unlocked_stdio(3) — Linux manual page

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON

unlocked_stdio(3)       Library Functions Manual       unlocked_stdio(3)

NAME         top

       getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked
       - nonlocking stdio functions

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #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 *_Nullable stream);

       int fgetc_unlocked(FILE *stream);
       int fputc_unlocked(int c, FILE *stream);

       size_t fread_unlocked(void ptr[restrict .size * .n],
                             size_t size, size_t n,
                             FILE *restrict stream);
       size_t fwrite_unlocked(const void ptr[restrict .size * .n],
                             size_t size, size_t n,
                             FILE *restrict stream);

       char *fgets_unlocked(char s[restrict .n], int n, FILE *restrict stream);
       int fputs_unlocked(const char *restrict s, FILE *restrict 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[restrict .n], int n,
                             FILE *restrict stream);
       int fputws_unlocked(const wchar_t *restrict ws,
                             FILE *restrict stream);

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

       getc_unlocked(), getchar_unlocked(), putc_unlocked(),
       putchar_unlocked():
           /* glibc >= 2.24: */ _POSIX_C_SOURCE >= 199309L
               || /* glibc <= 2.23: */ _POSIX_C_SOURCE
               || /* glibc <= 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 >= 2.19: */ _DEFAULT_SOURCE
               || /* glibc <= 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         top

       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         top

       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()    │               │                        │
       └──────────────────────┴───────────────┴────────────────────────┘

STANDARDS         top

       getc_unlocked()
       getchar_unlocked()
       putc_unlocked()
       putchar_unlocked()
              POSIX.1-2008.

       Others:
              None.

HISTORY         top

       getc_unlocked()
       getchar_unlocked()
       putc_unlocked()
       putchar_unlocked()
              POSIX.1-2001.

SEE ALSO         top

       flockfile(3), stdio(3)

COLOPHON         top

       This page is part of the man-pages (Linux kernel and C library
       user-space interface documentation) project.  Information about
       the project can be found at 
       ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report
       for this manual page, see
       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
       This page was obtained from the tarball man-pages-6.9.1.tar.gz
       fetched from
       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
       2024-06-26.  If you discover any rendering problems in this HTML
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       part of the original manual page), send a mail to
       man-pages@man7.org

Linux man-pages 6.9.1          2024-05-02              unlocked_stdio(3)

Pages that refer to this page: ferror(3)fflush(3)fgetc(3)fgetwc(3)fgetws(3)fileno(3)flockfile(3)fputwc(3)fputws(3)fread(3)gets(3)getwchar(3)puts(3)putwchar(3)stdio(3)