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Merge pull request #218 from xexyl/1993-lmfjyh

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Landon Curt Noll authored and GitHub committed 2023-03-30 12:17:39 -07:00
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## To build: ## To build:
make all This entry will not compile with gcc < 2.3.3 as it relied on a bug which was
fixed in gcc 2.3.3 which was fixed a very long time ago now. If you have such a
compiler you can run `make all`.
NOTE: This entry will not compile on modern systems because it relies on a **WARNING**: Trying to compile this entry without the affected gcc will also
compiler bug which was fixed in gcc 2.3.3 (a very long time ago now). Trying to make a bogus file on your file system. To delete it you can use the inode
compile it will also make a bogus file on your file system. To delete it you option `-inum` with `find` with the delete option after finding the inode with
can use the inode option `-inum` with `find` with the delete option after `ls -li` or else use a GUI to do it. Should you wish to try compiling it you
finding the inode with `ls -li`. might see something like:
### To run NOTE: This will not compile when using modern compilers because
it relies on a compiler bug which was fixed in gcc 2.3.3 (a very
long time ago now).
rm -f \"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c
cp lmfjyh.c \"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c
cc -std=gnu90 -Wall -Wextra -pedantic -include stdio.h -O3 \
\"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c -o lmfjyh
Undefined symbols for architecture arm64:
"_main", referenced from:
implicit entry/start for main executable
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [lmfjyh] Error 1
and the bogus file will be:
";main(){puts("Hello World!");}char*C=".c
For an explanation of why this is see the author's comments.
## To run:
If you have gcc < 2.3.3:
./lmfjyh ./lmfjyh
## Judges' comments ## Judges' comments:
See the Makefile for details.
There's more than one way to get around disk quotas. :-) There's more than one way to get around disk quotas. :-)
## Author's comments ## Author's comments;
"Practical and efficient method of compressing source code" "Practical and efficient method of compressing source code".
1. Introduction ### Introduction
I will shortly present a totally new compression method. I will shortly present a totally new compression method.
It may be used to compress any types of files, but it works It may be used to compress any types of files, but it works
best with C-source code. best with C-source code.
As an example, I have taken a simple "Hello world!" program As an example, I have taken a simple "Hello world!" program
that should be familiar to all C-programmers. that should be familiar to all C-programmers.
Listing 1. A simple "Hello World" program: Listing 1. A simple "Hello World" program:
main()
{
puts("Hello World!");
}
2. Packing method main()
{
Normally a file name is used only to identify the file, puts("Hello World!");
but this new revolutionary method introduces a totally new concept: }
THE FILE NAME IS THE PROGRAM. There is no need to waste
valuable disk space to store source code. The program is
embedded in the file name, only a minor portion of it
is inside the file.
Listing 2. Compressed "Hello world":
char*_=__FILE__;
Listing 3. Code embedded in the file name: ### Packing method
";main(){puts("Hello World!");}char*C=".c Normally a file name is used only to identify the file,
but this new revolutionary method introduces a totally new concept:
THE FILE NAME IS THE PROGRAM. There is no need to waste
valuable disk space to store source code. The program is
embedded in the file name, only a minor portion of it
is inside the file.
Listing 2. Compressed "Hello world":
The sample program in listing 1 is 36 bytes long. By using the new char*_=__FILE__;
compression method, the example program may be squeezed to sixteen
bytes. In the example the compression ratio is 2:1. It is evident
that the longer the program is, the better the compression ratio
is. The maximum compression ratio in a UNIX environment is 254:16
which equals approximately to 16:1. By using the method a one
megabyte of source code can be compressed to 64 kilobytes.
One might easily think that the program could be compressed to a
single byte by writing a one character long preprocessor directive
in the source file and defining the actual source code in the
command line, eg. 'cc hello.c -DX=main(){puts...'. With this
method nothing is gained, since the compiling commands must be
stored in a file, and that takes even more space than writing the
code in a source file as presented in listing 1.
3. Packing files in a UNIX environment Listing 3. Code embedded in the file name:
In a UNIX environment it is possible to write almost any program by
including the code in file names. Since '/' is used to separate
path components and cannot therefore exist in a file name, all
features of C-language cannot be used.
In C, the '/' is used as a division operator and it may also be a
part of a comment start and end identifier. This is, however, not a
dangerous limitation, since practice has shown that comments are
almost totally unnecessary. A real programmer can more easily
understand pure source code, and misleading comments are
disastrous. The division operation may be replaced with pow(x, -1)
and multiplication when using real numbers or with div() function
when using integers.
Large programs must be separated into small modules. This enforces
people to write better programs, since monolithic programming style
cannot be used. Program development will also be faster, no extra
code need not be recompiled after changes have been made.
4. Usage with currently available tools ";main(){puts("Hello World!");}char*C=".c
I have tested how well this new method works with currently
available programming tools.
Any ANSI conforming C-compiler that runs under a REAL operating The sample program in listing 1 is 36 bytes long. By using the new
system should be able to compile the code. (there may be problems compression method, the example program may be squeezed to sixteen
with some older UNIX variants) bytes. In the example the compression ratio is 2:1. It is evident
that the longer the program is, the better the compression ratio
is. The maximum compression ratio in a UNIX environment is 254:16
which equals approximately to 16:1. By using the method a one
megabyte of source code can be compressed to 64 kilobytes.
4.1. Compilers: One might easily think that the program could be compressed to a
single byte by writing a one character long preprocessor directive
in the source file and defining the actual source code in the
command line, eg. 'cc hello.c -DX=main(){puts...'. With this
method nothing is gained, since the compiling commands must be
stored in a file, and that takes even more space than writing the
code in a source file as presented in listing 1.
### Packing files in a UNIX environment
In a UNIX environment it is possible to write almost any program by
including the code in file names. Since '/' is used to separate
path components and cannot therefore exist in a file name, all
features of C-language cannot be used.
In C, the `/` is used as a division operator and it may also be a
part of a comment start and end identifier. This is, however, not a
dangerous limitation, since practice has shown that comments are
almost totally unnecessary. A real programmer can more easily
understand pure source code, and misleading comments are
disastrous. The division operation may be replaced with `pow(x, -1)`
and multiplication when using real numbers or with `div()` function
when using integers.
Large programs must be separated into small modules. This enforces
people to write better programs, since monolithic programming style
cannot be used. Program development will also be faster, no extra
code need not be recompiled after changes have been made.
### Usage with currently available tools
I have tested how well this new method works with currently
available programming tools.
Any ANSI conforming C-compiler that runs under a REAL operating
system should be able to compile the code. (there may be problems
with some older UNIX variants)
### Compilers:
These worked:
These worked:
gcc versions 2.0, 2.1, 2.3.2 (ld failed at AIX with gcc 2.1) gcc versions 2.0, 2.1, 2.3.2 (ld failed at AIX with gcc 2.1)
cc (HP-UX) cc (HP-UX)
cc (VAX) cc (VAX)
These failed miserably: These failed miserably:
cc (SunOs/Solaris) - could not start cpp properly cc (SunOs/Solaris) - could not start cpp properly
cc/xlc (AIX) - could not open source cc/xlc (AIX) - could not open source
4.2. Other tools: ### Other tools:
4.2.1 Debuggers: (tested at SunOs 4.1.2) #### Debuggers: (tested at SunOs 4.1.2)
dbx - Quit with a very 'informative' error message: dbx - Quit with a very 'informative' error message:
"dbx: fatal error: Is a directory" "dbx: fatal error: Is a directory"
gdb - Printed almost the same error message ":Is a directory". gdb - Printed almost the same error message ":Is a directory".
It was, however, possible to step through the code but It was, however, possible to step through the code but
not list it. not list it.
4.2.2 Lints: #### Lints
- None of the lints at tested environments were able None of the lints tested environments were able to parse the file.
to open the file.
5. Conclusions ### Conclusions
The method can be used to compress any types of files, actually the The method can be used to compress any types of files, actually the
compression ratios are even better when compressing other files compression ratios are even better when compressing other files
than C-source. For example plain text files may be compressed with than C-source. For example plain text files may be compressed with
INFINITE compression ratio. It is trivial task to compress a 100 INFINITE compression ratio. It is trivial task to compress a 100
kilobytes long text file in about 400 files whose lengths are zero kilobytes long text file in about 400 files whose lengths are zero
bytes. The drawback is that the files must be unpacked before they bytes. The drawback is that the files must be unpacked before they
can be used, so a large amount of temporary disk space is needed, can be used, so a large amount of temporary disk space is needed,
while C-source is totally usable in the compressed form. while C-source is totally usable in the compressed form.
Evidently, there is a long way to go before this new programming Evidently, there is a long way to go before this new programming
technique may be widely used, since currently there are only few technique may be widely used, since currently there are only few
tools supporting it. The advantages over the traditional methods tools supporting it. The advantages over the traditional methods
are, however, so great that there is no doubt that this method will are, however, so great that there is no doubt that this method will
be new standard. be new standard.
## Copyright and CC BY-SA 4.0 License: ## Copyright and CC BY-SA 4.0 License: