SyntaxFix

Write A Post

Hire A Developer

Questions

Tags

[c] how to use #ifdef with an OR condition?

Sorry for asking very basic question. I would like to set OR condition in #ifdef directive.? How to do that ? I tried

#ifdef LINUX | ANDROID
...
..
#endif

It did not work? What is the proper way?

This question is related to c macros

The answer is

OR condition in #ifdef

#if defined LINUX || defined ANDROID
// your code here
#endif /* LINUX || ANDROID */

or-

#if defined(LINUX) || defined(ANDROID)
// your code here
#endif /* LINUX || ANDROID */

Both above are the same, which one you use simply depends on your taste.

P.S.: #ifdef is simply the short form of #if defined, however, does not support complex condition.

Further-

AND: #if defined LINUX && defined ANDROID
XOR: #if defined LINUX ^ defined ANDROID

Source: Stackoverflow.com

Examples related to c

• conflicting types for 'outchar' • Can't compile C program on a Mac after upgrade to Mojave • Program to find largest and second largest number in array • Prime numbers between 1 to 100 in C Programming Language • In c, in bool, true == 1 and false == 0? • How I can print to stderr in C? • Visual Studio Code includePath • "error: assignment to expression with array type error" when I assign a struct field (C) • Compiling an application for use in highly radioactive environments • How can you print multiple variables inside a string using printf?

Examples related to macros

• How to use __DATE__ and __TIME__ predefined macros in as two integers, then stringify? • how to use #ifdef with an OR condition? • What is ":-!!" in C code? • How to pass macro definition from "make" command line arguments (-D) to C source code? • __FILE__ macro shows full path • Where are the recorded macros stored in Notepad++? • How to identify platform/compiler from preprocessor macros? • What does "#pragma comment" mean? • C Macro definition to determine big endian or little endian machine? • How do I show the value of a #define at compile-time?