UNLOCKED_STDIO(3)          Linux Programmer's Manual         UNLOCKED_STDIO(3)



NAME
       getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - non-
       locking 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 with-
       out 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).

       allbox; lbw20 lb lb l l l.  Interface Attribute Value T{
       getc_unlocked(), 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() T}   Thread safety  MT-Safe race:stream T{
       getchar_unlocked(), getwchar_unlocked() T}   Thread safety  MT-Unsafe
       race:stdin T{ putchar_unlocked(), putwchar_unlocked() T}   Thread
       safety  MT-Unsafe race:stdout T{ feof_unlocked(), ferror_unlocked(),
       fileno_unlocked() T}   Thread safety  MT-Safe

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 4.16 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)