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21st Century C

Cover of 21st Century C by Ben Klemens Published by O'Reilly Media, Inc.
  1. 21st Century C
  2. SPECIAL OFFER: Upgrade this ebook with O’Reilly
  3. A Note Regarding Supplemental Files
  4. Preface
    1. C Is Punk Rock
    2. Q & A (Or, the Parameters of the Book)
    3. Standards: So Many to Choose From
      1. The POSIX Standard
    4. Some Logistics
      1. Conventions Used in This Book
      2. Using Code Examples
      3. Safari® Books Online
      4. How to Contact Us
      5. Acknowledgments
  5. I. The Environment
    1. 1. Set Yourself Up for Easy Compilation
      1. Use a Package Manager
      2. Compiling C with Windows
      3. Which Way to the Library?
      4. Using Makefiles
      5. Using Libraries from Source
      6. Using Libraries from Source (Even if Your Sysadmin Doesn’t Want You To)
      7. Compiling C Programs via Here Document
    2. 2. Debug, Test, Document
      1. Using a Debugger
      2. Using Valgrind to Check for Errors
      3. Unit Testing
      4. Interweaving Documentation
      5. Error Checking
    3. 3. Packaging Your Project
      1. The Shell
      2. Makefiles vs. Shell Scripts
      3. Packaging Your Code with Autotools
    4. 4. Version Control
      1. Changes via diff
      2. Git’s Objects
      3. Trees and Their Branches
      4. Remote Repositories
    5. 5. Playing Nice with Others
      1. The Process
      2. Python Host
  6. II. The Language
    1. 6. Your Pal the Pointer
      1. Automatic, Static, and Manual Memory
      2. Persistent State Variables
      3. Pointers Without malloc
    2. 7. C Syntax You Can Ignore
      1. Don’t Bother Explicitly Returning from main
      2. Let Declarations Flow
      3. Cast Less
      4. Enums and Strings
      5. Labels, gotos, switches, and breaks
      6. Deprecate Float
    3. 8. Obstacles and Opportunity
      1. Cultivate Robust and Flourishing Macros
      2. Linkage with static and extern
      3. The const Keyword
    4. 9. Text
      1. Making String Handling Less Painful with asprintf
      2. A Pæan to strtok
      3. Unicode
    5. 10. Better Structures
      1. Compound Literals
      2. Variadic Macros
      3. Safely Terminated Lists
      4. Foreach
      5. Vectorize a Function
      6. Designated Initializers
      7. Initialize Arrays and Structs with Zeros
      8. Typedefs Save the Day
      9. Return Multiple Items from a Function
      10. Flexible Function Inputs
      11. The Void Pointer and the Structures It Points To
    6. 11. Object-Oriented Programming in C
      1. What You Don’t Get (and Why You Won’t Miss It)
      2. Extending Structures and Dictionaries
      3. Functions in Your Structs
      4. Count References
    7. 12. Libraries
      1. GLib
      2. POSIX
      3. The GNU Scientific Library
      4. SQLite
      5. libxml and cURL
  7. Epilogue
  8. Glossary
  9. Bibliography
  10. Index
  11. About the Author
  12. Colophon
  13. SPECIAL OFFER: Upgrade this ebook with O’Reilly
  14. Copyright

Chapter 8. Obstacles and Opportunity

There’s no C Foundation paying me to advocate the language, and this book is not a sales pitch dressed up as a tutorial, so I can write freely about C’s problems. The bits here are too valuable to be in the don’t-bother category under which so many of the items in the previous chapter fall, but they also come with cautions about the historic cruft that made sense at the time and is now just a mess.

  • C’s macro facilities are pretty simple but still pack in a lot of little exceptions.

  • The usage of the static keyword is at this point painfully confusing, though in the end, it will give us a nice alternative to elaborate macros. Its complement in certain senses, the extern keyword, also gives us enough rope with which to hang ourselves.

  • The const keyword fits this chapter because it is too useful to not use, but it has oddities in its specification in the standard and in its implementation in common compilers.

Cultivate Robust and Flourishing Macros

Chapter 10 will present several options for making the user interface to your library friendlier and less error-inviting, and will rely heavily on macros to do it.

I read a lot of people who say that macros are themselves invitations for errors and should be avoided, but those people don’t advise that you shouldn’t use NULL, isalpha, isfinite, assert, type-generic math like log, sin, cos, pow, and so on, or any of the dozens of other facilities defined by the GNU standard library via macros. Those are well-written, ...

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