Fix 1993/lmfjyh/README.md
Formatting fixes. Give more of a warning against this entry with gcc < 2.3.3 about it not working and creating a bogus file, referring to the author's comments as to the file name.
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## To build:
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make all
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This entry will not compile with gcc < 2.3.3 as it relied on a bug which was
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fixed in gcc 2.3.3 which was fixed a very long time ago now. If you have such a
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compiler you can run `make all`.
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NOTE: This entry will not compile on modern systems because it relies on a
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compiler bug which was fixed in gcc 2.3.3 (a very long time ago now). Trying to
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compile it will also make a bogus file on your file system. To delete it you
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can use the inode option `-inum` with `find` with the delete option after
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finding the inode with `ls -li`.
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**WARNING**: Trying to compile this entry without the affected gcc will also
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make a bogus file on your file system. To delete it you can use the inode
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option `-inum` with `find` with the delete option after finding the inode with
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`ls -li` or else use a GUI to do it. Should you wish to try compiling it you
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might see something like:
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### To run
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NOTE: This will not compile when using modern compilers because
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it relies on a compiler bug which was fixed in gcc 2.3.3 (a very
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long time ago now).
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rm -f \"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c
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cp lmfjyh.c \"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c
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cc -std=gnu90 -Wall -Wextra -pedantic -include stdio.h -O3 \
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\"\;main\(\)\{puts\(\"Hello\ World!\"\)\;\}char\*C=\".c -o lmfjyh
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Undefined symbols for architecture arm64:
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"_main", referenced from:
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implicit entry/start for main executable
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ld: symbol(s) not found for architecture arm64
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clang: error: linker command failed with exit code 1 (use -v to see invocation)
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make: *** [lmfjyh] Error 1
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and the bogus file will be:
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";main(){puts("Hello World!");}char*C=".c
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For an explanation of why this is see the author's comments.
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## To run:
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If you have gcc < 2.3.3:
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./lmfjyh
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## Judges' comments
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## Judges' comments:
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See the Makefile for details.
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There's more than one way to get around disk quotas. :-)
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## Author's comments
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## Author's comments;
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"Practical and efficient method of compressing source code"
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"Practical and efficient method of compressing source code".
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1. Introduction
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### Introduction
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I will shortly present a totally new compression method.
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It may be used to compress any types of files, but it works
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best with C-source code.
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I will shortly present a totally new compression method.
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It may be used to compress any types of files, but it works
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best with C-source code.
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As an example, I have taken a simple "Hello world!" program
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that should be familiar to all C-programmers.
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As an example, I have taken a simple "Hello world!" program
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that should be familiar to all C-programmers.
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Listing 1. A simple "Hello World" program:
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main()
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{
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puts("Hello World!");
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}
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Listing 1. A simple "Hello World" program:
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2. Packing method
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Normally a file name is used only to identify the file,
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but this new revolutionary method introduces a totally new concept:
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THE FILE NAME IS THE PROGRAM. There is no need to waste
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valuable disk space to store source code. The program is
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embedded in the file name, only a minor portion of it
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is inside the file.
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Listing 2. Compressed "Hello world":
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char*_=__FILE__;
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main()
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{
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puts("Hello World!");
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}
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Listing 3. Code embedded in the file name:
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### Packing method
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";main(){puts("Hello World!");}char*C=".c
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Normally a file name is used only to identify the file,
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but this new revolutionary method introduces a totally new concept:
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THE FILE NAME IS THE PROGRAM. There is no need to waste
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valuable disk space to store source code. The program is
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embedded in the file name, only a minor portion of it
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is inside the file.
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Listing 2. Compressed "Hello world":
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char*_=__FILE__;
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The sample program in listing 1 is 36 bytes long. By using the new
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compression method, the example program may be squeezed to sixteen
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bytes. In the example the compression ratio is 2:1. It is evident
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that the longer the program is, the better the compression ratio
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is. The maximum compression ratio in a UNIX environment is 254:16
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which equals approximately to 16:1. By using the method a one
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megabyte of source code can be compressed to 64 kilobytes.
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One might easily think that the program could be compressed to a
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single byte by writing a one character long preprocessor directive
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in the source file and defining the actual source code in the
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command line, eg. 'cc hello.c -DX=main(){puts...'. With this
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method nothing is gained, since the compiling commands must be
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stored in a file, and that takes even more space than writing the
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code in a source file as presented in listing 1.
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Listing 3. Code embedded in the file name:
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3. Packing files in a UNIX environment
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In a UNIX environment it is possible to write almost any program by
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including the code in file names. Since '/' is used to separate
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path components and cannot therefore exist in a file name, all
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features of C-language cannot be used.
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In C, the '/' is used as a division operator and it may also be a
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part of a comment start and end identifier. This is, however, not a
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dangerous limitation, since practice has shown that comments are
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almost totally unnecessary. A real programmer can more easily
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understand pure source code, and misleading comments are
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disastrous. The division operation may be replaced with pow(x, -1)
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and multiplication when using real numbers or with div() function
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when using integers.
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Large programs must be separated into small modules. This enforces
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people to write better programs, since monolithic programming style
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cannot be used. Program development will also be faster, no extra
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code need not be recompiled after changes have been made.
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";main(){puts("Hello World!");}char*C=".c
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4. Usage with currently available tools
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The sample program in listing 1 is 36 bytes long. By using the new
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compression method, the example program may be squeezed to sixteen
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bytes. In the example the compression ratio is 2:1. It is evident
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that the longer the program is, the better the compression ratio
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is. The maximum compression ratio in a UNIX environment is 254:16
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which equals approximately to 16:1. By using the method a one
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megabyte of source code can be compressed to 64 kilobytes.
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I have tested how well this new method works with currently
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available programming tools.
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One might easily think that the program could be compressed to a
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single byte by writing a one character long preprocessor directive
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in the source file and defining the actual source code in the
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command line, eg. 'cc hello.c -DX=main(){puts...'. With this
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method nothing is gained, since the compiling commands must be
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stored in a file, and that takes even more space than writing the
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code in a source file as presented in listing 1.
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Any ANSI conforming C-compiler that runs under a REAL operating
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system should be able to compile the code. (there may be problems
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with some older UNIX variants)
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4.1. Compilers:
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### Packing files in a UNIX environment
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In a UNIX environment it is possible to write almost any program by
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including the code in file names. Since '/' is used to separate
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path components and cannot therefore exist in a file name, all
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features of C-language cannot be used.
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In C, the `/` is used as a division operator and it may also be a
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part of a comment start and end identifier. This is, however, not a
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dangerous limitation, since practice has shown that comments are
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almost totally unnecessary. A real programmer can more easily
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understand pure source code, and misleading comments are
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disastrous. The division operation may be replaced with `pow(x, -1)`
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and multiplication when using real numbers or with `div()` function
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when using integers.
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Large programs must be separated into small modules. This enforces
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people to write better programs, since monolithic programming style
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cannot be used. Program development will also be faster, no extra
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code need not be recompiled after changes have been made.
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### Usage with currently available tools
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I have tested how well this new method works with currently
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available programming tools.
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Any ANSI conforming C-compiler that runs under a REAL operating
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system should be able to compile the code. (there may be problems
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with some older UNIX variants)
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### Compilers:
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These worked:
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These worked:
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gcc versions 2.0, 2.1, 2.3.2 (ld failed at AIX with gcc 2.1)
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cc (HP-UX)
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cc (VAX)
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These failed miserably:
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These failed miserably:
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cc (SunOs/Solaris) - could not start cpp properly
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cc/xlc (AIX) - could not open source
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4.2. Other tools:
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### Other tools:
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4.2.1 Debuggers: (tested at SunOs 4.1.2)
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#### Debuggers: (tested at SunOs 4.1.2)
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dbx - Quit with a very 'informative' error message:
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"dbx: fatal error: Is a directory"
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dbx - Quit with a very 'informative' error message:
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"dbx: fatal error: Is a directory"
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gdb - Printed almost the same error message ":Is a directory".
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It was, however, possible to step through the code but
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not list it.
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gdb - Printed almost the same error message ":Is a directory".
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It was, however, possible to step through the code but
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not list it.
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4.2.2 Lints:
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#### Lints
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- None of the lints at tested environments were able
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to open the file.
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None of the lints tested environments were able to parse the file.
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5. Conclusions
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### Conclusions
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The method can be used to compress any types of files, actually the
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compression ratios are even better when compressing other files
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than C-source. For example plain text files may be compressed with
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INFINITE compression ratio. It is trivial task to compress a 100
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kilobytes long text file in about 400 files whose lengths are zero
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bytes. The drawback is that the files must be unpacked before they
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can be used, so a large amount of temporary disk space is needed,
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while C-source is totally usable in the compressed form.
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The method can be used to compress any types of files, actually the
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compression ratios are even better when compressing other files
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than C-source. For example plain text files may be compressed with
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INFINITE compression ratio. It is trivial task to compress a 100
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kilobytes long text file in about 400 files whose lengths are zero
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bytes. The drawback is that the files must be unpacked before they
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can be used, so a large amount of temporary disk space is needed,
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while C-source is totally usable in the compressed form.
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Evidently, there is a long way to go before this new programming
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technique may be widely used, since currently there are only few
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tools supporting it. The advantages over the traditional methods
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are, however, so great that there is no doubt that this method will
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be new standard.
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Evidently, there is a long way to go before this new programming
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technique may be widely used, since currently there are only few
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tools supporting it. The advantages over the traditional methods
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are, however, so great that there is no doubt that this method will
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be new standard.
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## Copyright and CC BY-SA 4.0 License:
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Reference in new issue
Block a user