Defined in header <math.h> float log1pf( float arg ); (1) (since C99) double log1p( double arg ); (2) (since C99) long double log1pl( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define log1p( arg ) (4) (since C99) 1-3) Computes the natural (base e) logarithm of 1+arg. This function is more precise than the expression log(1+arg) if arg is close to zero. 4) Type-generic macro: If arg has type long double, log1pl

If the macro constant __STDC_NO_COMPLEX__ is defined by the implementation, the complex types, the header <complex.h> and all of the names listed here are not provided. (since C11) The C programming language, as of C99, supports complex number math with the three built-in types double _Complex, float _Complex, and long double _Complex (see _Complex). When the header <complex.h> is included, the three complex number types are also accessible as double complex, float complex, long

Defined in header <stdio.h> int feof( FILE *stream ); Checks if the end of the given file stream has been reached. Parameters stream - the file stream to check Return value nonzero value if the end of the stream has been reached, otherwise ​0​ Notes This function only reports the stream state as reported by the most recent I/O operation, it does not examine the associated data source. For example, if the most recent I/O was a fgetc, which returned the last

Defined in header <uchar.h> size_t c16rtomb( char* s, char16_t c16, mbstate_t* ps ); (since C11) Converts a 16-bit wide character to narrow multibyte character. If s is not a null pointer, the function determines the number of bytes necessary to store the multibyte character representation of c16 (including any shift sequences), and stores the multibyte character representation in the character array whose first element is pointed to by s. At most MB_CUR_MAX bytes can be wr

Defined in header <wchar.h> (1) wchar_t* wcsncpy( wchar_t* dest, const wchar_t* src, size_t count ); (since C95) (until C99) wchar_t *wcsncpy(wchar_t *restrict dest, const wchar_t *restrict src, size_t n); (since C99) errno_t wcsncpy_s( wchar_t *restrict dest, rsize_t destsz, const wchar_t *restrict src, rsize_t n); (2) (since C11) 1) Copies at most count characters of the wide string pointed to by src (including the terminating null wide cha

Defined in header <time.h> size_t strftime( char * str, size_t count, const char * format, const struct tm * time ); (until C99) size_t strftime( char *restrict str, size_t count, const char *restrict format, const struct tm *restrict time ); (since C99) Converts the date and time information from a given calendar time time to a null-terminated multibyte character string str according to format string format.

Defined in header <math.h> #define isinf(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg is positive or negative infinity. 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 - floating point value Return value Nonzero integ

Defined in header <signal.h> #define SIG_ERR /* implementation defined */ A value of type void (*)(int). When returned by signal, indicates that an error has occurred. Example #include <stdio.h> #include <stdlib.h> #include <signal.h> void signal_handler(int signal) { printf("Received signal %d\n", signal); } int main(void) { /* Install a signal handler. */ if (signal(SIGTERM, signal_handler) == SIG_ERR) { printf("Error whi

Defined in header <ctype.h> int ispunct( int ch ); Checks if the given character is a punctuation character in the current C locale. The default C locale classifies the characters !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~ as punctuation. The behavior is undefined if the value of ch is not representable as unsigned char and is not equal to EOF. Parameters ch - character to classify Return value Non-zero value if the character is a punctuation character, zero o

Defined in header <setjmp.h> void longjmp( jmp_buf env, int status ); (until C11) _Noreturn void longjmp( jmp_buf env, int status ); (since C11) Loads the execution context env saved by a previous call to setjmp. This function does not return. Control is transferred to the call site of the macro setjmp that set up env. That setjmp then returns the value, passed as the status. If the function that called setjmp has exited (whether by return or by a different longjmp hi