libstdc++-v3/config/io/basic_file_stdio.cc

   1 // Wrapper of C-language FILE struct -*- C++ -*-
   2
   3 // Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 //
  31 // ISO C++ 14882: 27.8  File-based streams
  32 //
  33
  34 #include <bits/basic_file.h>
  35 #include <fcntl.h>
  36
  37 namespace std
  38 {
  39   // Definitions for __basic_file<char>.
  40   __basic_file<char>::__basic_file(__c_lock* /*__lock*/)
  41   : _M_cfile(NULL), _M_cfile_created(false) { }
  42
  43   __basic_file<char>::~__basic_file()
  44   { this->close(); }
  45
  46   void
  47   __basic_file<char>::_M_open_mode(ios_base::openmode __mode, int& __p_mode,
  48                                    int&, char* __c_mode)
  49   {
  50     bool __testb = __mode & ios_base::binary;
  51     bool __testi = __mode & ios_base::in;
  52     bool __testo = __mode & ios_base::out;
  53     bool __testt = __mode & ios_base::trunc;
  54     bool __testa = __mode & ios_base::app;
  55
  56     // Set __c_mode for use in fopen.
  57     // Set __p_mode for use in open.
  58     if (!__testi && __testo && !__testt && !__testa)
  59       {
  60         strcpy(__c_mode, "w");
  61         __p_mode = (O_WRONLY | O_CREAT);
  62       }
  63     if (!__testi && __testo && !__testt && __testa)
  64       {
  65         strcpy(__c_mode, "a");
  66         __p_mode |=  O_WRONLY | O_CREAT | O_APPEND;
  67       }
  68     if (!__testi && __testo && __testt && !__testa)
  69       {
  70         strcpy(__c_mode, "w");
  71         __p_mode |=  O_WRONLY | O_CREAT | O_TRUNC;
  72       }
  73
  74     if (__testi && !__testo && !__testt && !__testa)
  75       {
  76         strcpy(__c_mode, "r");
  77 #if defined (O_NONBLOCK)
  78         __p_mode |=  O_RDONLY | O_NONBLOCK;
  79 #else
  80         __p_mode |=  O_RDONLY;
  81 #endif
  82       }
  83     if (__testi && __testo && !__testt && !__testa)
  84       {
  85         strcpy(__c_mode, "r+");
  86         __p_mode |=  O_RDWR | O_CREAT;
  87       }
  88     if (__testi && __testo && __testt && !__testa)
  89       {
  90         strcpy(__c_mode, "w+");
  91         __p_mode |=  O_RDWR | O_CREAT | O_TRUNC;
  92       }
  93     if (__testb)
  94       strcat(__c_mode, "b");
  95   }
  96
  97   __basic_file<char>*
  98   __basic_file<char>::sys_open(__c_file* __file, ios_base::openmode)
  99   {
 100     __basic_file* __ret = NULL;
 101     if (!this->is_open() && __file)
 102       {
 103         _M_cfile = __file;
 104         _M_cfile_created = false;
 105         __ret = this;
 106       }
 107     return __ret;
 108   }
 109
 110   __basic_file<char>*
 111   __basic_file<char>::sys_open(int __fd, ios_base::openmode __mode,
 112                                bool __del)
 113   {
 114     __basic_file* __ret = NULL;
 115     int __p_mode = 0;
 116     int __rw_mode = 0;
 117     char __c_mode[4];
 118
 119     _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
 120     if (!this->is_open() && (_M_cfile = fdopen(__fd, __c_mode)))
 121       {
 122         // Iff __del is true, then close will fclose the fd.
 123         _M_cfile_created = __del;
 124
 125         if (__fd == 0)
 126           setvbuf(_M_cfile, reinterpret_cast<char*>(NULL), _IONBF, 0);
 127
 128         __ret = this;
 129       }
 130     return __ret;
 131   }
 132
 133   int
 134   __basic_file<char>::sys_getc()
 135   { return getc(_M_cfile); }
 136
 137   int
 138   __basic_file<char>::sys_ungetc(int __c)
 139   { return ungetc(__c, _M_cfile); }
 140
 141   __basic_file<char>*
 142   __basic_file<char>::open(const char* __name, ios_base::openmode __mode,
 143                            int /*__prot*/)
 144   {
 145     __basic_file* __ret = NULL;
 146     int __p_mode = 0;
 147     int __rw_mode = 0;
 148     char __c_mode[4];
 149
 150     _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
 151
 152     if (!this->is_open())
 153       {
 154         if ((_M_cfile = fopen(__name, __c_mode)))
 155           {
 156             _M_cfile_created = true;
 157
 158 #if defined (F_SETFL) && defined (O_NONBLOCK)
 159             // Set input to nonblocking for fifos.
 160             if (__mode & ios_base::in)
 161               fcntl(this->fd(), F_SETFL, O_NONBLOCK);
 162 #endif
 163
 164             __ret = this;
 165           }
 166       }
 167     return __ret;
 168   }
 169
 170   bool
 171   __basic_file<char>::is_open() const
 172   { return _M_cfile != 0; }
 173
 174   int
 175   __basic_file<char>::fd()
 176   { return fileno(_M_cfile) ; }
 177
 178   __basic_file<char>*
 179   __basic_file<char>::close()
 180   {
 181     __basic_file* __retval = static_cast<__basic_file*>(NULL);
 182     if (this->is_open())
 183       {
 184         fflush(_M_cfile);
 185         if ((_M_cfile_created && fclose(_M_cfile) == 0) || !_M_cfile_created)
 186           {
 187             _M_cfile = 0;
 188             __retval = this;
 189           }
 190       }
 191     return __retval;
 192   }
 193
 194   streamsize
 195   __basic_file<char>::xsgetn(char* __s, streamsize __n)
 196   { return fread(__s, 1, __n, _M_cfile); }
 197
 198   streamsize
 199   __basic_file<char>::xsputn(const char* __s, streamsize __n)
 200   { return fwrite(__s, 1, __n, _M_cfile); }
 201
 202   streamoff
 203   __basic_file<char>::seekoff(streamoff __off, ios_base::seekdir __way,
 204                               ios_base::openmode /*__mode*/)
 205   {
 206     if (!fseek(_M_cfile, __off, __way))
 207       return ftell(_M_cfile);
 208     else
 209       // Fseek failed.
 210       return -1L;
 211   }
 212
 213   streamoff
 214   __basic_file<char>::seekpos(streamoff __pos, ios_base::openmode /*__mode*/)
 215   {
 216     if (!fseek(_M_cfile, __pos, ios_base::beg))
 217       return ftell(_M_cfile);
 218     else
 219       // Fseek failed.
 220       return -1L;
 221   }
 222
 223   int
 224   __basic_file<char>::sync()
 225   { return fflush(_M_cfile); }
 226 }  // namespace std