Defined in header <locale.h> lconv* localeconv(); The localeconv function obtains a pointer to a static object of type lconv, which represents numeric and monetary formatting rules of the current C locale. Parameters (none). Return value pointer to the current lconv object. Notes Modifying the object references through the returned pointer is undefined behavior. localeconv modifies a static object, calling it from different threads without synchronization is undefi

Defined in header <signal.h> #define SIG_DFL /*implementation defined*/ #define SIG_IGN /*implementation defined*/ The SIG_DFL and SIG_IGN macros expand into integral expressions that are not equal to an address of any function. The macros define signal handling strategies for signal() function. Constant Explanation SIG_DFL default signal handling SIG_IGN signal is ignored Example #include <signal.h> #include <stdio.h> int main(void) {

Defined in header <stdlib.h> void _Exit( int exit_code ); (since C99) Causes normal program termination to occur without completely cleaning the resources. Destructors of variables with automatic, thread local and static storage durations are not called. Functions passed to at_quick_exit() or atexit() are not called. Whether open resources such as files are closed is implementation defined. If exit_code is EXIT_FAILURE, an implementation-defined status, indicating unsuccess

Defined in header <stdlib.h> int at_quick_exit( void (*func)() ); (since C11) Registers the function pointed to by func to be called on quick program termination (via quick_exit). Calling the function from several threads does not induce a data race. The implementation shall support the registration of at least 32 functions. Parameters func - pointer to a function to be called on normal program termination Return value ​0​ if the registration succeeds, nonzero

Defined in header <signal.h> #define SIGTERM /*implementation defined*/ #define SIGSEGV /*implementation defined*/ #define SIGINT /*implementation defined*/ #define SIGILL /*implementation defined*/ #define SIGABRT /*implementation defined*/ #define SIGFPE /*implementation defined*/ Each of the above macro constants expands to an integer constant expression with distinct values, which represent different signals sent to the program. Constant

Defined in header <threads.h> void cnd_destroy( cnd_t* cond ); (since C11) Destroys the condition variable pointed to by cond. If there are threads waiting on cond, the behavior is undefined. Parameters cond - pointer to the condition variable to destroy Return value (none). References C11 standard (ISO/IEC 9899:2011): 7.26.3.2 The cnd_destroy function (p: 378-379)

Defined in header <assert.h> #define static_assert _Static_assert This convenience macro expands to the keyword _Static_assert. Example #include <assert.h> int main(void) { static_assert(2 + 2 == 4, "2+2 isn't 4"); // well-formed static_assert(sizeof(int) < sizeof(char), "this program requires that int is less than char"); // compile-time error } References C11 standard (ISO/IEC 9899:2011): 7.2/3 Diagnostics <assert.h>

Defined in header <stdio.h> int fputc( int ch, FILE *stream ); int putc( int ch, FILE *stream ); Writes a character ch to the given output stream stream. putc() may be implemented as a macro and evaluation stream more than once, so the corresponding argument should never be an expression with side effects. Internally, the character is converted to unsigned char just before being written. Parameters ch - character to be written stream - output stream

Defined in header <math.h> #define signbit(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg is negative. The macro returns an integral value. Parameters arg - floating point value Return value Nonzero integral value if arg is negative, ​0​ otherwise. Notes This macro detects the sign bit of zeroes, infinities, and NaNs. Along with copysign, this macro is one of the only two portable ways to examine the sign of

Defined in header <math.h> #define isfinite(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg has finite value i.e. it is normal, subnormal or zero, but not infinite or NaN. The macro returns an integral value. FLT_EVAL_METHOD is ignored: even if the argument is evaluated with more range and precision than its type, it is first converted to its semantic type, and the classification is based on that. Parameters arg - floa