How to Install a Return Port

To install a Return Port, you must first open the wall and insert it into a circular hole. The Return Port should be pushed into the hole with a circular motion, pushing part of the Liner outside of the wall. Cut the threads of the Return Port by an x, but avoid cutting too deeply, since this may leave a bigger hole than the gasket. After that, install the pipe and the return port. Let’s go over the process step by step.


Read-data and read-all-data are the two common ways to retrieve data from memory. Both return values have several properties. The first one is an address of a newly-allocated memory buffer, while the second one contains an integer indicating how many bytes were actually transferred. Read-data and read-all-data are useful for retrieving data from memory in large blocks. This procedure is similar to the read-data and write-all-data procedures except that it returns null if any error occurred.

The read-data method returns the number of bytes in the output buffer. If you use the read-data method to retrieve data from a file, the port will advance past the last character it has already read. The get-string method returns the string containing characters before the line-feed. Read-data is also useful for retrieving data from a memory card. However, you should not use read-data on the return port on your main application.

Read-data on return port uses a signal to indicate whether or not data is being written to the port. The signal bytesWritten() emits when a byte has been successfully written to the serial port. The readyRead() method blocks until new data is ready to be read. It timeouts after msecs milliseconds. The default timeout is 30000 milliseconds. If the time limit has been exceeded, the Read-data function returns False.


A write-ready return port is a convenient way to create a procedure or event that will be returned after it has completed writing data. This type of return port has a number of benefits, but is not as widely used as the write-out port. For example, writing to it in synchronization may cause busy waiting while the port performs the task. Also, write-out procedures may not be atomic. Write-out-specials are intended for such situations, but may be used in asynchronous applications.

The read-char method returns the first character beyond the token and the last character in the sequence of characters from the starting position. In order to obtain the complete token sequence, the event must become ready after the next read from the port. To do this, a procedure can use the semaphore-peek-evt. For port-provides-progress-evts?, it will produce a value of f. This means that port-provides-progress-evts? is not a valid argument.

As the name suggests, the write-ready function is the converse of the read-in function. It returns True when the port is ready to receive data, False otherwise. The function must return True or False depending on whether it is input or output. It is also important to note that write-ready should only be called when the port supports input and output. When a write-ready return port is called before a write-in operation, it must not block indefinitely, because the port will lose data in the process.


The End-of-file return port is a type of read-char or peek-char object that is returned by reading the last character of a file. This object is not to be confused with any other return values returned by read. The return value is false or true depending on whether the port is at the beginning of a line, or at the end of the file. This value is usually used to indicate when a file is no longer available for reading.

The “a” access type opens for reading and appending. If the file already exists, the EOF marker is removed. Then, any subsequent operations on the file will read from the file until it reaches the end. However, the “a+” access type also allows write operations at the end of a file. If the file has more characters than characters can be read, then a subsequent attempt to read the port will get the same character.

When opening a file with a fifo, a peer-waiting port is created. Write operations will block until the end of the file is opened. If this happens, sync can wait until the end of the file is opened. Similarly, a return-linefeed combination that is not followed by a linefeed will trigger an exception. Therefore, the end-of-file return port is used to indicate when a file is done reading.