.\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>.

.\"

.\" %%%LICENSE_START(VERBATIM)

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.\" %%%LICENSE_END

.\"

.TH UNLOCKED_STDIO 3  2017-09-15 "" "Linux Programmer's Manual"

.SH NAME

getc_unlocked, getchar_unlocked, putc_unlocked,

putchar_unlocked \- nonlocking stdio functions

.SH SYNOPSIS

.nf

.B #include <stdio.h>

.PP

.BI "int getc_unlocked(FILE *" stream );

.B "int getchar_unlocked(void);"

.BI "int putc_unlocked(int " c ", FILE *" stream );

.BI "int putchar_unlocked(int " c );

.PP

.BI "void clearerr_unlocked(FILE *" stream );

.BI "int feof_unlocked(FILE *" stream );

.BI "int ferror_unlocked(FILE *" stream );

.BI "int fileno_unlocked(FILE *" stream );

.BI "int fflush_unlocked(FILE *" stream );

.BI "int fgetc_unlocked(FILE *" stream );

.BI "int fputc_unlocked(int " c ", FILE *" stream );

.BI "size_t fread_unlocked(void *" ptr ", size_t " size ", size_t " n ,

.BI "                      FILE *" stream );

.BI "size_t fwrite_unlocked(const void *" ptr ", size_t " size ", size_t " n ,

.BI "                      FILE *" stream );

.PP

.BI "char *fgets_unlocked(char *" s ", int " n ", FILE *" stream );

.BI "int fputs_unlocked(const char *" s ", FILE *" stream );

.B #include <wchar.h>

.PP

.BI "wint_t getwc_unlocked(FILE *" stream );

.B "wint_t getwchar_unlocked(void);"

.BI "wint_t fgetwc_unlocked(FILE *" stream );

.BI "wint_t fputwc_unlocked(wchar_t " wc ", FILE *" stream );

.BI "wint_t putwc_unlocked(wchar_t " wc ", FILE *" stream );

.BI "wint_t putwchar_unlocked(wchar_t " wc );

.BI "wchar_t *fgetws_unlocked(wchar_t *" ws ", int " n ", FILE *" stream );

.BI "int fputws_unlocked(const wchar_t *" ws ", FILE *" stream );

.fi

.PP

.in -4n

Feature Test Macro Requirements for glibc (see

.BR feature_test_macros (7)):

.ad l

.in

.PP

.BR getc_unlocked (),

.BR getchar_unlocked (),

.BR putc_unlocked (),

.BR putchar_unlocked ():

.RS 4

/* Since glibc 2.24: */ _POSIX_C_SOURCE\ >=\ 199309L

    || /* Glibc versions <= 2.23: */ _POSIX_C_SOURCE

    || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

.RE

.PP

.BR clearerr_unlocked (),

.BR feof_unlocked (),

.BR ferror_unlocked (),

.BR fileno_unlocked (),

.BR fflush_unlocked (),

.BR fgetc_unlocked (),

.BR fputc_unlocked (),

.BR fread_unlocked (),

.BR fwrite_unlocked ():

.RS 4

/* Glibc since 2.19: */ _DEFAULT_SOURCE

    || /* Glibc versions <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE

.RE

.PP

.BR fgets_unlocked (),

.BR fputs_unlocked (),

.BR getwc_unlocked (),

.BR getwchar_unlocked (),

.BR fgetwc_unlocked (),

.BR fputwc_unlocked (),

.BR putwchar_unlocked (),

.BR fgetws_unlocked (),

.BR fputws_unlocked ():

.RS 4

_GNU_SOURCE

.RE

.ad b

.SH 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

.BR flockfile (3).

.SH ATTRIBUTES

For an explanation of the terms used in this section, see

.BR attributes (7).

.ad l

.TS

allbox;

lbw20 lb lb

l l l.

Interface	Attribute	Value

T{

.BR getc_unlocked (),

.BR putc_unlocked (),

.BR clearerr_unlocked (),

.BR fflush_unlocked (),

.BR fgetc_unlocked (),

.BR fputc_unlocked (),

.BR fread_unlocked (),

.BR fwrite_unlocked (),

.BR fgets_unlocked (),

.BR fputs_unlocked (),

.BR getwc_unlocked (),

.BR fgetwc_unlocked (),

.BR fputwc_unlocked (),

.BR putwc_unlocked (),

.BR fgetws_unlocked (),

.BR fputws_unlocked ()

T}	Thread safety	MT-Safe race:stream

T{

.BR getchar_unlocked (),

.BR getwchar_unlocked ()

T}	Thread safety	MT-Unsafe race:stdin

T{

.BR putchar_unlocked (),

.BR putwchar_unlocked ()

T}	Thread safety	MT-Unsafe race:stdout

T{

.BR feof_unlocked (),

.BR ferror_unlocked (),

.BR fileno_unlocked ()

T}	Thread safety	MT-Safe

.TE

.ad

.SH CONFORMING TO

The four functions

.BR getc_unlocked (),

.BR getchar_unlocked (),

.BR putc_unlocked (),

.BR putchar_unlocked ()

are in POSIX.1-2001 and POSIX.1-2008.

.PP

The nonstandard

.BR *_unlocked ()

variants occur on a few UNIX systems, and are available in recent glibc.

.\" E.g., in HP-UX 10.0. In HP-UX 10.30 they are called obsolescent, and

.\" moved to a compatibility library.

.\" Available in HP-UX 10.0: clearerr_unlocked, fclose_unlocked,

.\" feof_unlocked, ferror_unlocked, fflush_unlocked, fgets_unlocked,

.\" fgetwc_unlocked, fgetws_unlocked, fileno_unlocked, fputs_unlocked,

.\" fputwc_unlocked, fputws_unlocked, fread_unlocked, fseek_unlocked,

.\" ftell_unlocked, fwrite_unlocked, getc_unlocked, getchar_unlocked,

.\" getw_unlocked, getwc_unlocked, getwchar_unlocked, putc_unlocked,

.\" putchar_unlocked, puts_unlocked, putws_unlocked, putw_unlocked,

.\" putwc_unlocked, putwchar_unlocked, rewind_unlocked, setvbuf_unlocked,

.\" ungetc_unlocked, ungetwc_unlocked.

They should probably not be used.

.SH SEE ALSO

.BR flockfile (3),

.BR stdio (3)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I 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/.