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

Usage inline function specifier

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

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 <stdio.h> size_t fread( void *buffer, size_t size, size_t count, FILE *stream ); (until C99) size_t fread( void *restrict buffer, size_t size, size_t count, FILE *restrict stream ); (since C99) Reads up to count objects into the array buffer from the given input stream stream as if by calling fgetc size times for each object, and storing the results, in the order obtained, into the successive positions o

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

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