.. RST source for alf(1) man page. Convert with:
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===
alf
===

-------------------------------
create Atari 8-bit ALF archives
-------------------------------

:Manual section: 1
:Manual group: Urchlay's Atari 8-bit Tools
:Date: |date|
:Version: |version|

SYNOPSIS
========

alf [**--help**] | [**-a** | **-o** ] [**-t[dgz]**] *alf-file* *file* [*file* ...]

DESCRIPTION
===========

**alf** creates *ALF* archives.

*ALF* is a compressed archive format similar to **arc**\(1), though
not compatible with it. It was used on the Atari 8-bit platform
beginning in the late 1980s. The Atari executables are **LZ.COM**
for the compressor and **DZ.COM** for the decompressor. **alf** is a
rewrite of **LZ.COM** for modern operating systems, with added features.

By default, the *alf-file* is created, and the *file*\s are compressed
and added to it. If *alf-file* already existed, it is backed up by adding
a **~** to the filename.

The **ALF** file format only supports uppercase "8.3" filenames
(Atari DOS or MS-DOS style), and does not support subdirectories. The
filenames you give will be stored in the **ALF** file uppercased
and truncated to fit the 8.3 scheme. This could result in duplicate
filenames in the archive, if you're not careful.

OPTIONS
=======

-a
  Append to *alf-file*. The files are added to the end of the archive. Be
  careful not to add a file with the same name as as existing member of
  the archive. If *alf-file* doesn't exist, it will be created. No backup
  is made with **-a**.

.. append to alf file.

-A
  Convert line endings and tabs from ASCII to ATASCII in all input
  files. This will corrupt any executables or non-text data files,
  so use with caution. There is no way to autodetect text files,
  unlike **unalf**.

.. convert EOLs and tabs in all input files.

-h, --help
   Show built-in help message.

.. show this help message.

-o
  Overwrite *alf-file* if it exists; do not make a **~** backup.

.. overwrite alf file if exists (do not create file~ backup).

-td
  Use default **LZ.COM** timestamps (8 Dec 82  12:24).

.. use default LZ.COM timestamps.

-tu
  Use UTC for timestamps (default is local timezone).

.. use UTC timestamps.

-tz
  Use zero for timestamps (0 ??? 80  12:00a).

.. use zero timestamps.

-V, --version
  Show **unalf** version number and exit.

.. show version number.

.. ENDOPTS

EXIT STATUS
===========

0
  Success.

1
  Fatal error (I/O or bad command-line arguments).

NOTES
=====

Compatibility
-------------

This **alf** is *intended* to be 100% compatible with the original
Atari **LZ.COM** aka **ALF.COM**, with the following differences:

- There is no interactive mode. The file to create and the files to add
  must be given as command-line arguments.

- **LZ.COM** always appends to a file that already exists. This **alf**
  overwrites (making a backup) by default, and can append with the **-a**
  option.

- Turning the screen off for speed makes no sense on modern operating
  systems, so there's no option for that.

Note that **alf** is a complete reverse-engineered rewrite in C, *not*
a port of the original 6502 code as **unalf** is. It's still being
tested, and may still contain bugs.

File Size Limits
----------------

**alf** (and **LZ.COM**) have a 16MB file size limit. **uanlf**
actually can't handle files above about 15MB, if you compress one with
**alf**. Real Atari 8-bit files are never this large anyway, so it's
a pathological case. A real Atari would take hours or even days to
compress/decompress such files, and you'd have to have a hard disk and
a DOS capable of handling multi-megabyte files...

It's also impossible to compress empty (0-byte) files. **alf** will
skip them, if any are found.

Performance
-----------

Performance is *horrible*. This shouldn't be a real problem on
modern multi-GHz CPU, especially since most Atari 8-bit files are
small (usually under 64KB). Interestingly, it's not O(n^2), it scales
linearly, O(1): Compressing a 1.3MB text file takes 0.7 seconds on the
author's (rather modest) Intel i7 workstation, and a file 10x as large
takes approximately 10x as long (7 seconds). A 50KB file is almost
instantaneous, 0.05 seconds, which is more typical of the files you'd
actually use this with.

Timestamps
----------

The date/time stamps stored in the archive are the **mtime**\s of
the files (which is the same time **ls**\(1) shows, by default), and
your local timezone is assumed. Only a 2-digit year is displayed by
**unalf**, but the year stored in the *ALF* file doesn't have a Y2K
problem. It does, however, have a Y2108 problem...

COPYRIGHT
=========

The original AlfCrunch (**DZ.COM** and **LZ.COM**) for the Atari 8-bit
was released into the Public Domain. **alf** contains no code from
AlfCrunch.

**alf** is released under the WTPFL: Do WTF you want with this.

AUTHOR
======

The original AlfCrunch for the Atari 8-bit was written by Alfred, who
can be reached via the AtariAge.com forums with the username "Alfred".

This **alf** was written by B. Watson <urchlay@slackware.uk>.

SEE ALSO
========

**unalf**\(1), **alfls**\(1)

.. include:: manftr.rst