Author:

• Name: Thomas P John
  Location: NL - Kingdom of the Netherlands (Netherlands)

To build:

    make

There is an alternate version that compiles mkentry.c. See Alternate code.

To use:

    ./tomx

Try:

    ./try.sh

Alternate code:

This alternate code is based on the author’s remarks with a slight fix so that it will do what it once did, compile and run mkentry.c. You can use it in a similar way as tomx.c, both executing the source file and using it as a Makefile and running the code ends up running mkentry.

Alternate build:

    make alt

Alternate try:

    ./try.alt.sh

Judges’ remarks:

Polyglots have come and gone, but this was the first one we’d seen where one language used another to perform its tasks. An interesting approach. Admittedly, it’s not all that obfuscated - but there’s more to it than you might think, since you have to make sure that your changes don’t change the shell code or the Makefile.

Author’s remarks:

Summary

This program works as a C source file, a Makefile and also as a shell (/bin/sh) script. But unlike some other multi-language programs, this one is NOT meant to print Hello, world in all 3 cases (At least in the true sense ;-)). The C, Makefile and shell code build upon each other to create a C program (?) which when executed as a shell script will compile itself through the C compiler using a Makefile! - Pretty useful, Eh?

Probably, this is the first entry ever to fully satisfy Rule #1 (“Your entry must be a complete program”) in the strictest sense;-)

Top 5 reasons (IMHO) why this code is an entry for IOCCC

1. A glance at the source itself will tell you that most of the Obfuscation is NOT in the C code per se, but in the comments to the C code. (But sadly, I could not find an “International Obfuscated C COMMENT contest”. So I HAD to send this entry here to the IOCCC itself).

2. Of the 3 languages in the source, the least obfuscated is C (But again, there was NO obfuscated make/shscript contest) (Does this hint for a rule in IOCCC-2001 that the major obfuscation should be in C and not elsewhere???. Mmmmm…).

3. Extending Argument #2… Obfuscation done in the C code (comments?) creates obfuscated code for the other 2 languages. This opens new possibilities to be explored in depth in future IOCCCs.

4. LOOKS like a Makefile, WORKS like a shell script and COMPILES like a C program.

5. Does something useful (See Notes #1 and #2 below).

Notes

1. The program could have been something other than the simple “Hello, world” program that it is. It is possible to do #include "prog2.c" in the place of the main(), leaving the complexities of the C file elsewhere and making this source still acceptable to make and sh. The following modification to the last few lines will compile the IOCCC’s famous mkentry.c.

    .PHONY: /* true clean */
    #undef   true
    #include "mkentry.c"

Ain’t that useful?

2. By extending this program’s idea, It is possible to do some very interesting things like generating C code on execution by adding additional code in make/sh (open up a loop????). This opens the possibilities of generating & compiling some (obfuscated?) C code. (Maybe should try this if this program fails at IOCCC 2000)

3. Changing the %:%.c dependency to a $(PROG):$(PROG).c form can compile this program with some other makes (I got it to work in Windows using nmake and Gnuwin32’s sh ;-) )

4. Interesting things to do: try ./tomx.c clean. This will do the same as make clean :-)). Also: ./tomx.c all

5. Be careful about the tabs in the source code. Removing them or converting tabs to spaces can be disastrous.

Primary files

• tomx.c - entry source code
• Makefile - entry Makefile
• tomx.alt.c - alternate source code
• tomx.orig.c - original source code
• try.alt.sh - script to try alternate code
• try.sh - script to try entry
• mkentry.c - IOCCC mkentry source code from 1998

Secondary files

• 2000_tomx.tar.bz2 - download entry tarball
• README.md - markdown source for this web page
• .entry.json - entry summary and manifest in JSON
• .gitignore - list of files that should not be committed under git
• .path - directory path from top level directory
• index.html - this web page

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