DOS ain't dead

Hi,
I just wrote the help version of lzip and noticed that there is a problem with 8.3.
When I try lzip abcdefgh.123 I get an error message:
Can't create output file abcdefgh.123.lz

It only works when I activate doslfn.

Is there a workaround? Am I right, when I say that lzip is almost unusable for DOS?

> Hi,
> I just wrote the help version of lzip and noticed that there is a problem
> with 8.3.
> When I try lzip abcdefgh.123 I get an error message:
> Can't create output file abcdefgh.123.lz

Uh, is that my old "lzip 1.20" build from 2018?

> It only works when I activate doslfn.
>
> Is there a workaround? Am I right, when I say that lzip is almost unusable
> for DOS?

Help says: -o, --output=<file>

Usage is: lzip -o abcdefgh.lz abcdefgh.123

---
Forum admin

> Hi,
> I just wrote the help version of lzip and noticed that there is a problem
> with 8.3.
> When I try lzip abcdefgh.123 I get an error message:
> Can't create output file abcdefgh.123.lz
>
> It only works when I activate doslfn.
>
> Is there a workaround? Am I right, when I say that lzip is almost unusable
> for DOS?

Still not sure what I do wrong. Sorry for so many pictures, but I hope it clears what I am talking about.

> Still not sure what I do wrong. Sorry for so many pictures, but I hope it
> clears what I am talking about.
>
attrib uninstall.lz -r

> Still not sure what I do wrong. Sorry for so many pictures, but I hope it
> clears what I am talking about.

I can confirm this behavior on my system for my lzip 1.9 and lzip 1.20 ports.

-o or --output=file only works when reading from stdin, as the help screen says.

When reading from a file, lzip always takes the input file name and appends .lz.

---
Forum admin

> > Still not sure what I do wrong. Sorry for so many pictures, but I hope
> it
> > clears what I am talking about.
>
> I can confirm this behavior on my system for my lzip 1.9 and lzip 1.20
> ports.
>
> -o or --output=file only works when reading from
> stdin, as the help screen says.
>
> When reading from a file, lzip always takes the input file name and appends
> .lz.

From main.cc:

const struct { const char * from; const char * to; } known_extensions[] = {
  { ".lz",  ""     },
  { ".tlz", ".tar" },
  { 0,      0      } };

[...]

void set_c_outname( const std::string & name, const bool force_ext,
                    const bool multifile )
  {
  output_filename = name;
  if( multifile ) output_filename += "00001";
  if( force_ext || multifile || extension_index( output_filename ) < 0 )
    output_filename += known_extensions[0].from;
  }

[...]


---
Forum admin

> > Still not sure what I do wrong. Sorry for so many pictures, but I hope
> it
> > clears what I am talking about.
>
> I can confirm this behavior on my system for my lzip 1.9 and lzip 1.20
> ports.
>
> -o or --output=file only works when reading from
> stdin, as the help screen says.
>
> When reading from a file, lzip always takes the input file name and appends
> .lz.

Wait! It's not completely unusable.
The solution is already noted above:

Compress: lzip -k -o example < example.exe
-> This will create example.lz.

Decompress: lzip -k -d -o example2.exe < example.lz

Note the redirection operators <.

---
Forum admin

> > > Still not sure what I do wrong. Sorry for so many pictures, but I hope
> > it
> > > clears what I am talking about.
> >
> > I can confirm this behavior on my system for my lzip 1.9 and lzip 1.20
> > ports.
> >
> > -o or --output=file only works when reading
> from
> > stdin, as the help screen says.
> >
> > When reading from a file, lzip always takes the input file name and
> appends
> > .lz.
>
> Wait! It's not completely unusable.
> The solution is already noted above:
>
> Compress: lzip -k -o example < example.exe
> -> This will create example.lz.
>
> Decompress: lzip -k -d -o example2.exe < example.lz
>
> Note the redirection operators <.

Ok, thanks for this information, I will modify the help file, but how do you know a year later that this file was an exe file and not a gif?
Especially if you have a gif and a pdf and an exe file with the same name in the same folder as it is, eg, in vim?

> > > > Still not sure what I do wrong. Sorry for so many pictures, but I
> hope
> > > it
> > > > clears what I am talking about.
> > >
> > > I can confirm this behavior on my system for my lzip 1.9 and lzip 1.20
> > > ports.
> > >
> > > -o or --output=file only works when reading
> > from
> > > stdin, as the help screen says.
> > >
> > > When reading from a file, lzip always takes the input file name and
> > appends
> > > .lz.
> >
> > Wait! It's not completely unusable.
> > The solution is already noted above:
> >
> > Compress: lzip -k -o example < example.exe
> > -> This will create example.lz.
> >
> > Decompress: lzip -k -d -o example2.exe < example.lz
> >
> > Note the redirection operators <.
>
> Ok, thanks for this information, I will modify the help file, but how do
> you know a year later that this file was an exe file and not a gif?
> Especially if you have a gif and a pdf and an exe file with the same name
> in the same folder as it is, eg, in vim?
The only way to handle it is to create tar.lz?

> > Wait! It's not completely unusable.
> > The solution is already noted above:
> >
> > Compress: lzip -k -o example < example.exe
> > -> This will create example.lz.
> >
> > Decompress: lzip -k -d -o example2.exe < example.lz
> >
> > Note the redirection operators <.
>
> Ok, thanks for this information, I will modify the help file, but how do
> you know a year later that this file was an exe file and not a gif?
> Especially if you have a gif and a pdf and an exe file with the same name
> in the same folder as it is, eg, in vim?

lzip can't remove the DOS 8.3 limitation. So, this is left as an exercise to the user. One could rename example.lz to example.xlz for an .exe file.

---
Forum admin

> > Ok, thanks for this information, I will modify the help file, but how do
> > you know a year later that this file was an exe file and not a gif?
> > Especially if you have a gif and a pdf and an exe file with the same
> > name in the same folder as it is, eg, in vim?
>
> The only way to handle it is to create tar.lz?

You're on the right track. The preferred way to use lzip is to compress containers.
So, at first, you tar your desired files into a .tar archive, then create a .tlz from this tar container.

---
Forum admin

> > > Ok, thanks for this information, I will modify the help file, but how
> do
> > > you know a year later that this file was an exe file and not a gif?
> > > Especially if you have a gif and a pdf and an exe file with the same
> > > name in the same folder as it is, eg, in vim?
> >
> > The only way to handle it is to create tar.lz?
>
> You're on the right track. The preferred way to use lzip is to compress
> containers.
> So, at first, you tar your desired files into a .tar archive,
> then create a .tlz from this tar container.

Thanks for feedback!