include/stdio_ext.h

   1 /* Functions to access FILE structure internals.
   2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* This header contains the same definitions as the header of the same name
  20    on Sun's Solaris OS.  */
  21
  22 #ifndef _STDIO_EXT_H
  23 #define _STDIO_EXT_H    1
  24
  25 #include <stdio.h>
  26
  27 enum
  28 {
  29   /* Query current state of the locking status.  */
  30   FSETLOCKING_QUERY = 0,
  31 #define FSETLOCKING_QUERY       FSETLOCKING_QUERY
  32   /* The library protects all uses of the stream functions, except for
  33      uses of the *_unlocked functions, by calls equivalent to flockfile().  */
  34   FSETLOCKING_INTERNAL,
  35 #define FSETLOCKING_INTERNAL    FSETLOCKING_INTERNAL
  36   /* The user will take care of locking.  */
  37   FSETLOCKING_BYCALLER
  38 #define FSETLOCKING_BYCALLER    FSETLOCKING_BYCALLER
  39 };
  40
  41
  42 __BEGIN_DECLS
  43
  44 /* Return the size of the buffer of FP in bytes currently in use by
  45    the given stream.  */
  46 extern size_t __fbufsize (FILE *__fp) __THROW;
  47
  48
  49 /* Return non-zero value iff the stream FP is opened readonly, or if the
  50    last operation on the stream was a read operation.  */
  51 extern int __freading (FILE *__fp) __THROW;
  52
  53 /* Return non-zero value iff the stream FP is opened write-only or
  54    append-only, or if the last operation on the stream was a write
  55    operation.  */
  56 extern int __fwriting (FILE *__fp) __THROW;
  57
  58
  59 /* Return non-zero value iff stream FP is not opened write-only or
  60    append-only.  */
  61 extern int __freadable (FILE *__fp) __THROW;
  62
  63 /* Return non-zero value iff stream FP is not opened read-only.  */
  64 extern int __fwritable (FILE *__fp) __THROW;
  65
  66
  67 /* Return non-zero value iff the stream FP is line-buffered.  */
  68 extern int __flbf (FILE *__fp) __THROW;
  69
  70
  71 /* Discard all pending buffered I/O on the stream FP.  */
  72 extern void __fpurge (FILE *__fp) __THROW;
  73
  74 /* Return amount of output in bytes pending on a stream FP.  */
  75 extern size_t __fpending (FILE *__fp) __THROW;
  76
  77 /* Flush all line-buffered files.  */
  78 extern void _flushlbf (void);
  79
  80
  81 /* Set locking status of stream FP to TYPE.  */
  82 extern int __fsetlocking (FILE *__fp, int __type) __THROW;
  83
  84 __END_DECLS
  85
  86 #endif  /* stdio_ext.h */