Author:

• Name: J. David Lowe
  Location: US - United States of America (United States)

To build:

    make

Bugs and (Mis)features:

The current status of this entry is:

STATUS: INABIAF - please DO NOT fix

For more detailed information see 2013/dlowe in bugs.html.

To use:

    ./dlowe [number...]

where [number...] is one or more number, space separated.

Try:

    ./try.sh

What is different about the above if you do something like:

    echo 'IOCCC winning entry 2013/dlowe' > ioccc.txt
    ./try.sh
    rm -f ioccc.txt

?

To make it simpler to see try showing just the different line like:

    ./diff.sh

Judges’ remarks:

We liked how this entry used Unicode, specifically UTF-8, in a somewhat obfuscated way.

Also, why doesn’t it crash but instead produces a correct output when called with one argument or when all arguments are equal?

For extra fun, compile and run fun.c:

    #include <stdio.h>
    int main() {
        printf("%d %d %d\n", (int)(-1.0/0.0), (int)(0.0/0.0), (int)(1.0/0.0));
    }

with gcc and clang.

With GCC (4.7.2), we get

    -2147483648 -2147483648 -2147483648

and with clang (3.3), we get

    -2147483648 0 2147483647

and with Apple clang version 15.0.0 (clang-1500.0.40.1) in 2023, we get:

    1840985120 -2033041452 35979112

Which one is correct? :)

NOTE: make all will compile fun.c but to provide a different compiler you can do something like:

    make CC=clang fun

Author’s remarks:

sparkl

A tiny implementation of command-line sparkline data visualization.

Synopsis

    $ ./sparkl 0 1 2 3 4 5 6 7
    ▁▂▃▄▅▆▇▉

    $ echo "sparkline of file lengths: $(wc -c * | awk '{print $1}' | xargs ./sparkl)"
    sparkline of file sizes: ▁▁▁▃▃▂▁▂▁▁▉

NOTE: this has been provided in slflen.sh so you can try:

    ./slflen.sh

instead (which try.sh also uses).

Description

This is a handy little tool for visualizing numeric series from the command line, using sparklines. Pass it a numeric series as arguments, and sparkl will display a sparkline graph, which you can use to very quickly get a sense of the shape of your data.

Limitations

• Crashes with 0 arguments. It’d be trivial to fix, but adds a few bytes to the code.
• Produces bogus graphs when given > about 5000 arguments.
• Only works if your terminal is UTF-8 and your font supports the 8 glyphs used.
• Produces a few harmless compiler warnings.

Obfuscation

The code is very terse. I was torn between submitting this version, and a one-line version compressed using a couple more -D flags.

Hand-rolled UTF-8 sequence, magic numbers (what’s that 7 for?), meaningless variable names, reused variables, and so on.

Acknowledgements

Edward Tufte invented sparklines (among other things.) Brilliant.

Zach Holman’s ‘spark’ utility was absolutely an inspiration.

As I was writing up this description, I discovered I’m not the first person to write an obfuscated C sparkline utility! Vicent Martí created this one years (!) ago. (My implementation is completely independent.)

Primary files

• dlowe.c - entry source code
• Makefile - entry Makefile
• dlowe.orig.c - original source code
• diff.sh - difference tool
• fun.c - compile and run for extra fun
• slflen.sh - show sparkline length of all files in current directory
• try.sh - script to try entry

Secondary files

• 2013_dlowe.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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