In this section:
This standard call-back is used with %eb (Edit Box) and takes a character string argument containing a file pattern (e.g. '*.TXT'). A second character string argument (called fname say) is required for the resultant file name (of size 129). A standard Windows 'file open' dialog is displayed and the resultant file is written to fname. The file is then displayed in a %eb edit box that is included in the current format window, replacing any text already there. This standard call-back must only be used in a format window containing one and only one %eb edit box. The corresponding edit box is usually supplied with a buffer length of zero when it is set up, so that the system allocates the buffer and adjusts its size as necessary.
An example program appears in A simple text editor.