https://en.wikipedia.org/wiki/C_standard_library +++Date last modified: 1997-07-05 Standard C functions defined by ANSI (ISO/IEC 9899:1990) abort() abs() acos() asctime() asin() assert() atan() atan2() atexit() atof() atoi() atol() bsearch() calloc() ceil() clearerr() clock() cos() cosh() ctime() difftime() div() exit() exp() fabs() fclose() feof() ferror() fflush() fgetc() fgetpos() fgets() floor() fmod() fopen() fprintf() fputc() fputs() fread() free() freopen() frexp() fscanf() fseek() fsetpos() ftell() fwrite() getc() getchar() getenv() gets() gmtime() isalnum() isalpha() iscntrl() isdigit() isgraph() islower() isprint() ispunct() isspace() isupper() isxdigit() labs() ldexp() ldiv() localeconv() localtime() log() log10() longjmp() malloc() mblen() mbstowcs() mbtowc() memchr() memcmp() memcpy() memmove() memset() mktime() modf() perror() pow() printf() putc() putchar() puts() qsort() raise() rand() realloc() remove() rename() rewind() scanf() setbuf() setjmp() setlocale() setvbuf() signal() sin() sinh() sprintf() sqrt() srand() sscanf() strcat() strchr() strcmp() strcoll() strcpy() strcspn() strerror() strftime() strlen() strncat() strncmp() strncpy() strpbrk() strrchr() strspn() strstr() strtod() strtok() strtol() strtoul() strxfrm() system() tan() tanh() time() tmpfile() tmpnam() tolower() toupper() ungetc() va_arg() va_end() va_start() vfprintf() vprintf() vsprintf() wcstombs() wctomb() Additional C numeric functions defined by NCEG feclearexcepts() fegetenv() fegetexcept() fegetprec() fegetround() feprocentry() feprocexit() feraiseexcept() fesetenv() fesetexcept() fesetprec() fesetround() fetestexcept() Additional C functions defined by Posix.1 access() alarm() cfgetispeed() cfgetospeed() cfsetispeed() cfsetospeed() chdir() chmod() chown() close() closedir() creat() ctermid() cuserid() dup() dup2() execl() execle() execlp() execv() execve() execvp() _exit() fcntl() fdopen() fileno() fork() fpathconf() fstat() getcwd() getegid() geteuid() getgid() getgrgid() getgrnam() getgroups() getlogin() getpgrp() getpid() getppid() getpwnam() getpwuid() getuid() kill() link() lseek() mkdir() mkfifo() open() opendir() pause() pipe() read() readdir() rewinddir() rmdir() setgid() setpgid() setsid() setuid() sigaction() sigaddset() sigemptyset() sigfillset() sigismember() siglongjmp() sigpending() sigprocmask() sigsetjmp() sigsuspend() sleep() stat() sysconf() tcdrain() tcflow() tcflush() tcgetattr() tcgetpgrp() tcsendbreak() tcsetattr() tcsetpgrp() times() ttyname() tzset() umask() uname() unlink() utime() wait() waitpid() write() Standard functions added by the draft C++ standard terminate() unexpected() Standard C keywords and operators defined by ANSI (ISO/IEC 9899:1990) ! != % %= & && &= () * *= + ++ += , - -- -= -> . / /= < << <<= > >> >>= ?: [] ^ ^= | |= || ~ auto break case char const continue default do double else enum extern float for goto if int long register return short signed sizeof static struct switch typedef union unsigned void volatile while Standard C preprocessor instructions defined by ANSI (ISO/IEC 9899:1990) # ## #define #elif #else #endif #error #if #if ! defined #if defined #ifdef #ifndef #include #line #pragma #undef __DATE__ __FILE__ __LINE__ __STDC__ __TIME__ Standard C trigraph sequences defined by ANSI (ISO/IEC 9899:1990) ??= means # ??( means [ ??/ means \ ??) means ] ??' means ^ ??< means { ??! means | ??> means } ??- means ~ Standard ANSI C character constant escape sequences \a Alert ASCII BEL (Ctrl-G) \b Backspace ASCII BS (Ctrl-H) \f Form feed ASCII FF (Ctrl-L) \n New line ASCII NL (Ctrl-J) \r Carriage return ASCII CR (Ctrl-M) \t Horizontal tab ASCII TAB (Ctrl-I) \v Vertical tab ASCII VT (Ctrl-K) \\ Literal backslash \' Literal apostrophe \" Literal quotation mark \? Literal Question mark \<1-3 octal digits> Char value in octal \x<1-2 hex digits> Char value in hex Standard keywords and operators added by the draft C++ standard ->* .* :: asm catch class delete delete[] friend inline new operator private protected public template this throw try virtual Standard C macros defined by ANSI (ISO/IEC 9899:1990) BUFSIZ CHAR_BIT CHAR_MAX CHAR_MIN CLOCKS_PER_SEC DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX DBL_MAX_10_EXP DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP DBL_MIN_EXP EDOM EOF ERANGE EXIT_FAILURE EXIT_SUCCESS FILENAME_MAX FLT_DIG FLT_EPSILON FLT_MANT_DIG FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP FLT_MIN FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS FOPEN_MAX HUGE_VAL INT_MAX INT_MIN _IOFBF _IOLBF _IONBF L_tmpnam LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP LONG_MAX LONG_MIN MB_CUR_MAX MB_LEN_MAX NDEBUG NULL RAND_MAX SCHAR_MAX SCHAR_MIN SEEK_CUR SEEK_END SEEK_SET SHRT_MAX SHRT_MIN SIG_DFL SIG_ERR SIG_IGN SIBGABRT SIGFPE SIGILL SIGINT SIGSEGV SIGTERM TMP_MAX UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX offsetof() Additional C numeric macros defined by NCEG FE_ALL_EXCEPT FE_DBLPREC FE_DIVBYZERO FE_DOWNWARD FE_FLTPREC FE_INEXACT FE_INVALID FE_LDBLPREC FE_OVERFLOW FE_TONEAREST FE_TOWARDZERO FE_UNDERFLOW FE_UPWARD fpclassify() FP_INFINITE FP_NANQ FP_NANS FP_NORMAL FP_SUBNORMAL FP_ZERO INFINITY isfinite() isnan() isnormal() NAN NANS __FPCE_IEEE__ __FPCE__ Additional C macros defined in Posix.1 ARG_MAX B0 B50 B75 B110 B134 B150 B200 B300 B600 B1200 B1800 B2400 B4800 B9600 B19200 B38400 BRKINT CHILD_MAX CLK_TCK CLOCAL CREAD CS5 CS6 CS7 CS8 CSIZE CSTOPB E2BIG EACCESS EAGAIN EBADF EBUSY ECHILD ECHO ECHOE ECHOK ECHONL EDEADLK EEXIST EFAULT EFBIG EINTR EINVAL EIO EISDIR EMFILE EMLINK ENAMETOOLONG ENFILE ENODEV ENOENT ENOEXEC ENOLCK ENOMEM ENOSPC ENOTDIR ENOTEMPTY ENOTTY ENXIO EPERM EPIPE EROFS ESPIPE ESRCH EXDEV FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK F_RDLCK F_SETFD F_SETFL F_SETLK F_SETLKW F_UNLCK F_WRLCK HUPCL ICANON ICRNL IEXTEN IGNBRK IGNCR IGNPAR IGNLCR INPCK ISIG ISTRIP IXOFF IXON LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP LINK_MAX L_ctermid MAX_CANON MAX_INPUT NAME_MAX NCCS NGROUPS_MAX NOFLSH OPEN_MAX OPOST O_ACCMODE O_APPEND O_CREAT O_EXCL O_NOCTTY O_NONBLOCK O_RDONLY O_RDWR O_TRUNC O_WRONLY PARENB PARMRK PARODD PATH_MAX PIPE_BUF R_OK SA_NOCLDSTOP SIGARLM SIGCHLD SIGCONT SIGHUP SIGKILL SIGPIPE SIGQUIT SIGSTOP SIGTSTP SIGTTIN SIGTTOU SIGUSR1 SIGUSR2 SIG_BLOCK SIG_SETMASK SIG_UNBLOCK SSIZE_MAX STDERR_FILENO STDIN_FILENO STDOUT_FILENO STREAM_MAX S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISGID S_ISREGSUID S_IWGRP S_IWOTH S_IWUSR S_IXGRP S_IXOTH S_IXUSR TCIFLUSH TCIOFF TCIOFLUSH TCION TCOFLUSH TCOFF TCOON TCSADRAIN TCSAFLUSH TCSANOW TOSTOP TZNAME_MAX VEOF VEOL VERASE VINTR VKILL VMIN VQUIT VSTART VSTOP VSUSP VTIME WEXITSTATUS WIFEXITED WIFSIGNALED WIFSTOPPED WNOHANG WSTOPSIG WTERMSIG WUNTRACED W_OK X_OK _PC_MAX_CANON _PC_MAX_INPUT _PC_NAME_MAX _PC_NO_TRUNC _PC_PATH_MAX _PC_PIPE_BUF _PC_VDISABLE _POSIX_ARG_MAX _POSIX_CHILD_MAX _POSIX_JOB_CONTROL _POSIX_LINK_MAX _POSIX_MAX_CANON _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX _POSIX_NO_TRUNC _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_SAVED_IDS _POSIX_SSIZE_MAX _POSIX_STREAM_MAX _POSIX_TZNAME_MAX _POSIX_VDISABLE _POSIX_VERSION _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CONTROL _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_SAVED_IDS _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION _PC_CHOWN_RESTRICTED _POSIX_CHOWN_RESTRICTED Standard C defined data types in ANSI (ISO/IEC 9899:1990) clock_t div_t FILE fpos_t jmp_buf struct lconv ldiv_t ptrdiff_t sig_atomic_t size_t time_t struct tm va_list wchar_t Additional C data types defined by NCEG fenv_t fexcept_t Additional C data types defined in Posix.1 cc_t dev_t DIR gid_t ino_t mode_t nlink_t off_t pid_t struct passwd sigjmp_buf sigset_t sigaction speed_t ssize_t struct stat tcflag_t struct termios uid_t struct utsname Standard C global variables in ANSI (ISO/IEC 9899:1990) errno stderr stdin stdout