C Programming/Standard library reference

Headers Edit

ANSI C (C89)/ISO C (C90) Edit

assert.h Verify program assertion file
ctype.h Character types file.
errno.h System error numbers file
float.h Floating types file
limits.h Implementation-defined constants file.
locale.h Category macros file.
math.h Mathematical declarations file.
setjmp.h Stack environment declarations file.
signal.h Signals file.
stdarg.h Handle variable argument list file.
stddef.h Standard type definitions file.
stdio.h Standard buffered input/output file.
stdlib.h Standard library definitions file.
string.h String operations file.
time.h Time types file.

ISO C (C94/C95), Amendment 1 (AMD1) Edit

Very old compilers may not include some or all of these headers

iso646.h Alternative spellings.
wchar.h Wide-character handling.
wctype.h Wide-character classification and mapping utilities.

ISO C (C99) Edit

These are supported only in newer compilers

complex.h Complex arithmetic.
fenv.h Floating-point environment.
inttypes.h Fixed size integer types.
stdbool.h Boolean type and values.
stdint.h Integer types.
tgmath.h Type-generic macros.

ISO C (C11) Edit

These are supported only in newer compilers

stdalign.h Alignment keywords and macros.
stdatomic.h Atomic operations on data shared between threads.
stdnoreturn.h _Noreturn function specifier macro.
threads.h Support for multiple threads of execution.
uchar.h Types and functions for manipulating Unicode characters.

Table of functions Edit

This table also includes function-like macros

assert.h Edit

complex.h Edit

ctype.h Edit

fenv.h Edit

inttypes.h Edit

locale.h Edit

math.h Edit

setjmp.h Edit

signal.h Edit

stdarg.h Edit

stdatomic.h Edit

stddef.h Edit

stdio.h Edit

stdlib.h Edit

string.h Edit

threads.h Edit

time.h Edit

uchar.h Edit

wchar.h Edit

wctype.h Edit