unlocked - unlatched standard input and output functions

SYNOPSIS Overview

#include <stdio.h>

int getc_unlocked(FILE *stream);
int getchar_unlocked(void);
int putc_unlocked(int c, FILE *stream);
int putchar_unlocked(int c);

#define _BSD_SOURCE /* or _SVID_SOURCE or _GNU_SOURCE */
#include <stdio.h>

void clearerr_unlocked(FILE *stream);
int feof_unlocked(FILE *stream);
int ferror_unlocked(FILE *stream);
int fileno_unlocked(FILE *stream);
int fflush_unlocked(FILE *stream);
int fgetc_unlocked(FILE *stream);
int fputc_unlocked(int c, FILE *stream);
size_t fread_unlocked(void *ptr, size_t size, size_t n,
  FILE *stream);
size_t fwrite_unlocked(const void *ptr, size_t size, size_t n,
  FILE *stream);

#define _GNU_SOURCE
#include <stdio.h>

char *fgets_unlocked(char *s, int n, FILE *stream);
int fputs_unlocked(const char *s, FILE *stream);

#define _GNU_SOURCE
#include <wchar.h>

wint_t getwc_unlocked(FILE *stream);
wint_t getwchar_unlocked(void);
wint_t fgetwc_unlocked(FILE *stream);
wint_t fputwc_unlocked(wchar_t wc, FILE *stream);
wint_t putwc_unlocked(wchar_t wc, FILE *stream);
wint_t putwchar_unlocked(wchar_t wc);
wchar_t *fgetws_unlocked(wchar_t *ws, int n, FILE *stream);
int fputws_unlocked(const wchar_t *ws, FILE *stream);

DESCRIPTION Description

Each of these functions are not `_unlocked` behavior consistent with the corresponding version of the suffix with it, but they do not use lock (they do not set their own lock, nor to determine whether there are other function sets the lock), and therefore not thread-safe. See flockfile (3).

CONFORMING TO standard reference

The following four functions getc_unlocked (), getchar_unlocked (), putc_unlocked (), putchar_unlocked () contained in the POSIX.1. Nonstandard * _unlocked () variant appeared in a few Unix systems, the newer glibc also provides them. They should not be used.