Defined in header <math.h> float atanf( float arg ); (1) (since C99) double atan( double arg ); (2) long double atanl( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define atan( arg ) (4) (since C99) 1-3) Computes the principal value of the arc tangent of arg. 4) Type-generic macro: If the argument has type long double, atanl is called. Otherwise, if the argument has integer type or the type double, atan is call

Defined in header <time.h> struct tm *gmtime( const time_t *time ); (1) struct tm *gmtime_s(const time_t *restrict time, struct tm *restrict result); (2) (since C11) 1) Converts given time since epoch (a time_t value pointed to by time) into calendar time, expressed in Coordinated Universal Time (UTC) in the struct tm format. The result is stored in static storage and a pointer to that static storage is returned. 2) Same as (1), except that the function uses user-pr

Defined in header <math.h> float modff( float arg, float* iptr ); (1) (since C99) double modf( double arg, double* iptr ); (2) long double modfl( long double arg, long double* iptr ); (3) (since C99) 1-3) Decomposes given floating point value arg into integral and fractional parts, each having the same type and sign as arg. The integral part (in floating-point format) is stored in the object pointed to by iptr. Parameters arg - floating point

Defined in header <wctype.h> int iswprint( wint_t ch ); (since C95) Checks if the given wide character can be printed, i.e. it is either a number (0123456789), an uppercase letter (ABCDEFGHIJKLMNOPQRSTUVWXYZ), a lowercase letter (abcdefghijklmnopqrstuvwxyz), a punctuation character(!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~), space or any printable character specific to the current C locale. Parameters ch - wide character Return value Non-zero value if the wid

Defined in header <wchar.h> (1) wchar_t* wmemcpy( wchar_t* dest, const wchar_t* src, size_t count ); (since C95) (until C99) wchar_t *wmemcpy(wchar_t *restrict dest, const wchar_t *restrict src, size_t count ); (since C99) errno_t wmemcpy_s( wchar_t *restrict dest, rsize_t destsz, const wchar_t *restrict src, rsize_t count ); (2) (since C11) 1) Copies exactly count successive wide characters from the wide character array poin

Usage inline function specifier

Comparison operators are binary operators that test a condition and return 1 if that condition is logically true and 0 if that condition is false.. Operator Operator name Example Description == equal to a == b a is equal to b != not equal to a != b a is not equal to b < less than a < b a is less than b > greater than a > b a is greater than b <= less than or equal to a <= b a is less than or equal to b >= greater than or eq

Defined in header <stdlib.h> unsigned long strtoul( const char *str, char **str_end, int base ); (until C99) unsigned long strtoul( const char *restrict str, char **restrict str_end, int base ); (since C99) unsigned long long strtoull( const char *restrict str, char **restrict str_end, int base ); (since C99) Interprets an unsigned integer value in

Usage restrict type qualifier

Defined in header <ctype.h> int isdigit( int ch ); Checks if the given character is a numeric character (0123456789). 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 numeric character, zero otherwise. Notes isdigit and isxdigit are the only standard narrow character classification functions that are not affected