NAME

       getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - nonlocking stdio functions

SYNOPSIS

       #include <stdio.h>

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

       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);

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

       #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);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       getc_unlocked(), getchar_unlocked(), putc_unlocked(), putchar_unlocked():
           /* Since glibc 2.24: */ _POSIX_C_SOURCE >= 199309L
               || /* Glibc versions <= 2.23: */ _POSIX_C_SOURCE
               || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

       clearerr_unlocked(), feof_unlocked(), ferror_unlocked(), fileno_unlocked(), fflush_unlocked(),
       fgetc_unlocked(), fputc_unlocked(), fread_unlocked(), fwrite_unlocked():
           /* Glibc since 2.19: */ _DEFAULT_SOURCE
               || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

       fgets_unlocked(), fputs_unlocked(), getwc_unlocked(), getwchar_unlocked(), fgetwc_unlocked(),
       fputwc_unlocked(), putwchar_unlocked(), fgetws_unlocked(), fputws_unlocked():
           _GNU_SOURCE

DESCRIPTION

       Each  of  these functions has the same behavior as its counterpart without the "_unlocked" suffix, except
       that they do not use locking (they do not set locks themselves, and do not test for the presence of locks
       set by others) and hence are thread-unsafe.  See flockfile(3).

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌─────────────────────┬───────────────┬───────────────────────┐
       │Interface            │ Attribute     │ Value                 │
       ├─────────────────────┼───────────────┼───────────────────────┤
       │getc_unlocked(),     │ Thread safety │ MT-Safe race:stream   │
       │putc_unlocked(),     │               │                       │
       │clearerr_unlocked(), │               │                       │
       │fflush_unlocked(),   │               │                       │
       │fgetc_unlocked(),    │               │                       │
       │fputc_unlocked(),    │               │                       │
       │fread_unlocked(),    │               │                       │
       │fwrite_unlocked(),   │               │                       │
       │fgets_unlocked(),    │               │                       │
       │fputs_unlocked(),    │               │                       │
       │getwc_unlocked(),    │               │                       │
       │fgetwc_unlocked(),   │               │                       │
       │fputwc_unlocked(),   │               │                       │
       │putwc_unlocked(),    │               │                       │
       │fgetws_unlocked(),   │               │                       │
       │fputws_unlocked()    │               │                       │
       ├─────────────────────┼───────────────┼───────────────────────┤
       │getchar_unlocked(),  │ Thread safety │ MT-Unsafe race:stdin  │
       │getwchar_unlocked()  │               │                       │
       ├─────────────────────┼───────────────┼───────────────────────┤
       │putchar_unlocked(),  │ Thread safety │ MT-Unsafe race:stdout │
       │putwchar_unlocked()  │               │                       │
       ├─────────────────────┼───────────────┼───────────────────────┤
       │feof_unlocked(),     │ Thread safety │ MT-Safe               │
       │ferror_unlocked(),   │               │                       │
       │fileno_unlocked()    │               │                       │
       └─────────────────────┴───────────────┴───────────────────────┘

CONFORMING TO

       The four  functions  getc_unlocked(),  getchar_unlocked(),  putc_unlocked(),  putchar_unlocked()  are  in
       POSIX.1-2001 and POSIX.1-2008.

       The  nonstandard  *_unlocked()  variants  occur on a few UNIX systems, and are available in recent glibc.
       They should probably not be used.

SEE ALSO

       flockfile(3), stdio(3)

COLOPHON

       This page is part of release 5.05 of  the  Linux  man-pages  project.   A  description  of  the  project,
       information   about   reporting   bugs,   and   the  latest  version  of  this  page,  can  be  found  at
       https://www.kernel.org/doc/man-pages/.

                                                   2017-09-15                                  UNLOCKED_STDIO(3)