man3/unlocked_stdio.3

   1 .\" Copyright (C) 2001 Andries Brouwer <aeb@cwi.nl>.
   2 .\"
   3 .\" SPDX-License-Identifier: Linux-man-pages-copyleft
   4 .\"
   5 .TH UNLOCKED_STDIO 3 (date) "Linux man-pages (unreleased)"
   6 .SH NAME
   7 getc_unlocked, getchar_unlocked, putc_unlocked,
   8 putchar_unlocked \- nonlocking stdio functions
   9 .SH LIBRARY
  10 Standard C library
  11 .RI ( libc ", " \-lc )
  12 .SH SYNOPSIS
  13 .nf
  14 .B #include <stdio.h>
  15 .PP
  16 .BI "int getc_unlocked(FILE *" stream );
  17 .B "int getchar_unlocked(void);"
  18 .BI "int putc_unlocked(int " c ", FILE *" stream );
  19 .BI "int putchar_unlocked(int " c );
  20 .PP
  21 .BI "void clearerr_unlocked(FILE *" stream );
  22 .BI "int feof_unlocked(FILE *" stream );
  23 .BI "int ferror_unlocked(FILE *" stream );
  24 .BI "int fileno_unlocked(FILE *" stream );
  25 .BI "int fflush_unlocked(FILE *" stream );
  26 .PP
  27 .BI "int fgetc_unlocked(FILE *" stream );
  28 .BI "int fputc_unlocked(int " c ", FILE *" stream );
  29 .PP
  30 .BI "size_t fread_unlocked(void " ptr "[restrict ." size " * ." n ],
  31 .BI "                      size_t " size ", size_t " n ,
  32 .BI "                      FILE *restrict " stream );
  33 .BI "size_t fwrite_unlocked(const void " ptr "[restrict ." size " * ." n ],
  34 .BI "                      size_t " size ", size_t " n ,
  35 .BI "                      FILE *restrict " stream );
  36 .PP
  37 .BI "char *fgets_unlocked(char " s "[restrict ." n "], int " n \
  38 ", FILE *restrict " stream );
  39 .BI "int fputs_unlocked(const char *restrict " s ", FILE *restrict " stream );
  40 .PP
  41 .B #include <wchar.h>
  42 .PP
  43 .BI "wint_t getwc_unlocked(FILE *" stream );
  44 .B "wint_t getwchar_unlocked(void);"
  45 .BI "wint_t fgetwc_unlocked(FILE *" stream );
  46 .PP
  47 .BI "wint_t fputwc_unlocked(wchar_t " wc ", FILE *" stream );
  48 .BI "wint_t putwc_unlocked(wchar_t " wc ", FILE *" stream );
  49 .BI "wint_t putwchar_unlocked(wchar_t " wc );
  50 .PP
  51 .BI "wchar_t *fgetws_unlocked(wchar_t " ws "[restrict ." n "], int " n ,
  52 .BI "                      FILE *restrict " stream );
  53 .BI "int fputws_unlocked(const wchar_t *restrict " ws ,
  54 .BI "                      FILE *restrict " stream );
  55 .fi
  56 .PP
  57 .RS -4
  58 Feature Test Macro Requirements for glibc (see
  59 .BR feature_test_macros (7)):
  60 .nh
  61 .RE
  62 .ad l
  63 .PP
  64 .BR getc_unlocked (),
  65 .BR getchar_unlocked (),
  66 .BR putc_unlocked (),
  67 .BR putchar_unlocked ():
  68 .nf
  69     /* Glibc >= 2.24: */ _POSIX_C_SOURCE >= 199309L
  70         || /* Glibc <= 2.23: */ _POSIX_C_SOURCE
  71         || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
  72 .fi
  73 .PP
  74 .BR clearerr_unlocked (),
  75 .BR feof_unlocked (),
  76 .BR ferror_unlocked (),
  77 .BR fileno_unlocked (),
  78 .BR fflush_unlocked (),
  79 .BR fgetc_unlocked (),
  80 .BR fputc_unlocked (),
  81 .BR fread_unlocked (),
  82 .BR fwrite_unlocked ():
  83 .nf
  84     /* Glibc >= 2.19: */ _DEFAULT_SOURCE
  85         || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
  86 .fi
  87 .PP
  88 .BR fgets_unlocked (),
  89 .BR fputs_unlocked (),
  90 .BR getwc_unlocked (),
  91 .BR getwchar_unlocked (),
  92 .BR fgetwc_unlocked (),
  93 .BR fputwc_unlocked (),
  94 .BR putwchar_unlocked (),
  95 .BR fgetws_unlocked (),
  96 .BR fputws_unlocked ():
  97 .nf
  98     _GNU_SOURCE
  99 .fi
 100 .hy
 101 .ad
 102 .SH DESCRIPTION
 103 Each of these functions has the same behavior as its counterpart
 104 without the "_unlocked" suffix, except that they do not use locking
 105 (they do not set locks themselves, and do not test for the presence
 106 of locks set by others) and hence are thread-unsafe.
 107 See
 108 .BR flockfile (3).
 109 .SH ATTRIBUTES
 110 For an explanation of the terms used in this section, see
 111 .BR attributes (7).
 112 .ad l
 113 .nh
 114 .TS
 115 allbox;
 116 lb lb lbx
 117 l l l.
 118 Interface       Attribute       Value
 119 T{
 120 .BR getc_unlocked (),
 121 .BR putc_unlocked (),
 122 .BR clearerr_unlocked (),
 123 .BR fflush_unlocked (),
 124 .BR fgetc_unlocked (),
 125 .BR fputc_unlocked (),
 126 .BR fread_unlocked (),
 127 .BR fwrite_unlocked (),
 128 .BR fgets_unlocked (),
 129 .BR fputs_unlocked (),
 130 .BR getwc_unlocked (),
 131 .BR fgetwc_unlocked (),
 132 .BR fputwc_unlocked (),
 133 .BR putwc_unlocked (),
 134 .BR fgetws_unlocked (),
 135 .BR fputws_unlocked ()
 136 T}      Thread safety   T{
 137 MT-Safe race:stream
 138 T}
 139 T{
 140 .BR getchar_unlocked (),
 141 .BR getwchar_unlocked ()
 142 T}      Thread safety   T{
 143 MT-Unsafe race:stdin
 144 T}
 145 T{
 146 .BR putchar_unlocked (),
 147 .BR putwchar_unlocked ()
 148 T}      Thread safety   T{
 149 MT-Unsafe race:stdout
 150 T}
 151 T{
 152 .BR feof_unlocked (),
 153 .BR ferror_unlocked (),
 154 .BR fileno_unlocked ()
 155 T}      Thread safety   MT-Safe
 156 .TE
 157 .hy
 158 .ad
 159 .sp 1
 160 .SH STANDARDS
 161 The four functions
 162 .BR getc_unlocked (),
 163 .BR getchar_unlocked (),
 164 .BR putc_unlocked (),
 165 .BR putchar_unlocked ()
 166 are in POSIX.1-2001 and POSIX.1-2008.
 167 .PP
 168 The nonstandard
 169 .BR *_unlocked ()
 170 variants occur on a few UNIX systems, and are available in recent glibc.
 171 .\" E.g., in HP-UX 10.0. In HP-UX 10.30 they are called obsolescent, and
 172 .\" moved to a compatibility library.
 173 .\" Available in HP-UX 10.0: clearerr_unlocked, fclose_unlocked,
 174 .\" feof_unlocked, ferror_unlocked, fflush_unlocked, fgets_unlocked,
 175 .\" fgetwc_unlocked, fgetws_unlocked, fileno_unlocked, fputs_unlocked,
 176 .\" fputwc_unlocked, fputws_unlocked, fread_unlocked, fseek_unlocked,
 177 .\" ftell_unlocked, fwrite_unlocked, getc_unlocked, getchar_unlocked,
 178 .\" getw_unlocked, getwc_unlocked, getwchar_unlocked, putc_unlocked,
 179 .\" putchar_unlocked, puts_unlocked, putws_unlocked, putw_unlocked,
 180 .\" putwc_unlocked, putwchar_unlocked, rewind_unlocked, setvbuf_unlocked,
 181 .\" ungetc_unlocked, ungetwc_unlocked.
 182 They should probably not be used.
 183 .SH SEE ALSO
 184 .BR flockfile (3),
 185 .BR stdio (3)