd_pread.

• <a href="#rights.fd_seek" name="rights.fd_seek"></a> fd_seek
  The right to invoke fd_seek. This flag implies rights::fd_tell.

• <a href="#rights.fd_fdstat_set_flags" name="rights.fd_fdstat_set_flags"></a> fd_fdstat_set_flags
  The right to invoke fd_fdstat_set_flags.

• <a href="#rights.fd_sync" name="rights.fd_sync"></a> fd_sync
  The right to invoke fd_sync.
  If path_open is set, includes the right to invoke
  path_open with fdflags::rsync and fdflags::dsync.

• <a href="#rights.fd_tell" name="rights.fd_tell"></a> fd_tell
  The right to invoke fd_seek in such a way that the file offset
  remains unaltered (i.e., whence::cur with offset zero), or to
  invoke fd_tell.

• <a href="#rights.fd_write" name="rights.fd_write"></a> fd_write
  The right to invoke fd_write and sock_send.
  If rights::fd_seek is set, includes the right to invoke fd_pwrite.

• <a href="#rights.fd_advise" name="rights.fd_advise"></a> fd_advise
  The right to invoke fd_advise.

• <a href="#rights.fd_allocate" name="rights.fd_allocate"></a> fd_allocate
  The right to invoke fd_allocate.

• <a href="#rights.path_create_directory" name="rights.path_create_directory"></a> path_create_directory
  The right to invoke path_create_directory.

• <a href="#rights.path_create_file" name="rights.path_create_file"></a> path_create_file
  If path_open is set, the right to invoke path_open with oflags::creat.

• <a href="#rights.path_link_source" name="rights.path_link_source"></a> path_link_source
  The right to invoke path_link with the file descriptor as the
  source directory.

• <a href="#rights.path_link_target" name="rights.path_link_target"></a> path_link_target
  The right to invoke path_link with the file descriptor as the
  target directory.

• <a href="#rights.path_open" name="rights.path_open"></a> path_open
  The right to invoke path_open.

• <a href="#rights.fd_readdir" name="rights.fd_readdir"></a> fd_readdir
  The right to invoke fd_readdir.

• <a href="#rights.path_readlink" name="rights.path_readlink"></a> path_readlink
  The right to invoke path_readlink.

• <a href="#rights.path_rename_source" name="rights.path_rename_source"></a> path_rename_source
  The right to invoke path_rename with the file descriptor as the source directory.

• <a href="#rights.path_rename_target" name="rights.path_rename_target"></a> path_rename_target
  The right to invoke path_rename with the file descriptor as the target directory.

• <a href="#rights.path_filestat_get" name="rights.path_filestat_get"></a> path_filestat_get
  The right to invoke path_filestat_get.

• <a href="#rights.path_filestat_set_size" name="rights.path_filestat_set_size"></a> path_filestat_set_size
  The right to change a file's size (there is no path_filestat_set_size).
  If path_open is set, includes the right to invoke path_open with oflags::trunc.

• <a href="#rights.path_filestat_set_times" name="rights.path_filestat_set_times"></a> path_filestat_set_times
  The right to invoke path_filestat_set_times.

• <a href="#rights.fd_filestat_get" name="rights.fd_filestat_get"></a> fd_filestat_get
  The right to invoke fd_filestat_get.

• <a href="#rights.fd_filestat_set_size" name="rights.fd_filestat_set_size"></a> fd_filestat_set_size
  The right to invoke fd_filestat_set_size.

• <a href="#rights.fd_filestat_set_times" name="rights.fd_filestat_set_times"></a> fd_filestat_set_times
  The right to invoke fd_filestat_set_times.

• <a href="#rights.path_symlink" name="rights.path_symlink"></a> path_symlink
  The right to invoke path_symlink.

• <a href="#rights.path_remove_directory" name="rights.path_remove_directory"></a> path_remove_directory
  The right to invoke path_remove_directory.

• <a href="#rights.path_unlink_file" name="rights.path_unlink_file"></a> path_unlink_file
  The right to invoke path_unlink_file.

• <a href="#rights.poll_fd_readwrite" name="rights.poll_fd_readwrite"></a> poll_fd_readwrite
  If rights::fd_read is set, includes the right to invoke poll_oneoff to subscribe to eventtype::fd_read.
  If rights::fd_write is set, includes the right to invoke poll_oneoff to subscribe to eventtype::fd_write.

• <a href="#rights.sock_shutdown" name="rights.sock_shutdown"></a> sock_shutdown
  The right to invoke sock_shutdown.

<a href="#fd" name="fd"></a> fd

A file descriptor handle.
Size: 4
Alignment: 4

Supertypes

<a href="#iovec" name="iovec"></a> iovec: Struct

A region of memory for scatter/gather reads.
Size: 8
Alignment: 4

Struct members

• <a href="#iovec.buf" name="iovec.buf"></a> buf: Pointer<u8>
  The address of the buffer to be filled.
  Offset: 0
• <a href="#iovec.buf_len" name="iovec.buf_len"></a> buf_len: size
  The length of the buffer to be filled.
  Offset: 4

  <a href="#ciovec" name="ciovec"></a> ciovec: Struct

  A region of memory for scatter/gather writes.
  Size: 8
  Alignment: 4

  Struct members

• <a href="#ciovec.buf" name="ciovec.buf"></a> buf: ConstPointer<u8>
  The address of the buffer to be written.
  Offset: 0
• <a href="#ciovec.buf_len" name="ciovec.buf_len"></a> buf_len: size
  The length of the buffer to be written.
  Offset: 4

  <a href="#iovec_array" name="iovec_array"></a> iovec_array: Array<iovec>

  Size: 8
  Alignment: 4

  <a href="#ciovec_array" name="ciovec_array"></a> ciovec_array: Array<ciovec>

  Size: 8
  Alignment: 4

  <a href="#filedelta" name="filedelta"></a> filedelta: s64

  Relative offset within a file.
  Size: 8
  Alignment: 8

  <a href="#whence" name="whence"></a> whence: Enum(u8)

  The position relative to which to set the offset of the file descriptor.
  Size: 1
  Alignment: 1

  Variants

• <a href="#whence.set" name="whence.set"></a> set
  Seek relative to start-of-file.

• <a href="#whence.cur" name="whence.cur"></a> cur
  Seek relative to current position.

• <a href="#whence.end" name="whence.end"></a> end
  Seek relative to end-of-file.

<a href="#dircookie" name="dircookie"></a> dircookie: u64

A reference to the offset of a directory entry.

The value 0 signifies the start of the directory.
Size: 8
Alignment: 8

<a href="#dirnamlen" name="dirnamlen"></a> dirnamlen: u32

The type for the $d_namlen field of $dirent.
Size: 4
Alignment: 4

<a href="#inode" name="inode"></a> inode: u64

File serial number that is unique within its file system.
Size: 8
Alignment: 8

<a href="#filetype" name="filetype"></a> filetype: Enum(u8)

The type of a file descriptor or file.
Size: 1
Alignment: 1

Variants

• <a href="#filetype.unknown" name="filetype.unknown"></a> unknown
  The type of the file descriptor or file is unknown or is different from any of the other types specified.

• <a href="#filetype.block_device" name="filetype.block_device"></a> block_device
  The file descriptor or file refers to a block device inode.

• <a href="#filetype.character_device" name="filetype.character_device"></a> character_device
  The file descriptor or file refers to a character device inode.

• <a href="#filetype.directory" name="filetype.directory"></a> directory
  The file descriptor or file refers to a directory inode.

• <a href="#filetype.regular_file" name="filetype.regular_file"></a> regular_file
  The file descriptor or file refers to a regular file inode.

• <a href="#filetype.socket_dgram" name="filetype.socket_dgram"></a> socket_dgram
  The file descriptor or file refers to a datagram socket.

• <a href="#filetype.socket_stream" name="filetype.socket_stream"></a> socket_stream
  The file descriptor or file refers to a byte-stream socket.

• <a href="#filetype.symbolic_link" name="filetype.symbolic_link"></a> symbolic_link
  The file refers to a symbolic link inode.

<a href="#dirent" name="dirent"></a> dirent: Struct

A directory entry.
Size: 24
Alignment: 8

Struct members

• <a href="#dirent.d_next" name="dirent.d_next"></a> d_next: dircookie
  The offset of the next directory entry stored in this directory.
  Offset: 0
• <a href="#dirent.d_ino" name="dirent.d_ino"></a> d_ino: inode
  The serial number of the file referred to by this directory entry.
  Offset: 8
• <a href="#dirent.d_namlen" name="dirent.d_namlen"></a> d_namlen: dirnamlen
  The length of the name of the directory entry.
  Offset: 16
• <a href="#dirent.d_type" name="dirent.d_type"></a> d_type: filetype
  The type of the file referred to by this directory entry.
  Offset: 20

  <a href="#advice" name="advice"></a> advice: Enum(u8)

  File or memory access pattern advisory information.
  Size: 1
  Alignment: 1

  Variants

• <a href="#advice.normal" name="advice.normal"></a> normal
  The application has no advice to give on its behavior with respect to the specified data.

• <a href="#advice.sequential" name="advice.sequential"></a> sequential
  The application expects to access the specified data sequentially from lower offsets to higher offsets.

• <a href="#advice.random" name="advice.random"></a> random
  The application expects to access the specified data in a random order.

• <a href="#advice.willneed" name="advice.willneed"></a> willneed
  The application expects to access the specified data in the near future.

• <a href="#advice.dontneed" name="advice.dontneed"></a> dontneed
  The application expects that it will not access the specified data in the near future.

• <a href="#advice.noreuse" name="advice.noreuse"></a> noreuse
  The application expects to access the specified data once and then not reuse it thereafter.

<a href="#fdflags" name="fdflags"></a> fdflags: Flags(u16)

File descriptor flags.
Size: 2
Alignment: 2

Flags

• <a href="#fdflags.append" name="fdflags.append"></a> append
  Append mode: Data written to the file is always appended to the file's end.

• <a href="#fdflags.dsync" name="fdflags.dsync"></a> dsync
  Write according to synchronized I/O data integrity completion. Only the data stored in the file is synchronized.

• <a href="#fdflags.nonblock" name="fdflags.nonblock"></a> nonblock
  Non-blocking mode.

• <a href="#fdflags.rsync" name="fdflags.rsync"></a> rsync
  Synchronized read I/O operations.

• <a href="#fdflags.sync" name="fdflags.sync"></a> sync
  Write according to synchronized I/O file integrity completion. In
  addition to synchronizing the data stored in the file, the implementation
  may also synchronously update the file's metadata.

<a href="#fdstat" name="fdstat"></a> fdstat: Struct

File descriptor attributes.
Size: 24
Alignment: 8

Struct members

• <a href="#fdstat.fs_filetype" name="fdstat.fs_filetype"></a> fs_filetype: filetype
  File type.
  Offset: 0
• <a href="#fdstat.fs_flags" name="fdstat.fs_flags"></a> fs_flags: fdflags
  File descriptor flags.
  Offset: 2
• <a href="#fdstat.fs_rights_base" name="fdstat.fs_rights_base"></a> fs_rights_base: rights
  Rights that apply to this file descriptor.
  Offset: 8
• <a href="#fdstat.fs_rights_inheriting" name="fdstat.fs_rights_inheriting"></a> fs_rights_inheriting: rights
  Maximum set of rights that may be installed on new file descriptors that
  are created through this file descriptor, e.g., through path_open.
  Offset: 16

  <a href="#device" name="device"></a> device: u64

  Identifier for a device containing a file system. Can be used in combination
  with inode to uniquely identify a file or directory in the filesystem.
  Size: 8
  Alignment: 8

  <a href="#fstflags" name="fstflags"></a> fstflags: Flags(u16)

  Which file time attributes to adjust.
  Size: 2
  Alignment: 2

  Flags

• <a href="#fstflags.atim" name="fstflags.atim"></a> atim
  Adjust the last data access timestamp to the value stored in filestat::atim.

• <a href="#fstflags.atim_now" name="fstflags.atim_now"></a> atim_now
  Adjust the last data access timestamp to the time of clock clockid::realtime.

• <a href="#fstflags.mtim" name="fstflags.mtim"></a> mtim
  Adjust the last data modification timestamp to the value stored in filestat::mtim.

• <a href="#fstflags.mtim_now" name="fstflags.mtim_now"></a> mtim_now
  Adjust the last data modification timestamp to the time of clock clockid::realtime.

<a href="#lookupflags" name="lookupflags"></a> lookupflags: Flags(u32)

Flags determining the method of how paths are resolved.
Size: 4
Alignment: 4

Flags

• <a href="#lookupflags.symlink_follow" name="lookupflags.symlink_follow"></a> symlink_follow
  As long as the resolved path corresponds to a symbolic link, it is expanded.

<a href="#oflags" name="oflags"></a> oflags: Flags(u16)

Open flags used by path_open.
Size: 2
Alignment: 2

Flags

• <a href="#oflags.creat" name="oflags.creat"></a> creat
  Create file if it does not exist.

• <a href="#oflags.directory" name="oflags.directory"></a> directory
  Fail if not a directory.

• <a href="#oflags.excl" name="oflags.excl"></a> excl
  Fail if file already exists.

• <a href="#oflags.trunc" name="oflags.trunc"></a> trunc
  Truncate file to size 0.

<a href="#linkcount" name="linkcount"></a> linkcount: u64

Number of hard links to an inode.
Size: 8
Alignment: 8

<a href="#filestat" name="filestat"></a> filestat: Struct

File attributes.
Size: 64
Alignment: 8

Struct members

• <a href="#filestat.dev" name="filestat.dev"></a> dev: device
  Device ID of device containing the file.
  Offset: 0
• <a href="#filestat.ino" name="filestat.ino"></a> ino: inode
  File serial number.
  Offset: 8
• <a href="#filestat.filetype" name="filestat.filetype"></a> filetype: filetype
  File type.
  Offset: 16
• <a href="#filestat.nlink" name="filestat.nlink"></a> nlink: linkcount
  Number of hard links to the file.
  Offset: 24
• <a href="#filestat.size" name="filestat.size"></a> size: filesize
  For regular files, the file size in bytes. For symbolic links, the length in bytes of the pathname contained in the symbolic link.
  Offset: 32
• <a href="#filestat.atim" name="filestat.atim"></a> atim: timestamp
  Last data access timestamp.
  Offset: 40
• <a href="#filestat.mtim" name="filestat.mtim"></a> mtim: timestamp
  Last data modification timestamp.
  Offset: 48
• <a href="#filestat.ctim" name="filestat.ctim"></a> ctim: timestamp
  Last file status change timestamp.
  Offset: 56

  <a href="#userdata" name="userdata"></a> userdata: u64

  User-provided value that may be attached to objects that is retained when
  extracted from the implementation.
  Size: 8
  Alignment: 8

  <a href="#eventtype" name="eventtype"></a> eventtype: Enum(u8)

  Type of a subscription to an event or its occurrence.
  Size: 1
  Alignment: 1

  Variants

• <a href="#eventtype.clock" name="eventtype.clock"></a> clock
  The time value of clock subscription_clock::id has
  reached timestamp subscription_clock::timeout.

• <a href="#eventtype.fd_read" name="eventtype.fd_read"></a> fd_read
  File descriptor subscription_fd_readwrite::file_descriptor has data
  available for reading. This event always triggers for regular files.

• <a href="#eventtype.fd_write" name="eventtype.fd_write"></a> fd_write
  File descriptor subscription_fd_readwrite::file_descriptor has capacity
  available for writing. This event always triggers for regular files.

<a href="#eventrwflags" name="eventrwflags"></a> eventrwflags: Flags(u16)

The state of the file descriptor subscribed to with
eventtype::fd_read or eventtype::fd_write.
Size: 2
Alignment: 2

Flags

• <a href="#eventrwflags.fd_readwrite_hangup" name="eventrwflags.fd_readwrite_hangup"></a> fd_readwrite_hangup
  The peer of this socket has closed or disconnected.

<a href="#event_fd_readwrite" name="event_fd_readwrite"></a> event_fd_readwrite: Struct

The contents of an $event when type is eventtype::fd_read or
eventtype::fd_write.
Size: 16
Alignment: 8

Struct members

• <a href="#event_fd_readwrite.nbytes" name="event_fd_readwrite.nbytes"></a> nbytes: filesize
  The number of bytes available for reading or writing.
  Offset: 0
• <a href="#event_fd_readwrite.flags" name="event_fd_readwrite.flags"></a> flags: eventrwflags
  The state of the file descriptor.
  Offset: 8

  <a href="#event" name="event"></a> event: Struct

  An event that occurred.
  Size: 32
  Alignment: 8

  Struct members

• <a href="#event.userdata" name="event.userdata"></a> userdata: userdata
  User-provided value that got attached to subscription::userdata.
  Offset: 0
• <a href="#event.error" name="event.error"></a> error: errno
  If non-zero, an error that occurred while processing the subscription request.
  Offset: 8
• <a href="#event.type" name="event.type"></a> type: eventtype
  The type of event that occured
  Offset: 10
• <a href="#event.fd_readwrite" name="event.fd_readwrite"></a> fd_readwrite: event_fd_readwrite
  The contents of the event, if it is an eventtype::fd_read or
  eventtype::fd_write. eventtype::clock events ignore this field.
  Offset: 16

  <a href="#subclockflags" name="subclockflags"></a> subclockflags: Flags(u16)

  Flags determining how to interpret the timestamp provided in
  subscription_clock::timeout.
  Size: 2
  Alignment: 2

  Flags

• <a href="#subclockflags.subscription_clock_abstime" name="subclockflags.subscription_clock_abstime"></a> subscription_clock_abstime
  If set, treat the timestamp provided in
  subscription_clock::timeout as an absolute timestamp of clock
  subscription_clock::id. If clear, treat the timestamp
  provided in subscription_clock::timeout relative to the
  current time value of clock subscription_clock::id.

<a href="#subscription_clock" name="subscription_clock"></a> subscription_clock: Struct

The contents of a subscription when type is eventtype::clock.
Size: 32
Alignment: 8

Struct members

• <a href="#subscription_clock.id" name="subscription_clock.id"></a> id: clockid
  The clock against which to compare the timestamp.
  Offset: 0
• <a href="#subscription_clock.timeout" name="subscription_clock.timeout"></a> timeout: timestamp
  The absolute or relative timestamp.
  Offset: 8
• <a href="#subscription_clock.precision" name="subscription_clock.precision"></a> precision: timestamp
  The amount of time that the implementation may wait additionally
  to coalesce with other events.
  Offset: 16
• <a href="#subscription_clock.flags" name="subscription_clock.flags"></a> flags: subclockflags
  Flags specifying whether the timeout is absolute or relative
  Offset: 24

  <a href="#subscription_fd_readwrite" name="subscription_fd_readwrite"></a> subscription_fd_readwrite: Struct

  The contents of a subscription when type is type is
  eventtype::fd_read or eventtype::fd_write.
  Size: 4
  Alignment: 4

  Struct members

• <a href="#subscription_fd_readwrite.file_descriptor" name="subscription_fd_readwrite.file_descriptor"></a> file_descriptor: fd
  The file descriptor on which to wait for it to become ready for reading or writing.
  Offset: 0

  <a href="#subscription_u" name="subscription_u"></a> subscription_u: Union

  The contents of a subscription.
  Size: 40
  Alignment: 8

  Union Layout

• tag_size: 1
• tag_align: 1
• contents_offset: 8
• contents_size: 32
• contents_align: 8

  Union variants

• <a href="#subscription_u.clock" name="subscription_u.clock"></a> clock: subscription_clock

• <a href="#subscription_u.fd_read" name="subscription_u.fd_read"></a> fd_read: subscription_fd_readwrite

• <a href="#subscription_u.fd_write" name="subscription_u.fd_write"></a> fd_write: subscription_fd_readwrite

<a href="#subscription" name="subscription"></a> subscription: Struct

Subscription to an event.
Size: 48
Alignment: 8

Struct members

• <a href="#subscription.userdata" name="subscription.userdata"></a> userdata: userdata
  User-provided value that is attached to the subscription in the
  implementation and returned through event::userdata.
  Offset: 0
• <a href="#subscription.u" name="subscription.u"></a> u: subscription_u
  The type of the event to which to subscribe, and its contents
  Offset: 8

  <a href="#exitcode" name="exitcode"></a> exitcode: u32

  Exit code generated by a process when exiting.
  Size: 4
  Alignment: 4

  <a href="#signal" name="signal"></a> signal: Enum(u8)

  Signal condition.
  Size: 1
  Alignment: 1

  Variants

• <a href="#signal.none" name="signal.none"></a> none
  No signal. Note that POSIX has special semantics for kill(pid, 0),
  so this value is reserved.

• <a href="#signal.hup" name="signal.hup"></a> hup
  Hangup.
  Action: Terminates the process.

• <a href="#signal.int" name="signal.int"></a> int
  Terminate interrupt signal.
  Action: Terminates the process.

• <a href="#signal.quit" name="signal.quit"></a> quit
  Terminal quit signal.
  Action: Terminates the process.

• <a href="#signal.ill" name="signal.ill"></a> ill
  Illegal instruction.
  Action: Terminates the process.

• <a href="#signal.trap" name="signal.trap"></a> trap
  Trace/breakpoint trap.
  Action: Terminates the process.

• <a href="#signal.abrt" name="signal.abrt"></a> abrt
  Process abort signal.
  Action: Terminates the process.

• <a href="#signal.bus" name="signal.bus"></a> bus
  Access to an undefined portion of a memory object.
  Action: Terminates the process.

• <a href="#signal.fpe" name="signal.fpe"></a> fpe
  Erroneous arithmetic operation.
  Action: Terminates the process.

• <a href="#signal.kill" name="signal.kill"></a> kill
  Kill.
  Action: Terminates the process.

• <a href="#signal.usr1" name="signal.usr1"></a> usr1
  User-defined signal 1.
  Action: Terminates the process.

• <a href="#signal.segv" name="signal.segv"></a> segv
  Invalid memory reference.
  Action: Terminates the process.

• <a href="#signal.usr2" name="signal.usr2"></a> usr2
  User-defined signal 2.
  Action: Terminates the process.

• <a href="#signal.pipe" name="signal.pipe"></a> pipe
  Write on a pipe with no one to read it.
  Action: Ignored.

• <a href="#signal.alrm" name="signal.alrm"></a> alrm
  Alarm clock.
  Action: Terminates the process.

• <a href="#signal.term" name="signal.term"></a> term
  Termination signal.
  Action: Terminates the process.

• <a href="#signal.chld" name="signal.chld"></a> chld
  Child process terminated, stopped, or continued.
  Action: Ignored.

• <a href="#signal.cont" name="signal.cont"></a> cont
  Continue executing, if stopped.
  Action: Continues executing, if stopped.

• <a href="#signal.stop" name="signal.stop"></a> stop
  Stop executing.
  Action: Stops executing.

• <a href="#signal.tstp" name="signal.tstp"></a> tstp
  Terminal stop signal.
  Action: Stops executing.

• <a href="#signal.ttin" name="signal.ttin"></a> ttin
  Background process attempting read.
  Action: Stops executing.

• <a href="#signal.ttou" name="signal.ttou"></a> ttou
  Background process attempting write.
  Action: Stops executing.

• <a href="#signal.urg" name="signal.urg"></a> urg
  High bandwidth data is available at a socket.
  Action: Ignored.

• <a href="#signal.xcpu" name="signal.xcpu"></a> xcpu
  CPU time limit exceeded.
  Action: Terminates the process.

• <a href="#signal.xfsz" name="signal.xfsz"></a> xfsz
  File size limit exceeded.
  Action: Terminates the process.

• <a href="#signal.vtalrm" name="signal.vtalrm"></a> vtalrm
  Virtual timer expired.
  Action: Terminates the process.

• <a href="#signal.prof" name="signal.prof"></a> prof
  Profiling timer expired.
  Action: Terminates the process.

• <a href="#signal.winch" name="signal.winch"></a> winch
  Window changed.
  Action: Ignored.

• <a href="#signal.poll" name="signal.poll"></a> poll
  I/O possible.
  Action: Terminates the process.

• <a href="#signal.pwr" name="signal.pwr"></a> pwr
  Power failure.
  Action: Terminates the process.

• <a href="#signal.sys" name="signal.sys"></a> sys
  Bad system call.
  Action: Terminates the process.

<a href="#riflags" name="riflags"></a> riflags: Flags(u16)

Flags provided to sock_recv.
Size: 2
Alignment: 2

Flags

• <a href="#riflags.recv_peek" name="riflags.recv_peek"></a> recv_peek
  Returns the message without removing it from the socket's receive queue.

• <a href="#riflags.recv_waitall" name="riflags.recv_waitall"></a> recv_waitall
  On byte-stream sockets, block until the full amount of data can be returned.

<a href="#roflags" name="roflags"></a> roflags: Flags(u16)

Flags returned by sock_recv.
Size: 2
Alignment: 2

Flags

• <a href="#roflags.recv_data_truncated" name="roflags.recv_data_truncated"></a> recv_data_truncated
  Returned by sock_recv: Message data has been truncated.

<a href="#siflags" name="siflags"></a> siflags: u16

Flags provided to sock_send. As there are currently no flags
defined, it must be set to zero.
Size: 2
Alignment: 2

<a href="#sdflags" name="sdflags"></a> sdflags: Flags(u8)

Which channels on a socket to shut down.
Size: 1
Alignment: 1

Flags

• <a href="#sdflags.rd" name="sdflags.rd"></a> rd
  Disables further receive operations.

• <a href="#sdflags.wr" name="sdflags.wr"></a> wr
  Disables further send operations.

<a href="#preopentype" name="preopentype"></a> preopentype: Enum(u8)

Identifiers for preopened capabilities.
Size: 1
Alignment: 1

Variants

• <a href="#preopentype.dir" name="preopentype.dir"></a> dir
  A pre-opened directory.

<a href="#prestat_dir" name="prestat_dir"></a> prestat_dir: Struct

The contents of a $prestat when type is preopentype::dir.
Size: 4
Alignment: 4

Struct members

• <a href="#prestat_dir.pr_name_len" name="prestat_dir.pr_name_len"></a> pr_name_len: size
  The length of the directory name for use with fd_prestat_dir_name.
  Offset: 0

  <a href="#prestat" name="prestat"></a> prestat: Union

  Information about a pre-opened capability.
  Size: 8
  Alignment: 4

  Union Layout

• tag_size: 1
• tag_align: 1
• contents_offset: 4
• contents_size: 4
• contents_align: 4

  Union variants

• <a href="#prestat.dir" name="prestat.dir"></a> dir: prestat_dir

Modules

<a href="#wasi_snapshot_preview1" name="wasi_snapshot_preview1"></a> wasi_snapshot_preview1

Imports

Memory

Functions

<a href="#args_get" name="args_get"></a> args_get(argv: Pointer<Pointer<u8>>, argv_buf: Pointer<u8>) -> errno

Read command-line argument data.
The size of the array should match that returned by args_sizes_get

Params

• <a href="#args_get.argv" name="args_get.argv"></a> argv: Pointer<Pointer<u8>>

• <a href="#args_get.argv_buf" name="args_get.argv_buf"></a> argv_buf: Pointer<u8>

Results

• <a href="#args_get.error" name="args_get.error"></a> error: errno

<a href="#args_sizes_get" name="args_sizes_get"></a> args_sizes_get() -> (errno, size, size)

Return command-line argument data sizes.

Params

Results

• <a href="#args_sizes_get.error" name="args_sizes_get.error"></a> error: errno

• <a href="#args_sizes_get.argc" name="args_sizes_get.argc"></a> argc: size
  The number of arguments.

• <a href="#args_sizes_get.argv_buf_size" name="args_sizes_get.argv_buf_size"></a> argv_buf_size: size
  The size of the argument string data.

<a href="#environ_get" name="environ_get"></a> environ_get(environ: Pointer<Pointer<u8>>, environ_buf: Pointer<u8>) -> errno

Read environment variable data.
The sizes of the buffers should match that returned by environ_sizes_get.

Params

• <a href="#environ_get.environ" name="environ_get.environ"></a> environ: Pointer<Pointer<u8>>

• <a href="#environ_get.environ_buf" name="environ_get.environ_buf"></a> environ_buf: Pointer<u8>

Results

• <a href="#environ_get.error" name="environ_get.error"></a> error: errno

<a href="#environ_sizes_get" name="environ_sizes_get"></a> environ_sizes_get() -> (errno, size, size)

Return environment variable data sizes.

Params

Results

• <a href="#environ_sizes_get.error" name="environ_sizes_get.error"></a> error: errno

• <a href="#environ_sizes_get.environc" name="environ_sizes_get.environc"></a> environc: size
  The number of environment variable arguments.

• <a href="#environ_sizes_get.environ_buf_size" name="environ_sizes_get.environ_buf_size"></a> environ_buf_size: size
  The size of the environment variable data.

<a href="#clock_res_get" name="clock_res_get"></a> clock_res_get(id: clockid) -> (errno, timestamp)

Return the resolution of a clock.
Implementations are required to provide a non-zero value for supported clocks. For unsupported clocks,
return errno::inval.
Note: This is similar to clock_getres in POSIX.

Params

• <a href="#clock_res_get.id" name="clock_res_get.id"></a> id: clockid
  The clock for which to return the resolution.

Results

• <a href="#clock_res_get.error" name="clock_res_get.error"></a> error: errno

• <a href="#clock_res_get.resolution" name="clock_res_get.resolution"></a> resolution: timestamp
  The resolution of the clock.

<a href="#clock_time_get" name="clock_time_get"></a> clock_time_get(id: clockid, precision: timestamp) -> (errno, timestamp)

Return the time value of a clock.
Note: This is similar to clock_gettime in POSIX.

Params

• <a href="#clock_time_get.id" name="clock_time_get.id"></a> id: clockid
  The clock for which to return the time.

• <a href="#clock_time_get.precision" name="clock_time_get.precision"></a> precision: timestamp
  The maximum lag (exclusive) that the returned time value may have, compared to its actual value.

Results

• <a href="#clock_time_get.error" name="clock_time_get.error"></a> error: errno

• <a href="#clock_time_get.time" name="clock_time_get.time"></a> time: timestamp
  The time value of the clock.

<a href="#fd_advise" name="fd_advise"></a> fd_advise(fd: fd, offset: filesize, len: filesize, advice: advice) -> errno

Provide file advisory information on a file descriptor.
Note: This is similar to posix_fadvise in POSIX.

Params

• <a href="#fd_advise.fd" name="fd_advise.fd"></a> fd: fd

• <a href="#fd_advise.offset" name="fd_advise.offset"></a> offset: filesize
  The offset within the file to which the advisory applies.

• <a href="#fd_advise.len" name="fd_advise.len"></a> len: filesize
  The length of the region to which the advisory applies.

• <a href="#fd_advise.advice" name="fd_advise.advice"></a> advice: advice
  The advice.

Results

• <a href="#fd_advise.error" name="fd_advise.error"></a> error: errno

<a href="#fd_allocate" name="fd_allocate"></a> fd_allocate(fd: fd, offset: filesize, len: filesize) -> errno

Force the allocation of space in a file.
Note: This is similar to posix_fallocate in POSIX.

Params

• <a href="#fd_allocate.fd" name="fd_allocate.fd"></a> fd: fd

• <a href="#fd_allocate.offset" name="fd_allocate.offset"></a> offset: filesize
  The offset at which to start the allocation.

• <a href="#fd_allocate.len" name="fd_allocate.len"></a> len: filesize
  The length of the area that is allocated.

Results

• <a href="#fd_allocate.error" name="fd_allocate.error"></a> error: errno

<a href="#fd_close" name="fd_close"></a> fd_close(fd: fd) -> errno

Close a file descriptor.
Note: This is similar to close in POSIX.

Params

• <a href="#fd_close.fd" name="fd_close.fd"></a> fd: fd

Results

• <a href="#fd_close.error" name="fd_close.error"></a> error: errno

<a href="#fd_datasync" name="fd_datasync"></a> fd_datasync(fd: fd) -> errno

Synchronize the data of a file to disk.
Note: This is similar to fdatasync in POSIX.

Params

• <a href="#fd_datasync.fd" name="fd_datasync.fd"></a> fd: fd

Results

• <a href="#fd_datasync.error" name="fd_datasync.error"></a> error: errno

<a href="#fd_fdstat_get" name="fd_fdstat_get"></a> fd_fdstat_get(fd: fd) -> (errno, fdstat)

Get the attributes of a file descriptor.
Note: This returns similar flags to fsync(fd, F_GETFL) in POSIX, as well as additional fields.

Params

• <a href="#fd_fdstat_get.fd" name="fd_fdstat_get.fd"></a> fd: fd

Results

• <a href="#fd_fdstat_get.error" name="fd_fdstat_get.error"></a> error: errno

• <a href="#fd_fdstat_get.stat" name="fd_fdstat_get.stat"></a> stat: fdstat
  The buffer where the file descriptor's attributes are stored.

<a href="#fd_fdstat_set_flags" name="fd_fdstat_set_flags"></a> fd_fdstat_set_flags(fd: fd, flags: fdflags) -> errno

Adjust the flags associated with a file descriptor.
Note: This is similar to fcntl(fd, F_SETFL, flags) in POSIX.

Params

• <a href="#fd_fdstat_set_flags.fd" name="fd_fdstat_set_flags.fd"></a> fd: fd

• <a href="#fd_fdstat_set_flags.flags" name="fd_fdstat_set_flags.flags"></a> flags: fdflags
  The desired values of the file descriptor flags.

Results

• <a href="#fd_fdstat_set_flags.error" name="fd_fdstat_set_flags.error"></a> error: errno

<a href="#fd_fdstat_set_rights" name="fd_fdstat_set_rights"></a> fd_fdstat_set_rights(fd: fd, fs_rights_base: rights, fs_rights_inheriting: rights) -> errno

Adjust the rights associated with a file descriptor.
This can only be used to remove rights, and returns errno::notcapable if called in a way that would attempt to add rights

Params

• <a href="#fd_fdstat_set_rights.fd" name="fd_fdstat_set_rights.fd"></a> fd: fd

• <a href="#fd_fdstat_set_rights.fs_rights_base" name="fd_fdstat_set_rights.fs_rights_base"></a> fs_rights_base: rights
  The desired rights of the file descriptor.

• <a href="#fd_fdstat_set_rights.fs_rights_inheriting" name="fd_fdstat_set_rights.fs_rights_inheriting"></a> fs_rights_inheriting: rights

Results

• <a href="#fd_fdstat_set_rights.error" name="fd_fdstat_set_rights.error"></a> error: errno

<a href="#fd_filestat_get" name="fd_filestat_get"></a> fd_filestat_get(fd: fd) -> (errno, filestat)

Return the attributes of an open file.

Params

• <a href="#fd_filestat_get.fd" name="fd_filestat_get.fd"></a> fd: fd

Results

• <a href="#fd_filestat_get.error" name="fd_filestat_get.error"></a> error: errno

• <a href="#fd_filestat_get.buf" name="fd_filestat_get.buf"></a> buf: filestat
  The buffer where the file's attributes are stored.

<a href="#fd_filestat_set_size" name="fd_filestat_set_size"></a> fd_filestat_set_size(fd: fd, size: filesize) -> errno

Adjust the size of an open file. If this increases the file's size, the extra bytes are filled with zeros.
Note: This is similar to ftruncate in POSIX.

Params

• <a href="#fd_filestat_set_size.fd" name="fd_filestat_set_size.fd"></a> fd: fd

• <a href="#fd_filestat_set_size.size" name="fd_filestat_set_size.size"></a> size: filesize
  The desired file size.

Results

• <a href="#fd_filestat_set_size.error" name="fd_filestat_set_size.error"></a> error: errno

<a href="#fd_filestat_set_times" name="fd_filestat_set_times"></a> fd_filestat_set_times(fd: fd, atim: timestamp, mtim: timestamp, fst_flags: fstflags) -> errno

Adjust the timestamps of an open file or directory.
Note: This is similar to futimens in POSIX.

Params

• <a href="#fd_filestat_set_times.fd" name="fd_filestat_set_times.fd"></a> fd: fd

• <a href="#fd_filestat_set_times.atim" name="fd_filestat_set_times.atim"></a> atim: timestamp
  The desired values of the data access timestamp.

• <a href="#fd_filestat_set_times.mtim" name="fd_filestat_set_times.mtim"></a> mtim: timestamp
  The desired values of the data modification timestamp.

• <a href="#fd_filestat_set_times.fst_flags" name="fd_filestat_set_times.fst_flags"></a> fst_flags: fstflags
  A bitmask indicating which timestamps to adjust.

Results

• <a href="#fd_filestat_set_times.error" name="fd_filestat_set_times.error"></a> error: errno

<a href="#fd_pread" name="fd_pread"></a> fd_pread(fd: fd, iovs: iovec_array, offset: filesize) -> (errno, size)

Read from a file descriptor, without using and updating the file descriptor's offset.
Note: This is similar to preadv in POSIX.

Params

• <a href="#fd_pread.fd" name="fd_pread.fd"></a> fd: fd

• <a href="#fd_pread.iovs" name="fd_pread.iovs"></a> iovs: iovec_array
  List of scatter/gather vectors in which to store data.

• <a href="#fd_pread.offset" name="fd_pread.offset"></a> offset: filesize
  The offset within the file at which to read.

Results

• <a href="#fd_pread.error" name="fd_pread.error"></a> error: errno

• <a href="#fd_pread.nread" name="fd_pread.nread"></a> nread: size
  The number of bytes read.

<a href="#fd_prestat_get" name="fd_prestat_get"></a> fd_prestat_get(fd: fd) -> (errno, prestat)

Return a description of the given preopened file descriptor.

Params

• <a href="#fd_prestat_get.fd" name="fd_prestat_get.fd"></a> fd: fd

Results

• <a href="#fd_prestat_get.error" name="fd_prestat_get.error"></a> error: errno

• <a href="#fd_prestat_get.buf" name="fd_prestat_get.buf"></a> buf: prestat
  The buffer where the description is stored.

<a href="#fd_prestat_dir_name" name="fd_prestat_dir_name"></a> fd_prestat_dir_name(fd: fd, path: Pointer<u8>, path_len: size) -> errno

Return a description of the given preopened file descriptor.

Params

• <a href="#fd_prestat_dir_name.fd" name="fd_prestat_dir_name.fd"></a> fd: fd

• <a href="#fd_prestat_dir_name.path" name="fd_prestat_dir_name.path"></a> path: Pointer<u8>
  A buffer into which to write the preopened directory name.

• <a href="#fd_prestat_dir_name.path_len" name="fd_prestat_dir_name.path_len"></a> path_len: size

Results

• <a href="#fd_prestat_dir_name.error" name="fd_prestat_dir_name.error"></a> error: errno

<a href="#fd_pwrite" name="fd_pwrite"></a> fd_pwrite(fd: fd, iovs: ciovec_array, offset: filesize) -> (errno, size)

Write to a file descriptor, without using and updating the file descriptor's offset.
Note: This is similar to pwritev in POSIX.

Params

• <a href="#fd_pwrite.fd" name="fd_pwrite.fd"></a> fd: fd

• <a href="#fd_pwrite.iovs" name="fd_pwrite.iovs"></a> iovs: ciovec_array
  List of scatter/gather vectors from which to retrieve data.

• <a href="#fd_pwrite.offset" name="fd_pwrite.offset"></a> offset: filesize
  The offset within the file at which to write.

Results

• <a href="#fd_pwrite.error" name="fd_pwrite.error"></a> error: errno

• <a href="#fd_pwrite.nwritten" name="fd_pwrite.nwritten"></a> nwritten: size
  The number of bytes written.

<a href="#fd_read" name="fd_read"></a> fd_read(fd: fd, iovs: iovec_array) -> (errno, size)

Read from a file descriptor.
Note: This is similar to readv in POSIX.

Params

• <a href="#fd_read.fd" name="fd_read.fd"></a> fd: fd

• <a href="#fd_read.iovs" name="fd_read.iovs"></a> iovs: iovec_array
  List of scatter/gather vectors to which to store data.

Results

• <a href="#fd_read.error" name="fd_read.error"></a> error: errno

• <a href="#fd_read.nread" name="fd_read.nread"></a> nread: size
  The number of bytes read.

<a href="#fd_readdir" name="fd_readdir"></a> fd_readdir(fd: fd, buf: Pointer<u8>, buf_len: size, cookie: dircookie) -> (errno, size)

Read directory entries from a directory.
When successful, the contents of the output buffer consist of a sequence of
directory entries. Each directory entry consists of a dirent_t object,
followed by dirent_t::d_namlen bytes holding the name of the directory
entry.
This function fills the output buffer as much as possible, potentially
truncating the last directory entry. This allows the caller to grow its
read buffer size in case it's too small to fit a single large directory
entry, or skip the oversized directory entry.

Params

• <a href="#fd_readdir.fd" name="fd_readdir.fd"></a> fd: fd

• <a href="#fd_readdir.buf" name="fd_readdir.buf"></a> buf: Pointer<u8>
  The buffer where directory entries are stored

• <a href="#fd_readdir.buf_len" name="fd_readdir.buf_len"></a> buf_len: size

• <a href="#fd_readdir.cookie" name="fd_readdir.cookie"></a> cookie: dircookie
  The location within the directory to start reading

Results

• <a href="#fd_readdir.error" name="fd_readdir.error"></a> error: errno

• <a href="#fd_readdir.bufused" name="fd_readdir.bufused"></a> bufused: size
  The number of bytes stored in the read buffer. If less than the size of the read buffer, the end of the directory has been reached.

<a href="#fd_renumber" name="fd_renumber"></a> fd_renumber(fd: fd, to: fd) -> errno

Atomically replace a file descriptor by renumbering another file descriptor.
Due to the strong focus on thread safety, this environment does not provide
a mechanism to duplicate or renumber a file descriptor to an arbitrary
number, like dup2(). This would be prone to race conditions, as an actual
file descriptor with the same number could be allocated by a different
thread at the same time.
This function provides a way to atomically renumber file descriptors, which
would disappear if dup2() were to be removed entirely.

Params

• <a href="#fd_renumber.fd" name="fd_renumber.fd"></a> fd: fd

• <a href="#fd_renumber.to" name="fd_renumber.to"></a> to: fd
  The file descriptor to overwrite.

Results

• <a href="#fd_renumber.error" name="fd_renumber.error"></a> error: errno

<a href="#fd_seek" name="fd_seek"></a> fd_seek(fd: fd, offset: filedelta, whence: whence) -> (errno, filesize)

Move the offset of a file descriptor.
Note: This is similar to lseek in POSIX.

Params

• <a href="#fd_seek.fd" name="fd_seek.fd"></a> fd: fd

• <a href="#fd_seek.offset" name="fd_seek.offset"></a> offset: filedelta
  The number of bytes to move.

• <a href="#fd_seek.whence" name="fd_seek.whence"></a> whence: whence
  The base from which the offset is relative.

Results

• <a href="#fd_seek.error" name="fd_seek.error"></a> error: errno

• <a href="#fd_seek.newoffset" name="fd_seek.newoffset"></a> newoffset: filesize
  The new offset of the file descriptor, relative to the start of the file.

<a href="#fd_sync" name="fd_sync"></a> fd_sync(fd: fd) -> errno

Synchronize the data and metadata of a file to disk.
Note: This is similar to fsync in POSIX.

Params

• <a href="#fd_sync.fd" name="fd_sync.fd"></a> fd: fd

Results

• <a href="#fd_sync.error" name="fd_sync.error"></a> error: errno

<a href="#fd_tell" name="fd_tell"></a> fd_tell(fd: fd) -> (errno, filesize)

Return the current offset of a file descriptor.
Note: This is similar to lseek(fd, 0, SEEK_CUR) in POSIX.

Params

• <a href="#fd_tell.fd" name="fd_tell.fd"></a> fd: fd

Results

• <a href="#fd_tell.error" name="fd_tell.error"></a> error: errno

• <a href="#fd_tell.offset" name="fd_tell.offset"></a> offset: filesize
  The current offset of the file descriptor, relative to the start of the file.

<a href="#fd_write" name="fd_write"></a> fd_write(fd: fd, iovs: ciovec_array) -> (errno, size)

Write to a file descriptor.
Note: This is similar to writev in POSIX.

Params

• <a href="#fd_write.fd" name="fd_write.fd"></a> fd: fd

• <a href="#fd_write.iovs" name="fd_write.iovs"></a> iovs: ciovec_array
  List of scatter/gather vectors from which to retrieve data.

Results

• <a href="#fd_write.error" name="fd_write.error"></a> error: errno

• <a href="#fd_write.nwritten" name="fd_write.nwritten"></a> nwritten: size
  The number of bytes written.

<a href="#path_create_directory" name="path_create_directory"></a> path_create_directory(fd: fd, path: string) -> errno

Create a directory.
Note: This is similar to mkdirat in POSIX.

Params

• <a href="#path_create_directory.fd" name="path_create_directory.fd"></a> fd: fd

• <a href="#path_create_directory.path" name="path_create_directory.path"></a> path: string
  The path at which to create the directory.

Results

• <a href="#path_create_directory.error" name="path_create_directory.error"></a> error: errno

<a href="#path_filestat_get" name="path_filestat_get"></a> path_filestat_get(fd: fd, flags: lookupflags, path: string) -> (errno, filestat)

Return the attributes of a file or directory.
Note: This is similar to stat in POSIX.

Params

• <a href="#path_filestat_get.fd" name="path_filestat_get.fd"></a> fd: fd

• <a href="#path_filestat_get.flags" name="path_filestat_get.flags"></a> flags: lookupflags
  Flags determining the method of how the path is resolved.

• <a href="#path_filestat_get.path" name="path_filestat_get.path"></a> path: string
  The path of the file or directory to inspect.

Results

• <a href="#path_filestat_get.error" name="path_filestat_get.error"></a> error: errno

• <a href="#path_filestat_get.buf" name="path_filestat_get.buf"></a> buf: filestat
  The buffer where the file's attributes are stored.

<a href="#path_filestat_set_times" name="path_filestat_set_times"></a> path_filestat_set_times(fd: fd, flags: lookupflags, path: string, atim: timestamp, mtim: timestamp, fst_flags: fstflags) -> errno

Adjust the timestamps of a file or directory.
Note: This is similar to utimensat in POSIX.

Params

• <a href="#path_filestat_set_times.fd" name="path_filestat_set_times.fd"></a> fd: fd

• <a href="#path_filestat_set_times.flags" name="path_filestat_set_times.flags"></a> flags: lookupflags
  Flags determining the method of how the path is resolved.

• <a href="#path_filestat_set_times.path" name="path_filestat_set_times.path"></a> path: string
  The path of the file or directory to operate on.

• <a href="#path_filestat_set_times.atim" name="path_filestat_set_times.atim"></a> atim: timestamp
  The desired values of the data access timestamp.

• <a href="#path_filestat_set_times.mtim" name="path_filestat_set_times.mtim"></a> mtim: timestamp
  The desired values of the data modification timestamp.

• <a href="#path_filestat_set_times.fst_flags" name="path_filestat_set_times.fst_flags"></a> fst_flags: fstflags
  A bitmask indicating which timestamps to adjust.

Results

• <a href="#path_filestat_set_times.error" name="path_filestat_set_times.error"></a> error: errno

<a href="#path_link" name="path_link"></a> path_link(old_fd: fd, old_flags: lookupflags, old_path: string, new_fd: fd, new_path: string) -> errno

Create a hard link.
Note: This is similar to linkat in POSIX.

Params

• <a href="#path_link.old_fd" name="path_link.old_fd"></a> old_fd: fd

• <a href="#path_link.old_flags" name="path_link.old_flags"></a> old_flags: lookupflags
  Flags determining the method of how the path is resolved.

• <a href="#path_link.old_path" name="path_link.old_path"></a> old_path: string
  The source path from which to link.

• <a href="#path_link.new_fd" name="path_link.new_fd"></a> new_fd: fd
  The working directory at which the resolution of the new path starts.

• <a href="#path_link.new_path" name="path_link.new_path"></a> new_path: string
  The destination path at which to create the hard link.

Results

• <a href="#path_link.error" name="path_link.error"></a> error: errno

<a href="#path_open" name="path_open"></a> path_open(fd: fd, dirflags: lookupflags, path: string, oflags: oflags, fs_rights_base: rights, fs_rights_inherting: rights, fdflags: fdflags) -> (errno, fd)

Open a file or directory.
The returned file descriptor is not guaranteed to be the lowest-numbered
file descriptor not currently open; it is randomized to prevent
applications from depending on making assumptions about indexes, since this
is error-prone in multi-threaded contexts. The returned file descriptor is
guaranteed to be less than 2**31.
Note: This is similar to openat in POSIX.

Params

• <a href="#path_open.fd" name="path_open.fd"></a> fd: fd

• <a href="#path_open.dirflags" name="path_open.dirflags"></a> dirflags: lookupflags
  Flags determining the method of how the path is resolved.

• <a href="#path_open.path" name="path_open.path"></a> path: string
  The relative path of the file or directory to open, relative to the
  path_open::fd directory.

• <a href="#path_open.oflags" name="path_open.oflags"></a> oflags: oflags
  The method by which to open the file.

• <a href="#path_open.fs_rights_base" name="path_open.fs_rights_base"></a> fs_rights_base: rights
  The initial rights of the newly created file descriptor. The
  implementation is allowed to return a file descriptor with fewer rights
  than specified, if and only if those rights do not apply to the type of
  file being opened.
  The base rights are rights that will apply to operations using the file
  descriptor itself, while the inheriting rights are rights that apply to
  file descriptors derived from it.

• <a href="#path_open.fs_rights_inherting" name="path_open.fs_rights_inherting"></a> fs_rights_inherting: rights

• <a href="#path_open.fdflags" name="path_open.fdflags"></a> fdflags: fdflags

Results

• <a href="#path_open.error" name="path_open.error"></a> error: errno

• <a href="#path_open.opened_fd" name="path_open.opened_fd"></a> opened_fd: fd
  The file descriptor of the file that has been opened.

<a href="#path_readlink" name="path_readlink"></a> path_readlink(fd: fd, path: string, buf: Pointer<u8>, buf_len: size) -> (errno, size)

Read the contents of a symbolic link.
Note: This is similar to readlinkat in POSIX.

Params

• <a href="#path_readlink.fd" name="path_readlink.fd"></a> fd: fd

• <a href="#path_readlink.path" name="path_readlink.path"></a> path: string
  The path of the symbolic link from which to read.

• <a href="#path_readlink.buf" name="path_readlink.buf"></a> buf: Pointer<u8>
  The buffer to which to write the contents of the symbolic link.

• <a href="#path_readlink.buf_len" name="path_readlink.buf_len"></a> buf_len: size

Results

• <a href="#path_readlink.error" name="path_readlink.error"></a> error: errno

• <a href="#path_readlink.bufused" name="path_readlink.bufused"></a> bufused: size
  The number of bytes placed in the buffer.

<a href="#path_remove_directory" name="path_remove_directory"></a> path_remove_directory(fd: fd, path: string) -> errno

Remove a directory.
Return errno::notempty if the directory is not empty.
Note: This is similar to unlinkat(fd, path, AT_REMOVEDIR) in POSIX.

Params

• <a href="#path_remove_directory.fd" name="path_remove_directory.fd"></a> fd: fd

• <a href="#path_remove_directory.path" name="path_remove_directory.path"></a> path: string
  The path to a directory to remove.

Results

• <a href="#path_remove_directory.error" name="path_remove_directory.error"></a> error: errno

<a href="#path_rename" name="path_rename"></a> path_rename(fd: fd, old_path: string, new_fd: fd, new_path: string) -> errno

Rename a file or directory.
Note: This is similar to renameat in POSIX.

Params

• <a href="#path_rename.fd" name="path_rename.fd"></a> fd: fd

• <a href="#path_rename.old_path" name="path_rename.old_path"></a> old_path: string
  The source path of the file or directory to rename.

• <a href="#path_rename.new_fd" name="path_rename.new_fd"></a> new_fd: fd
  The working directory at which the resolution of the new path starts.

• <a href="#path_rename.new_path" name="path_rename.new_path"></a> new_path: string
  The destination path to which to rename the file or directory.

Results

• <a href="#path_rename.error" name="path_rename.error"></a> error: errno

<a href="#path_symlink" name="path_symlink"></a> path_symlink(old_path: string, fd: fd, new_path: string) -> errno

Create a symbolic link.
Note: This is similar to symlinkat in POSIX.

Params

• <a href="#path_symlink.old_path" name="path_symlink.old_path"></a> old_path: string
  The contents of the symbolic link.

• <a href="#path_symlink.fd" name="path_symlink.fd"></a> fd: fd

• <a href="#path_symlink.new_path" name="path_symlink.new_path"></a> new_path: string
  The destination path at which to create the symbolic link.

Results

• <a href="#path_symlink.error" name="path_symlink.error"></a> error: errno

<a href="#path_unlink_file" name="path_unlink_file"></a> path_unlink_file(fd: fd, path: string) -> errno

Unlink a file.
Return errno::isdir if the path refers to a directory.
Note: This is similar to unlinkat(fd, path, 0) in POSIX.

Params

• <a href="#path_unlink_file.fd" name="path_unlink_file.fd"></a> fd: fd

• <a href="#path_unlink_file.path" name="path_unlink_file.path"></a> path: string
  The path to a file to unlink.

Results

• <a href="#path_unlink_file.error" name="path_unlink_file.error"></a> error: errno

<a href="#poll_oneoff" name="poll_oneoff"></a> poll_oneoff(in: ConstPointer<subscription>, out: Pointer<event>, nsubscriptions: size) -> (errno, size)

Concurrently poll for the occurrence of a set of events.

Params

• <a href="#poll_oneoff.in" name="poll_oneoff.in"></a> in: ConstPointer<subscription>
  The events to which to subscribe.

• <a href="#poll_oneoff.out" name="poll_oneoff.out"></a> out: Pointer<event>
  The events that have occurred.

• <a href="#poll_oneoff.nsubscriptions" name="poll_oneoff.nsubscriptions"></a> nsubscriptions: size
  Both the number of subscriptions and events.

Results

• <a href="#poll_oneoff.error" name="poll_oneoff.error"></a> error: errno

• <a href="#poll_oneoff.nevents" name="poll_oneoff.nevents"></a> nevents: size
  The number of events stored.

<a href="#proc_exit" name="proc_exit"></a> proc_exit(rval: exitcode)

Terminate the process normally. An exit code of 0 indicates successful
termination of the program. The meanings of other values is dependent on
the environment.

Params

• <a href="#proc_exit.rval" name="proc_exit.rval"></a> rval: exitcode
  The exit code returned by the process.

Results

<a href="#proc_raise" name="proc_raise"></a> proc_raise(sig: signal) -> errno

Send a signal to the process of the calling thread.
Note: This is similar to raise in POSIX.

Params

• <a href="#proc_raise.sig" name="proc_raise.sig"></a> sig: signal
  The signal condition to trigger.

Results

• <a href="#proc_raise.error" name="proc_raise.error"></a> error: errno

<a href="#sched_yield" name="sched_yield"></a> sched_yield() -> errno

Temporarily yield execution of the calling thread.
Note: This is similar to sched_yield in POSIX.

Params

Results

• <a href="#sched_yield.error" name="sched_yield.error"></a> error: errno

<a href="#random_get" name="random_get"></a> random_get(buf: Pointer<u8>, buf_len: size) -> errno

Write high-quality random data into a buffer.
This function blocks when the implementation is unable to immediately
provide sufficient high-quality random data.
This function may execute slowly, so when large mounts of random data are
required, it's advisable to use this function to seed a pseudo-random
number generator, rather than to provide the random data directly.

Params

• <a href="#random_get.buf" name="random_get.buf"></a> buf: Pointer<u8>
  The buffer to fill with random data.

• <a href="#random_get.buf_len" name="random_get.buf_len"></a> buf_len: size

Results

• <a href="#random_get.error" name="random_get.error"></a> error: errno

<a href="#sock_recv" name="sock_recv"></a> sock_recv(fd: fd, ri_data: iovec_array, ri_flags: riflags) -> (errno, size, roflags)

Receive a message from a socket.
Note: This is similar to recv in POSIX, though it also supports reading
the data into multiple buffers in the manner of readv.

Params

• <a href="#sock_recv.fd" name="sock_recv.fd"></a> fd: fd

• <a href="#sock_recv.ri_data" name="sock_recv.ri_data"></a> ri_data: iovec_array
  List of scatter/gather vectors to which to store data.

• <a href="#sock_recv.ri_flags" name="sock_recv.ri_flags"></a> ri_flags: riflags
  Message flags.

Results

• <a href="#sock_recv.error" name="sock_recv.error"></a> error: errno

• <a href="#sock_recv.ro_datalen" name="sock_recv.ro_datalen"></a> ro_datalen: size
  Number of bytes stored in ri_data.

• <a href="#sock_recv.ro_flags" name="sock_recv.ro_flags"></a> ro_flags: roflags
  Message flags.

<a href="#sock_send" name="sock_send"></a> sock_send(fd: fd, si_data: ciovec_array, si_flags: siflags) -> (errno, size)

Send a message on a socket.
Note: This is similar to send in POSIX, though it also supports writing
the data from multiple buffers in the manner of writev.

Params

• <a href="#sock_send.fd" name="sock_send.fd"></a> fd: fd

• <a href="#sock_send.si_data" name="sock_send.si_data"></a> si_data: ciovec_array
  List of scatter/gather vectors to which to retrieve data

• <a href="#sock_send.si_flags" name="sock_send.si_flags"></a> si_flags: siflags
  Message flags.

Results

• <a href="#sock_send.error" name="sock_send.error"></a> error: errno

• <a href="#sock_send.so_datalen" name="sock_send.so_datalen"></a> so_datalen: size
  Number of bytes transmitted.

<a href="#sock_shutdown" name="sock_shutdown"></a> sock_shutdown(fd: fd, how: sdflags) -> errno

Shut down socket send and receive channels.
Note: This is similar to shutdown in POSIX.

Params

• <a href="#sock_shutdown.fd" name="sock_shutdown.fd"></a> fd: fd

• <a href="#sock_shutdown.how" name="sock_shutdown.how"></a> how: sdflags
  Which channels on the socket to shut down.

Results

• <a href="#sock_shutdown.error" name="sock_shutdown.error"></a> error: errno