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Section Seven - Filer reference

Section Seven - Filer reference

May 07, 2020

 

This section describes the more advanced features and commands of the Filer popdown, and should be read in conjunction with The Filer. The features described here include:

Here, you will find the following chapters:

Describes filename syntax, filename extensions, directory structure, device specifications and wildcards.

Describes commands that provide facilities for creating directories, manipulating files within the hierarchical directory structure.

Describes how to use the Command Line Interpreter with text files, reference of special commands for the CLI, redirecting of I/O and how to utilize this for editing BBC BASIC programs in PipeDream.

A little story about Directories

Users may not understand the value of using "The Filing System Hierarchical System," until it is too late. Here is a fictitious example showing what 482 files could look like if they are just dumped into the flash card. There are no directories, and when using EPROMs or Flashcards, no date is stored. The order of the files are known. the first file saved is on Page 1 top left-hand corner and the last file is on Page 2, bottom right-hand corner. There is no way of knowing what each file contains. Perhaps the answer is in the file name.

Page 1

Page 2

NOTE

The numbers on the left column indicates the file size.

File names

The first 6 file-names were on the flash card to start with, but then there are

286 RECEIPT
863 DEBT
739 FONENOS2

Now what you need to ask yourself when choosing a file name is,

will I remember what this would be about in 10 years time,

just by looking at the file name? If I asked you now, what would you say for the first one, "that's a receipt?" Now that is a good start, but, what was it for? Who was it from? When was it issued? The only way of knowing that is by opening the file and having a look.

Other file names down the list include

123 5
141 4
140 3

These file names could mean anything. You can have 12 characters to describe what the file is and the first file here is 5. There are some other clues. File 5 was saved before File 4 and File 3, but again without knowing what all these files are the only way again of knowing what they are is again by opening them and having a look.

Q & A

Q When is the best time to sort out your file names?
Q When is the best time to sort out your directories?

A At the beginning 

Looking at the file name  286 RECEIPT and then the questions we asked about it i.e. what was it for? Who was it from? When was it issued? These answers may be put into the Directories. i.e.

/BATHROOM/PLUMBER/20150714/RECEIPT

This now shows that the receipt was for the PLUMBER who did some work in the BATHROOM on the 14th July 2015.

Writing Dates

If the date is written backwards, i.e. YYYYMMDD the numbers can be easily sorted.

Do not think, I will use this name for now and will change it later. This example was based on 'real-life,' the file names never got changed. 

Specifying file names in full

The Filing System Hierarchical System

The Filing System Hierarchical System

The Filing System Hierarchical System looks like an upside down tree with the Device at the top.
Underneath that can be either a Directory or a filename,
Underneath that can be either a Directory or a filename,
and so on ... 

The full form of a file name is
:DEVICE I DIRECTORY I DIRECTORY I .... /filename
where
DEVICE is one of the specification listed below
DIRECTORY and filename are each of the form
name.extension
consisting of a name of up to 12 letters or digits, followed by an optional extension of up to three letters or digits, DIRECTORY is a directory name subject to the same constraints as filename.

All ISO characters (such as é and å) are allowed in filenamesOZ4.7.

The following extensions are used for system functions:

.sgn

For

symb_square.png

+K and

symb_square.png

+S CLI files

.CLI

For BOOT.CLI; see CLI files section below

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