C Recipes: Code & SQL

Runnable C + SQL cheat sheet

Free · In-App Purchases

In C, undefined behavior compiles cleanly and can even seem to work. Here the examples run for real, and comments flag classic traps like overflow and leaks. Tap Run and the real output appears right under the code, so you know what it does before it goes into your project. No compiler, no IDE, no setup, no account. 270+ short examples in C23, one task each. Over 95% compile with GCC on Linux and run in the app with one tap. You know what you need, but not the exact syntax: • How do I join strings without writing past the end of the buffer? • How do I grow an array with realloc and not leak it on failure? • How do I add two ints and find out if the sum overflowed? Each has a working example here. • 20 sections, including pointers and memory, structs, bit fields and masks, the preprocessor, errno and return codes, C11 threads, files, and design patterns. • What changed from C89 to C23, with before-and-after code: designated initializers, _Generic, _Static_assert, nullptr. • Keyword and library reference, 240+ entries: tap a word in the code to look it up. • 200+ SQL queries: JOIN, GROUP BY, subqueries, window functions; more than half run on a practice database. • Search looks inside the code: type memcpy to find every example that uses it. • Edit an example and run your version, or write your own. • Works on iPhone, iPad, and Mac. • Everything except running code works offline. Free version: 160+ C examples and 120+ SQL queries, the full reference, and 12 runs and 12 edits a day (C and SQL runs share one count). Full version: all examples and queries, unlimited edits and examples of your own, and up to 30 C and 80 SQL runs a day. One-time purchase, no subscription. Built by a developer for developers. The project behind it has been in active development since 2015.

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    Information

    Provider
    Fedor Obraztsov
    Size
    6.8 MB
    Category
    Developer Tools
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later.
    Languages
    English and 14 more
    • English, Arabic, French, German, Hebrew, Indonesian, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Turkish, Vietnamese
    Age Rating
    4+
    In-App Purchases
    Yes
    Copyright
    © Fedor Obraztsov
  • Developer Website
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