getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - nonlocking
stdio functions
#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
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).
For an explanation of the terms used in this section, see
attributes(7).
Interface |
Attribute |
Value |
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 () |
Thread safety |
MT-Safe race:stream |
getchar_unlocked (), getwchar_unlocked () |
Thread safety |
MT-Unsafe race:stdin |
putchar_unlocked (), putwchar_unlocked () |
Thread safety |
MT-Unsafe race:stdout |
feof_unlocked (), ferror_unlocked (), fileno_unlocked () |
Thread safety |
MT-Safe |
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.
flockfile(3),
stdio(3)