# Titanium.IOStream > IOStream is the interface that all stream types implement. - Source: https://titaniumsdk.com/docs/sdk/13.4.0/Titanium.IOStream - Titanium SDK version: 13.4.0 - Kind: proxy - Platforms: Android, iPhone, iPad, macOS - Since: Titanium SDK Android 1.7, iPhone 1.7, iPad 1.7, macOS 9.2.0 - Extends: Titanium.Proxy - Inheritance: Titanium.Proxy See the [Titanium.Stream](https://titaniumsdk.com/docs/sdk/Titanium.Stream.md) module for related utility methods that support asynchronous I/O. ## Example: Write Data to a Stream This example demonstrates writing data to a stream. ``` js var outBuffer = Ti.createBuffer({data: "write me"}); // stream object could be socket, file, buffer or blob var outStream = Ti.Stream.createStream({mode: Ti.Stream.MODE_WRITE}); var bytesWritten = outStream.write(outBuffer); // writes entire buffer to stream Ti.API.info("Bytes written:" + bytesWritten); // should be 8 bytesWritten = outStream.write(outBuffer, 2, 5); // only writes "ite m" to stream Ti.API.info("Bytes written:" + bytesWritten); // should be 5 ``` ## Example: Read Data From a Stream This shows a simple example of reading data from a stream, one buffer full at a time. ``` js var size = 0; // read data one buffer full at a time while ((size = instream.read(buffer)) > -1) { // do something with the data here ... Ti.API.info("Read " + size + " bytes."); } ``` ## Example: Read Data With Offset and Length This example shows how to read data from a stream into a buffer. We assume that the `inStream` variable holds a previously initialized stream that contains the string, "World Titanium". ``` js var inBuffer = Ti.createBuffer({ value: "Hello [ ]" }); // Read the first 6 bytes from the stream to the buffer, starting at position 10. var bytesRead = inStream.read(inBuffer, 10, 6); Ti.API.info("Bytes read: " + bytesRead); Ti.API.info(inBuffer.toString()); // Read the next 8 bytes from the stream to the buffer, starting at position 8. bytesRead = inStream.read(inBuffer, 8, 8); Ti.API.info("Bytes read: " + bytesRead); Ti.API.info(inBuffer.toString()); ``` The second `read` overwrites the data from the first `read`, so the output looks like this: ``` [INFO] Bytes read: 6 [INFO] Hello [ World ] [INFO] Bytes read: 8 [INFO] Hello [ Titanium ] ``` ## Methods ### close - Platforms: Android, iPhone, iPad, macOS Closes this stream. Throws an exception on error. ### isReadable - Platforms: Android, iPhone, iPad, macOS Indicates whether this stream is readable. Returns: Boolean - True if stream is readable, false otherwise. ### isWritable - Platforms: Android, iPhone, iPad, macOS Indicates whether this stream is writable. Returns: Boolean - True if stream is writable, false otherwise. ### read - Platforms: Android, iPhone, iPad, macOS Reads data from this stream into a buffer. Takes an optional `resultsCallback` function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously. If `offset` and `length` are specified, data is written into the buffer starting at position `offset`. Data is read from this stream until one of the following occurs: * the end of this stream is reached * the end of the buffer is reached * a total of `length` bytes have been read from the stream If `offset` and `length` are omitted, data is written starting at the beginning of the buffer. When called synchronously: returns the number of bytes read, or -1 if the end of stream was reached before any data was read. Returns 0 when called asynchronously. Throws an exception on error. For example, if the `offset` value is past the last byte of `buffer`. Parameters: - `buffer` (Titanium.Buffer): Buffer to read stream data into. - `offset` (Number, optional): Offset into the buffer to start writing stream data. If specified, `length` must also be specified. Default: `0`. - `length` (Number, optional): Maximum number of bytes to read. If specified, `offset` must also be specified. Default: `Length of the supplied buffer.`. - `resultsCallback` (Callback, optional): Function to call with the results of the read operation. Returns: Number - Number of bytes read. ### write - Platforms: Android, iPhone, iPad, macOS Writes data from a buffer to this stream. Takes an optional `resultsCallback` function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously. If `offset` and `length` are specified, data is read from the buffer starting at `offset`. Bytes are read from the buffer and written to the stream until: * the end of the buffer is reached * `length` bytes have been written * the stream returns an error If `offset` and `length` are omitted, all of the data in the buffer is written to this stream. Returns the number of bytes actually written when called synchronously. Returns 0 when called asynchronously. Throws an exception if an error is encountered. Parameters: - `buffer` (Titanium.Buffer): Buffer to write to this stream. - `offset` (Number, optional): Offset in the buffer of the first byte to write to the stream. If specified, `length` must also be specified. Default: `0`. - `length` (Number, optional): Maximum number of bytes to write to the stream. If specified, `offset` must also be specified. Default: `Length of the supplied buffer.`. - `resultsCallback` (Callback, optional): Function to call with the results of the write operation. Returns: Number - Number of bytes written. ## Inherited members 7 members are inherited. Each is documented on the type that declares it. - [Titanium.Proxy](https://titaniumsdk.com/docs/sdk/13.4.0/Titanium.Proxy.md): `addEventListener`, `apiName`, `applyProperties`, `bubbleParent`, `fireEvent`, `lifecycleContainer`, `removeEventListener` --- - This corpus documents Titanium SDK 13.4.1. Anything here that does not name a version describes 13.4.1. - Titanium is maintained by TiDev. The Appcelerator toolchain is retired: there is no `appc` CLI, no Appcelerator Studio and no hosted build service. The supported CLI is `titanium` on npm, invoked as `ti`.