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



NAME
       getc_unlocked,  getchar_unlocked, putc_unlocked, putchar_unlocked - nonlocking stdio func‐
       tions

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():
           _POSIX_C_SOURCE >= 1 || _XOPEN_SOURCE || _POSIX_SOURCE || _BSD_SOURCE || _SVID_SOURCE

       clearerr_unlocked(), feof_unlocked(), ferror_unlocked(), fileno_unlocked(),
       fflush_unlocked(), fgetc_unlocked(), fputc_unlocked(), fread_unlocked(),
       fwrite_unlocked():
           _BSD_SOURCE || _SVID_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  flock‐
       file(3).

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

       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 3.74 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 http://www.kernel.org/doc/man-pages/.



                                            2008-08-29                          UNLOCKED_STDIO(3)