Dear C Developers,

I’ve spent a good amount of time integrating various C codebases into production-ready software. It’s an interesting challenge, but I often face a few common pain points during the initial stages. Here are some tips that I believe will save us all a lot of time and headaches.

Improve Your Logs

Many C developers still rely on basic fprintf(stderr, ...) for logging errors. Consider using a more sophisticated logging approach, such as this one. At a minimum, include __FILE__ and __LINE__ macros to make debugging easier for everyone.

Use Compiler Warnings

When using gcc, always enable -Wall -Werror (and -Wextra if possible). These warnings will catch many potential bugs early on and save a lot of troubleshooting time.

Standardize Error Codes

Avoid reinventing the wheel for error codes. Use the POSIX error codes to make your code more readable and consistent.

Handle Errors and Log Them Properly

Always check return codes and log abnormal cases. Here’s an example of what not to do:

FILE *f = fopen("logs.txt", "w");
if (!f)
   goto end;

Instead, use proper logging:

LL_WARNING("Could not open log file!");

You can find an example of this kind of macro here.

Avoid “Magic Numbers”

Wherever possible, replace magic numbers with sizeof(). It makes the code more readable and reduces the mental load for others who are trying to understand (or fix) it.

Leverage POSIX Standard Headers and Libraries

Make use of the many available standard libraries and headers. For example, stdbool.h is now standard—use it! For argument parsing, use standard functions instead of crafting your own.

Great Non-Standard Libraries

Libraries like json-c for serialization and zeromq for networking can save you a lot of time and effort.

Be Careful with Memory Management

Memory leaks and buffer overflows can happen. Tools like valgrind can help catch these problems early. Remember that memory behavior varies between OS and architectures—a bug that doesn’t appear on your desktop might show up on an embedded ARM device.

Avoid Overusing malloc

In many cases, stack allocation is sufficient and much safer. C99 allows flexible array declarations, such as:

uint8_t bin[strlen(hex)/2+1];

Use a Debugger

Debuggers are your best friends. Tools integrated into IDEs like NetBeans or CLion can save you hours by giving you instant insights into why your code crashed or stalled. Also, if you’re facing mysterious crashes, try compiling with -fstack-protector to detect stack smashing issues earlier.

Optimization

Let the compiler do its job. Avoid manual optimizations like inline or prefetching unless you are absolutely sure about their impact. Trust the compiler’s optimization capabilities.

Avoid Custom Network Protocols

Stick to readable protocols like JSON over zeromq. They’re easier to debug, monitor, and maintain compared to custom binary formats.

Learn Other Languages

Sometimes, C isn’t the best tool for the job. For scripting or rapid development, consider using Python, Go, or Node.js. You’ll often gain a massive productivity boost, and for many use cases, the slight performance hit is negligible.

Write Maintainable Makefiles

Use tools like autoconf, automake, or write simple Makefiles that are easy to maintain, such as this one.

IDEs Are Worth It

Take the time to learn a good IDE like NetBeans, CLion, or even Vim. A good setup can significantly speed up your development process.

These best practices can make a huge difference in how easily your code can be integrated, maintained, and extended. Let’s make our lives — and those of our fellow developers — easier by adhering to these simple guidelines.