namespace Deno

The global namespace where Deno specific, non-standard APIs are located.

Namespaces

A set of error constructors that are raised by Deno APIs.

Classes

c
Deno.Buffer
deprecated

A variable-sized buffer of bytes with read() and write() methods.

c
Deno.Child
deprecated

Create a child process.

Raised when attempting to open a server listener on an address and port that already has a listener.

Raised when the underlying operating system reports an EADDRNOTAVAIL error.

Raised when trying to create a resource, like a file, that already exits.

The underlying IO resource is invalid or closed, and so the operation could not be performed.

Raised when trying to write to a resource and a broken pipe error occurs. This can happen when trying to write directly to stdout or stderr and the operating system is unable to pipe the output for a reason external to the Deno runtime.

Raised when the underlying IO resource is not available because it is being awaited on in another block of code.

Raised when the underlying operating system reports an ECONNABORTED error.

Raised when the underlying operating system reports that a connection to a resource is refused.

Raised when the underlying operating system reports that a connection has been reset. With network servers, it can be a normal occurrence where a client will abort a connection instead of properly shutting it down.

Raised in situations where when attempting to load a dynamic import, too many redirects were encountered.

Raised when the underlying operating system reports an EINTR error. In many cases, this underlying IO error will be handled internally within Deno, or result in an @{link BadResource} error instead.

Raised when an operation to returns data that is invalid for the operation being performed.

Raised when the underlying operating system reports an ENOTCONN error.

Raised when the underlying operating system indicates that the file was not found.

Raised when the underlying Deno API is asked to perform a function that is not currently supported.

Raised when the underlying operating system indicates the current user which the Deno process is running under does not have the appropriate permissions to a file or resource, or the user did not provide required --allow-* flag.

Raised when the underlying operating system reports that an I/O operation has timed out (ETIMEDOUT).

Raised when attempting to read bytes from a resource, but the EOF was unexpectedly encountered.

Raised when expecting to write to a IO buffer resulted in zero bytes being written.

The Deno abstraction for reading and writing files.

Deno's permission management API.

An EventTarget returned from the Deno.permissions API which can provide updates to any state changes of the permission.

Represents an instance of a sub process that is returned from Deno.run which can be used to manage the sub-process.

An unsafe function pointer for passing JavaScript functions as C function pointers to foreign function calls.

An unsafe pointer to a function, for calling functions that are not present as symbols.

An unsafe pointer to a memory location for passing and returning pointers to and from the FFI.

An unsafe pointer view to a memory location as specified by the pointer value. The UnsafePointerView API follows the standard built in interface {@link DataView} for accessing the underlying types at an memory location (numbers, strings and raw bytes).

Enums

A enum which defines the seek mode for IO related APIs that support seeking.

Variables

Returns the script arguments to the program.

Information related to the build of the current Deno runtime.

A symbol which can be used as a key for a custom method which will be called when Deno.inspect() is called, or when the object is logged to the console.

An interface containing methods to interact with the process environment variables.

v
Deno.File
deprecated

The Deno abstraction for reading and writing files.

The URL of the entrypoint module entered from the command-line. It requires read permission to the CWD.

Reflects the NO_COLOR environment variable at program start.

Deno's permission management API.

The current process ID of this instance of the Deno CLI.

The process ID of parent process of this instance of the Deno CLI.

A reference to stderr which can be used to write directly to stderr. It implements the Deno specific Writer, WriterSync, and Closer interfaces as well as provides a WritableStream interface.

A reference to stdin which can be used to read directly from stdin. It implements the Deno specific Reader, ReaderSync, and Closer interfaces as well as provides a ReadableStream interface.

A reference to stdout which can be used to write directly to stdout. It implements the Deno specific Writer, WriterSync, and Closer interfaces as well as provides a WritableStream interface.

Version information related to the current Deno CLI runtime environment.

Functions

Registers the given function as a listener of the given signal event.

Register a benchmark test which will be run when deno bench is used on the command line and the containing module looks like a bench module.

Change the current working directory to the specified path.

Changes the permission of a specific file/directory of specified path. Ignores the process's umask.

Synchronously changes the permission of a specific file/directory of specified path. Ignores the process's umask.

Change owner of a regular file or directory.

Synchronously change owner of a regular file or directory.

Close the given resource ID (rid) which has been previously opened, such as via opening or creating a file. Closing a file when you are finished with it is important to avoid leaking resources.

Connects to the hostname (default is "127.0.0.1") and port on the named transport (default is "tcp"), and resolves to the connection (Conn).

Establishes a secure connection over TLS (transport layer security) using an optional cert file, hostname (default is "127.0.0.1") and port. The cert file is optional and if not included Mozilla's root certificates will be used (see also https://github.com/ctz/webpki-roots for specifics)

Gets the size of the console as columns/rows.

f
Deno.copy
deprecated

Copies from src to dst until either EOF (null) is read from src or an error occurs. It resolves to the number of bytes copied or rejects with the first error encountered while copying.

Copies the contents and permissions of one file to another specified path, by default creating a new file if needed, else overwriting. Fails if target path is a directory or is unwritable.

Synchronously copies the contents and permissions of one file to another specified path, by default creating a new file if needed, else overwriting. Fails if target path is a directory or is unwritable.

Creates a file if none exists or truncates an existing file and resolves to an instance of Deno.FsFile.

Create a custom HttpClient for to use with fetch. This is an extension of the web platform Fetch API which allows Deno to use custom TLS certificates and connect via a proxy while using fetch().

Creates a file if none exists or truncates an existing file and returns an instance of Deno.FsFile.

Return a string representing the current working directory.

Opens an external dynamic library and registers symbols, making foreign functions available to be called.

Returns the path to the current deno executable.

Exit the Deno process with optional exit code.

Flushes any pending data operations of the given file stream to disk.

Synchronously flushes any pending data operations of the given file stream to disk.

Acquire an advisory file-system lock for the provided file. exclusive defaults to false.

Acquire an advisory file-system lock synchronously for the provided file. exclusive defaults to false.

Returns a Deno.FileInfo for the given file stream.

Synchronously returns a Deno.FileInfo for the given file stream.

Flushes any pending data and metadata operations of the given file stream to disk.

Synchronously flushes any pending data and metadata operations of the given file stream to disk.

Truncates or extends the specified file stream, to reach the specified len.

Synchronously truncates or extends the specified file stream, to reach the specified len.

Release an advisory file-system lock for the provided file.

Release an advisory file-system lock for the provided file synchronously.

Changes the access (atime) and modification (mtime) times of a file stream resource referenced by rid. Given times are either in seconds (UNIX epoch time) or as Date objects.

Synchronously changes the access (atime) and modification (mtime) times of a file stream resource referenced by rid. Given times are either in seconds (UNIX epoch time) or as Date objects.

Returns the group id of the process on POSIX platforms. Returns null on windows.

Get the hostname of the machine the Deno process is running on.

Converts the input into a string that has the same format as printed by console.log().

Check if a given resource id (rid) is a TTY (a terminal).

f
Deno.iter
deprecated

Turns a Reader, r, into an async iterator.

f
Deno.iterSync
deprecated

Turns a ReaderSync, r, into an iterator.

Send a signal to process under given pid. The value and meaning of the signal to the process is operating system and process dependant. Signal provides the most common signals. Default signal is "SIGTERM".

Creates newpath as a hard link to oldpath.

Synchronously creates newpath as a hard link to oldpath.

Listen announces on the local transport address.

Listen announces on the local transport address.

Listen announces on the local transport address over TLS (transport layer security).

Returns an array containing the 1, 5, and 15 minute load averages. The load average is a measure of CPU and IO utilization of the last one, five, and 15 minute periods expressed as a fractional number. Zero means there is no load. On Windows, the three values are always the same and represent the current load, not the 1, 5 and 15 minute load averages.

Resolves to a Deno.FileInfo for the specified path. If path is a symlink, information for the symlink will be returned instead of what it points to.

Synchronously returns a Deno.FileInfo for the specified path. If path is a symlink, information for the symlink will be returned instead of what it points to.

Creates a new temporary directory in the default directory for temporary files, unless dir is specified. Other optional options include prefixing and suffixing the directory name with prefix and suffix respectively.

Synchronously creates a new temporary directory in the default directory for temporary files, unless dir is specified. Other optional options include prefixing and suffixing the directory name with prefix and suffix respectively.

Creates a new temporary file in the default directory for temporary files, unless dir is specified.

Synchronously creates a new temporary file in the default directory for temporary files, unless dir is specified.

Returns an object describing the memory usage of the Deno process and the V8 subsystem measured in bytes.

Receive metrics from the privileged side of Deno. This is primarily used in the development of Deno. Ops, also called bindings, are the go-between between Deno JavaScript sandbox and the rest of Deno.

Creates a new directory with the specified path.

Synchronously creates a new directory with the specified path.

Returns an array of the network interface information.

Open a file and resolve to an instance of Deno.FsFile. The file does not need to previously exist if using the create or createNew open options. It is the caller's responsibility to close the file when finished with it.

Synchronously open a file and return an instance of Deno.FsFile. The file does not need to previously exist if using the create or createNew open options. It is the caller's responsibility to close the file when finished with it.

Returns the release version of the Operating System.

Read from a resource ID (rid) into an array buffer (buffer).

f
Deno.readAll
deprecated

Read Reader r until EOF (null) and resolve to the content as Uint8Array`.

f
Deno.readAllSync
deprecated

Synchronously reads Reader r until EOF (null) and returns the content as Uint8Array.

Reads the directory given by path and returns an async iterable of Deno.DirEntry.

Synchronously reads the directory given by path and returns an iterable of Deno.DirEntry.

Reads and resolves to the entire contents of a file as an array of bytes. TextDecoder can be used to transform the bytes to string if required. Reading a directory returns an empty data array.

Synchronously reads and returns the entire contents of a file as an array of bytes. TextDecoder can be used to transform the bytes to string if required. Reading a directory returns an empty data array.

Resolves to the full path destination of the named symbolic link.

Synchronously returns the full path destination of the named symbolic link.

Synchronously read from a resource ID (rid) into an array buffer (buffer).

Asynchronously reads and returns the entire contents of a file as an UTF-8 decoded string. Reading a directory throws an error.

Synchronously reads and returns the entire contents of a file as an UTF-8 decoded string. Reading a directory throws an error.

Resolves to the absolute normalized path, with symbolic links resolved.

Synchronously returns absolute normalized path, with symbolic links resolved.

Make the timer of the given id block the event loop from finishing.

Removes the named file or directory.

Removes the given signal listener that has been registered with Deno.addSignalListener.

Synchronously removes the named file or directory.

Renames (moves) oldpath to newpath. Paths may be files or directories. If newpath already exists and is not a directory, rename() replaces it. OS-specific restrictions may apply when oldpath and newpath are in different directories.

Synchronously renames (moves) oldpath to newpath. Paths may be files or directories. If newpath already exists and is not a directory, renameSync() replaces it. OS-specific restrictions may apply when oldpath and newpath are in different directories.

Performs DNS resolution against the given query, returning resolved records.

Returns a map of open resource IDs (rid) along with their string representations. This is an internal API and as such resource representation has unknown type; that means it can change any time and should not be depended upon.

Spawns new subprocess. RunOptions must contain at a minimum the opt.cmd, an array of program arguments, the first of which is the binary.

Seek a resource ID (rid) to the given offset under mode given by whence. The call resolves to the new position within the resource (bytes from the start).

Synchronously seek a resource ID (rid) to the given offset under mode given by whence. The new position within the resource (bytes from the start) is returned.

Serves HTTP requests with the given handler.

Provides an interface to handle HTTP request and responses over TCP or TLS connections. The method returns an HttpConn which yields up RequestEvent events, which utilize the web platform standard Request and Response objects to handle the request.

Shutdown socket send operations.

f
Deno.spawn
deprecated
f
Deno.spawnChild
deprecated
f
Deno.spawnSync
deprecated

Start TLS handshake from an existing connection using an optional list of CA certificates, and hostname (default is "127.0.0.1"). Specifying CA certs is optional. By default the configured root certificates are used. Using this function requires that the other end of the connection is prepared for a TLS handshake.

Resolves to a Deno.FileInfo for the specified path. Will always follow symlinks.

Synchronously returns a Deno.FileInfo for the specified path. Will always follow symlinks.

Creates newpath as a symbolic link to oldpath.

Creates newpath as a symbolic link to oldpath.

Displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the kernel.

Register a test which will be run when deno test is used on the command line and the containing module looks like a test module.

Truncates (or extends) the specified file, to reach the specified len. If len is not specified then the entire file contents are truncated.

Synchronously truncates (or extends) the specified file, to reach the specified len. If len is not specified then the entire file contents are truncated.

Returns the user id of the process on POSIX platforms. Returns null on Windows.

Retrieve the process umask. If mask is provided, sets the process umask. This call always returns what the umask was before the call.

Make the timer of the given id not block the event loop from finishing.

Allows "hijacking" the connection that the request is associated with. This can be used to implement protocols that build on top of HTTP (eg. WebSocket).

Allows "hijacking" the connection that the request is associated with. This can be used to implement protocols that build on top of HTTP (eg. WebSocket).

Upgrade an incoming HTTP request to a WebSocket.

Changes the access (atime) and modification (mtime) times of a file system object referenced by path. Given times are either in seconds (UNIX epoch time) or as Date objects.

Synchronously changes the access (atime) and modification (mtime) times of a file system object referenced by path. Given times are either in seconds (UNIX epoch time) or as Date objects.

Watch for file system events against one or more paths, which can be files or directories. These paths must exist already. One user action (e.g. touch test.file) can generate multiple file system events. Likewise, one user action can result in multiple file paths in one event (e.g. mv old_name.txt new_name.txt).

Write to the resource ID (rid) the contents of the array buffer (data).

f
Deno.writeAll
deprecated

Write all the content of the array buffer (arr) to the writer (w).

Synchronously write all the content of the array buffer (arr) to the writer (w).

Write data to the given path, by default creating a new file if needed, else overwriting.

Synchronously write data to the given path, by default creating a new file if needed, else overwriting.

Synchronously write to the resource ID (rid) the contents of the array buffer (data).

Write string data to the given path, by default creating a new file if needed, else overwriting.

Synchronously write string data to the given path, by default creating a new file if needed, else overwriting.

Interfaces

Basic authentication credentials to be used with a Deno.Proxy server when specifying Deno.CreateHttpClientOptions.

The interface for defining a benchmark test using Deno.bench.

If Deno.resolveDns is called with "CAA" record type specified, it will resolve with an array of objects with this interface.

I
Deno.ChildStatus
deprecated

An abstract interface which when implemented provides an interface to close files/resources that were previously opened.

Options which can be set when calling {@link Deno.command}.

The interface returned from calling {@link Command.output} or {@link Command.outputSync} which represents the result of spawning the child process.

The options used when creating a Deno.HttpClient.

A generic transport listener for message-oriented protocols.

Information about a directory entry returned from Deno.readDir and Deno.readDirSync.

A dynamic library resource. Use Deno.dlopen to load a dynamic library and return this interface.

An interface containing methods to interact with the process environment variables.

The permission descriptor for the allow-env permissions, which controls access to being able to read and write to the process environment variables as well as access other information about the environment. The option variable allows scoping the permission to a specific environment variable.

The permission descriptor for the allow-ffi permissions, which controls access to loading foreign code and interfacing with it via the Foreign Function Interface API available in Deno. The option path allows scoping the permission to a specific path on the host.

Provides information about a file and is returned by Deno.stat, Deno.lstat, Deno.statSync, and Deno.lstatSync or from calling stat() and statSync() on an Deno.FsFile instance.

The interface for a foreign function as defined by its parameter and result types.

A foreign library interface descriptor.

Represents a unique file system event yielded by a Deno.FsWatcher.

Returned by Deno.watchFs. It is an async iterator yielding up system events. To stop watching the file system by calling .close() method.

The permission descriptor for the allow-hrtime permission, which controls if the runtime code has access to high resolution time. High resolution time is consider sensitive information, because it can be used by malicious code to gain information about the host that it might otherwise have access to.

A custom HttpClient for use with fetch function. This is designed to allow custom certificates or proxies to be used with fetch().

The async iterable that is returned from Deno.serveHttp which yields up RequestEvent events, representing individual requests on the HTTP server connection.

Option which can be specified when performing Deno.inspect.

Options which can be set when using Deno.mkdir and Deno.mkdirSync.

If Deno.resolveDns is called with "MX" record type specified, it will return an array of objects with this interface.

If Deno.resolveDns is called with "NAPTR" record type specified, it will return an array of objects with this interface.

The permission descriptor for the allow-net permissions, which controls access to opening network ports and connecting to remote hosts via the network. The option host allows scoping the permission for outbound connection to a specific host and port.

The information for a network interface returned from a call to Deno.networkInterfaces.

Options which can be set when doing Deno.open and Deno.openSync.

A set of options which can define the permissions within a test or worker context at a highly specific level.

The interface which defines what event types are supported by PermissionStatus instances.

The definition of a proxy when specifying Deno.CreateHttpClientOptions.

An abstract interface which when implemented provides an interface to read bytes into an array buffer asynchronously.

An abstract interface which when implemented provides an interface to read bytes into an array buffer synchronously.

Options which can be set when using Deno.readFile or Deno.readFileSync.

The permission descriptor for the allow-read permissions, which controls access to reading resources from the local host. The option path allows scoping the permission to a specific path (and if the path is a directory any sub paths).

Options which can be set when using Deno.remove and Deno.removeSync.

The event yielded from an HttpConn which represents an HTTP request from a remote client.

Options which can be set when using Deno.resolveDns.

Options which can be used with Deno.run.

The permission descriptor for the allow-run permission, which controls access to what sub-processes can be executed by Deno. The option command allows scoping the permission to a specific executable.

An abstract interface which when implemented provides an interface to seek within an open file/resource asynchronously.

An abstract interface which when implemented provides an interface to seek within an open file/resource synchronously.

Options which can be set when calling Deno.serve.

Additional options which are used when opening a TLS (HTTPS) server.

If Deno.resolveDns is called with "SOA" record type specified, it will return an array of objects with this interface.

I
Deno.SpawnOutput
deprecated

If Deno.resolveDns is called with "SRV" record type specified, it will return an array of objects with this interface.

Options that can be used with symlink and symlinkSync.

The permission descriptor for the allow-sys permissions, which controls access to sensitive host system information, which malicious code might attempt to exploit. The option kind allows scoping the permission to a specific piece of information.

Information returned from a call to Deno.systemMemoryInfo.

Context that is passed to a testing function, which can be used to either gain information about the current test, or register additional test steps within the current test.

Specialized listener that accepts TLS connections.

Unstable options which can be set when opening a datagram listener via Deno.listenDatagram.

Unstable options which can be set when opening a Unix listener via Deno.listen or Deno.listenDatagram.

Definition of a unsafe callback function.

Options which can be set when performing a Deno.upgradeWebSocket upgrade of a Request

The object that is returned from a Deno.upgradeWebSocket request.

Options for writing to a file.

The permission descriptor for the allow-write permissions, which controls access to writing to resources from the local host. The option path allow scoping the permission to a specific path (and if the path is a directory any sub paths).

An abstract interface which when implemented provides an interface to write bytes from an array buffer to a file/resource asynchronously.

An abstract interface which when implemented provides an interface to write bytes from an array buffer to a file/resource synchronously.

Type Aliases

Additional information for FsEvent objects with the "other" kind.

All supported types for interfacing with foreign functions.

Permission descriptors which define a permission and can be queried, requested, or revoked.

The name of a privileged feature which needs permission.

Options which define the permissions within a test or worker context.

The current status of the permission:

Pointer type depends on the architecture and actual pointer value.

The status resolved from the .status() method of a Deno.Process instance.

The type of the resource record to resolve via DNS using Deno.resolveDns.

A handler for HTTP requests. Consumes a request and returns a response.

Operating signals which can be listened for or sent to sub-processes. What signals and what their standard behaviors are OS dependent.