tinyxxd 1.3.0

Performance

• Let colors enabled and ASCII (as opposed to EBCDIC) be the "happy path" that the code is optimized for.
• Do not check hextype in multiple locations. Check it once in main and then call the right function.
• Refactor several if-expressions and switches.
• Mark several functions as inline.
• Use const for several of the function arguments and variables.
• Identify performance bottlenecks using Valgrind and kcachegrind.

Code quality

• Use implicit checks for NULL and 0. (thanks @oliverkwebb).
• Add missing (void) arguments (thanks @oliverkwebb).
• Output usage information without using snprintf (thanks @oliverkwebb).
• Introduce a fflush_or_die and a fflush_fseek_and_putc function.
• Use an enum for the terminal colors.
• Use setColor and clearColor instead of colorPrologue and colorEpilogue.
• Let the ignore variable be a bool instead of an int.
• Remove unused variables and function arguments.
• Let a few variables be local instead of global.
• Rename some functions.

Tooling

• Add a profile target to the Makefile.
• Add a benchmark script for Python 3 named bench.py that confirms that the performance is mostly IO-bound, and also outputs a couple of graphs by using gnuplot.
• Add GitHub action configuration for benchmarking, generating Markdown and graphs and committing the results to the main branch.
• Move the functionality of the release.sh script into the Makefile, and remove the script.
• Add support for fuzzing by running make fuzz, by using afl-gcc and afl-fuzz.