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

   1 // Wrapper of C-language FILE struct -*- C++ -*-
   2
   3 // Copyright (C) 2000, 2001, 2002, 2003 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 #include <unistd.h>
  37 #include <errno.h>
  38
  39 #ifdef _GLIBCPP_HAVE_SYS_IOCTL_H
  40 #define BSD_COMP /* Get FIONREAD on Solaris2. */
  41 #include <sys/ioctl.h>
  42 #endif
  43
  44 // Pick up FIONREAD on Solaris 2.5.
  45 #ifdef _GLIBCPP_HAVE_SYS_FILIO_H
  46 #include <sys/filio.h>
  47 #endif
  48
  49 #ifdef _GLIBCPP_HAVE_POLL
  50 #include <poll.h>
  51 #endif
  52
  53 #if defined(_GLIBCPP_HAVE_S_ISREG) || defined(_GLIBCPP_HAVE_S_IFREG)
  54 # include <sys/stat.h>
  55 # ifdef _GLIBCPP_HAVE_S_ISREG
  56 #  define _GLIBCPP_ISREG(x) S_ISREG(x)
  57 # else
  58 #  define _GLIBCPP_ISREG(x) (((x) & S_IFMT) == S_IFREG)
  59 # endif
  60 #endif
  61
  62 namespace std
  63 {
  64   // Definitions for __basic_file<char>.
  65   __basic_file<char>::__basic_file(__c_lock* /*__lock*/)
  66   : _M_cfile(NULL), _M_cfile_created(false) { }
  67
  68   __basic_file<char>::~__basic_file()
  69   { this->close(); }
  70
  71   void
  72   __basic_file<char>::_M_open_mode(ios_base::openmode __mode, int& __p_mode,
  73                                    int&, char* __c_mode)
  74   {
  75     bool __testb = __mode & ios_base::binary;
  76     bool __testi = __mode & ios_base::in;
  77     bool __testo = __mode & ios_base::out;
  78     bool __testt = __mode & ios_base::trunc;
  79     bool __testa = __mode & ios_base::app;
  80
  81     // Set __c_mode for use in fopen.
  82     // Set __p_mode for use in open.
  83     if (!__testi && __testo && !__testt && !__testa)
  84       {
  85         strcpy(__c_mode, "w");
  86         __p_mode = (O_WRONLY | O_CREAT);
  87       }
  88     if (!__testi && __testo && !__testt && __testa)
  89       {
  90         strcpy(__c_mode, "a");
  91         __p_mode |=  O_WRONLY | O_CREAT | O_APPEND;
  92       }
  93     if (!__testi && __testo && __testt && !__testa)
  94       {
  95         strcpy(__c_mode, "w");
  96         __p_mode |=  O_WRONLY | O_CREAT | O_TRUNC;
  97       }
  98
  99     if (__testi && !__testo && !__testt && !__testa)
 100       {
 101         strcpy(__c_mode, "r");
 102         __p_mode |=  O_RDONLY;
 103       }
 104     if (__testi && __testo && !__testt && !__testa)
 105       {
 106         strcpy(__c_mode, "r+");
 107         __p_mode |=  O_RDWR | O_CREAT;
 108       }
 109     if (__testi && __testo && __testt && !__testa)
 110       {
 111         strcpy(__c_mode, "w+");
 112         __p_mode |=  O_RDWR | O_CREAT | O_TRUNC;
 113       }
 114     if (__testb)
 115       strcat(__c_mode, "b");
 116   }
 117
 118   __basic_file<char>*
 119   __basic_file<char>::sys_open(__c_file* __file, ios_base::openmode)
 120   {
 121     __basic_file* __ret = NULL;
 122     if (!this->is_open() && __file)
 123       {
 124         _M_cfile = __file;
 125         _M_cfile_created = false;
 126         __ret = this;
 127       }
 128     return __ret;
 129   }
 130
 131   __basic_file<char>*
 132   __basic_file<char>::sys_open(int __fd, ios_base::openmode __mode,
 133                                bool __del)
 134   {
 135     __basic_file* __ret = NULL;
 136     int __p_mode = 0;
 137     int __rw_mode = 0;
 138     char __c_mode[4];
 139
 140     _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
 141     if (!this->is_open() && (_M_cfile = fdopen(__fd, __c_mode)))
 142       {
 143         // Iff __del is true, then close will fclose the fd.
 144         _M_cfile_created = __del;
 145
 146         if (__fd == 0)
 147           setvbuf(_M_cfile, reinterpret_cast<char*>(NULL), _IONBF, 0);
 148
 149         __ret = this;
 150       }
 151     return __ret;
 152   }
 153
 154   int
 155   __basic_file<char>::sys_getc()
 156   { return getc(_M_cfile); }
 157
 158   int
 159   __basic_file<char>::sys_ungetc(int __c)
 160   { return ungetc(__c, _M_cfile); }
 161
 162   __basic_file<char>*
 163   __basic_file<char>::open(const char* __name, ios_base::openmode __mode,
 164                            int /*__prot*/)
 165   {
 166     __basic_file* __ret = NULL;
 167     int __p_mode = 0;
 168     int __rw_mode = 0;
 169     char __c_mode[4];
 170
 171     _M_open_mode(__mode, __p_mode, __rw_mode, __c_mode);
 172
 173     if (!this->is_open())
 174       {
 175         if ((_M_cfile = fopen(__name, __c_mode)))
 176           {
 177             _M_cfile_created = true;
 178             __ret = this;
 179           }
 180       }
 181     return __ret;
 182   }
 183
 184   bool
 185   __basic_file<char>::is_open() const
 186   { return _M_cfile != 0; }
 187
 188   int
 189   __basic_file<char>::fd()
 190   { return fileno(_M_cfile) ; }
 191
 192   __basic_file<char>*
 193   __basic_file<char>::close()
 194   {
 195     __basic_file* __retval = static_cast<__basic_file*>(NULL);
 196     if (this->is_open())
 197       {
 198         if (_M_cfile_created)
 199           fclose(_M_cfile);
 200         else
 201           fflush(_M_cfile);
 202         _M_cfile = 0;
 203         __retval = this;
 204       }
 205     return __retval;
 206   }
 207
 208   streamsize
 209   __basic_file<char>::xsgetn(char* __s, streamsize __n)
 210   {
 211     streamsize __ret;
 212     do
 213       __ret = read(this->fd(), __s, __n);
 214     while (__ret == -1L && errno == EINTR);
 215     return __ret;
 216   }
 217
 218   streamsize
 219   __basic_file<char>::xsputn(const char* __s, streamsize __n)
 220   {
 221     streamsize __ret;
 222     do
 223       __ret = write(this->fd(), __s, __n);
 224     while (__ret == -1L && errno == EINTR);
 225     return __ret;
 226   }
 227
 228   streamoff
 229   __basic_file<char>::seekoff(streamoff __off, ios_base::seekdir __way,
 230                               ios_base::openmode /*__mode*/)
 231   { return lseek(this->fd(), __off, __way); }
 232
 233   streamoff
 234   __basic_file<char>::seekpos(streamoff __pos, ios_base::openmode /*__mode*/)
 235   { return lseek(this->fd(), __pos, ios_base::beg); }
 236
 237   int
 238   __basic_file<char>::sync()
 239   { return fflush(_M_cfile); }
 240
 241   streamsize
 242   __basic_file<char>::showmanyc()
 243   {
 244 #ifdef FIONREAD
 245     // Pipes and sockets.
 246     int __num = 0;
 247     int __r = ioctl(this->fd(), FIONREAD, &__num);
 248     if (!__r && __num >= 0)
 249       return __num;
 250 #endif
 251
 252 #ifdef _GLIBCPP_HAVE_POLL
 253     // Cheap test.
 254     struct pollfd __pfd[1];
 255     __pfd[0].fd = this->fd();
 256     __pfd[0].events = POLLIN;
 257     if (poll(__pfd, 1, 0) <= 0)
 258       return 0;
 259 #endif
 260
 261 #if defined(_GLIBCPP_HAVE_S_ISREG) || defined(_GLIBCPP_HAVE_S_IFREG)
 262     // Regular files.
 263     struct stat __buffer;
 264     int __ret = fstat(this->fd(), &__buffer);
 265     if (!__ret && _GLIBCPP_ISREG(__buffer.st_mode))
 266         return __buffer.st_size - lseek(this->fd(), 0, ios_base::cur);
 267 #endif
 268     return 0;
 269   }
 270
 271 }  // namespace std