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

Usage sizeof operator

Each of the macros defined in <errno.h> expands to an integer constant expression with type int and with a unique positive value. The following constants are defined (the implementation may define more, as long as they begin with 'E' followed by digits or uppercase letters). Defined in header <errno.h> EDOM Mathematics argument out of domain of function (macro constant) EILSEQ (C95) Illegal byte sequence (macro constant) ERANGE Result too large (macro constant)

Defined in header <wchar.h> (1) wchar_t *wcscpy( wchar_t *dest, const wchar_t *src ); (since C95) (until C99) wchar_t *wcscpy( wchar_t *restrict dest, const wchar_t *restrict src ); (since C99) errno_t wcscpy_s( wchar_t *restrict dest, rsize_t destsz, const wchar_t *restrict src ); (2) (since C11) 1) Copies the wide string pointed to by src (including the terminating null wide character) to wide character array pointed to by dest. The behavior

Defined in header <math.h> float lgammaf( float arg ); (1) (since C99) double lgamma( double arg ); (2) (since C99) long double lgammal( long double arg ); (3) (since C99) Defined in header <tgmath.h> #define lgamma( arg ) (4) (since C99) 1-3) Computes the natural logarithm of the absolute value of the gamma function of arg. 4) Type-generic macro: If arg has type long double, lgammal is called. Otherwise, if arg has integer type o

Defined in header <complex.h> float complex ctanhf( float complex z ); (1) (since C99) double complex ctanh( double complex z ); (2) (since C99) long double complex ctanhl( long double complex z ); (3) (since C99) Defined in header <tgmath.h> #define tanh( z ) (4) (since C99) 1-3) Computes the complex hyperbolic tangent of z. 4) Type-generic macro: If z has type long double complex, ctanhl is called. if z has type double complex,

Defined in header <string.h> int strcoll( const char *lhs, const char *rhs ); Compares two null-terminated byte strings according to the current locale as defined by the LC_COLLATE category. Parameters lhs, rhs - pointers to the null-terminated byte strings to compare Return value Negative value if lhs is less than (precedes) rhs. ​0​ if lhs is equal to rhs. Positive value if lhs is greater than (follows) rhs. Notes Collation order is the dictionary order:

Transfers control unconditionally to the desired location. Used when it is otherwise impossible to transfer control to the desired location using conventional constructs. Syntax goto label ; label : statement Explanation The goto statement causes an unconditional jump (transfer of control) to the statement prefixed by the named label (which must appear in the same function as the goto statement), except when this jump would enter the scope of a variable-length array or anoth

Defined in header <stdlib.h> void abort_handler_s( const char * restrict msg, void * restrict ptr, errno_t error ); (since C11) Writes an implementation-defined message to stderr which must include the string pointed to by msg and calls abort(). A pointer to this function can be passed to set_constraint_handler_s to establish a runtime constraints violation handler. As with all bounds-checked functions, abort_

Defined in header <math.h> #define isnan(arg) /* implementation defined */ (since C99) Determines if the given floating point number arg is a not-a-number (NaN) value. 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 (this matters if the evaluation type supports NaNs, while the semantic type does n