List of C functions

The predefined functions used in the C standard library, and a few of the non-standard functions, include:

• assert.h

assert (macro)

• complex.h

cabs

cacos

cacosh

carg

Template:Dn

casinh

Template:Dn

catanh

ccos

ccosh

cexp

cimag

cis (non-standard)

Template:Dn

conj

cpow

cproj

creal

csin

csinh

csqrt

ctan

ctanh

• ctype.h

digittoint (non-standard)

isalnum

isalpha

isascii (non-standard)

isblank

iscntrl

isdigit

isgraph

islower

isprint

ispunct

isspace

isupper

isxdigit

toascii (non-standard)

tolower

toupper

• errno.h

(no functions)

• float.h

(no functions)

• inttypes.h

imaxabs

imaxdiv

strtoimax

strtoumax

wcstoimax

wcstoumax

• iso646.h

(no functions)

• limits.h

(no functions)

• locale.h

localeconv

setlocale

• math.h

acos

asin

atan

atan2

atof

ceil

cos

cosh

exp

fabs

floor

frexp

ldexp

log

log10

modf

pow

sin

sinh

sqrt

tan

tanh

• netdb.h

getaddrinfo

getnameinfo

• setjmp.h

longjmp, setjmp

• signal.h

raise

• stdarg.h

va_arg (macro)

va_copy (macro)

va_end (macro)

va_start (macro)

• stddef.h

offsetof (macro)

• stdio.h

clearerr

fclose

feof

ferror

fflush

fgetc

fgetpos

fgets

fopen, freopen, fdopen (non-standard)

fprintf

fputc

fputs

fread

fscanf

fseek

fsetpos

ftell

fwrite

getc (macro)

getchar (macro)

gets

perror

printf, fprintf, sprintf, snprintf (non-standard)

putc (macro)

putchar, fputchar (non-standard) (macro)

puts

remove

rename

rewind

scanf, fscanf, sscanf, vfscanf (non-standard), vscanf, vsscanf

setbuf

setvbuf

tmpfile

tmpnam

ungetc

vprintf, vfprintf, vsprintf

• stdlib.h

abort

abs, labs

atexit

atof

atoi

atol

bsearch

div, ldiv

exit

free

itoa (non-standard)

getenv

ldiv

ltoa (non-standard)

malloc, calloc, and realloc

qsort

rand

srand

strtod

strtol

strtoul

system

• string.h

memchr

memcmp

memcpy

memmove

memset

strcat, strncat

strchr

strcmp, strncmp

strcoll

strcpy, strncpy

strcspn

strerror

strlen

strpbrk

strrchr

strspn

strstr

strtok

strxfrm

• time.h

asctime

clock

ctime

difftime

gmtime

localtime

mktime

strftime

time

• wchar.h

btowc

fgetwc

fgetws

fputwc

fputws

fwide

fwprintf

fwscanf

getwc (macro)

getwchar (macro)

mbrlen

mbrtowc

mbsinit

mbsrtowcs

putwc (macro)

putwchar (macro)

swprintf

swscanf

ungetwc

vfwprintf

vswprintf

vwprintf

wcrtomb

wcscat

wcschr

wcscmp

wcscoll

wcscpy

wcscspn

wcsftime

wcslen

wcsncat

wcsncmp

wcsncpy

wcspbrk

wcsrchr

wcsrtombs

wcsspn

wcsstr

wcstod

wcstok

wcstol

wcstoul

wcsxfrm

wctob

wmemchr

wmemcmp

wmemcpy

wmemmove

wmemset

wprintf

wscanf

• wctype.h

iswalnum

iswalpha

iswcntrl

iswctype

iswdigit

iswgraph

iswlower

iswprint

iswpunct

iswspace

iswupper

iswxdigit

towctrans

towlower

towupper

wctrans

wctype

Non-standard headers

• alloc.h

farmalloc

• conio.h

getch, getche, gotoxy