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

   1 // Wrapper of C-language FILE struct -*- C++ -*-
   2
   3 // Copyright (C) 2000, 2001, 2002, 2003, 2004 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 <errno.h>
  37
  38 #ifdef _GLIBCXX_HAVE_POLL
  39 #include <poll.h>
  40 #endif
  41
  42 // Pick up ioctl on Solaris 2.8
  43 #ifdef _GLIBCXX_HAVE_UNISTD_H
  44 #include <unistd.h>
  45 #endif
  46
  47 // Pick up FIONREAD on Solaris 2
  48 #ifdef _GLIBCXX_HAVE_SYS_IOCTL_H
  49 #define BSD_COMP
  50 #include <sys/ioctl.h>
  51 #endif
  52
  53 // Pick up FIONREAD on Solaris 2.5.
  54 #ifdef _GLIBCXX_HAVE_SYS_FILIO_H
  55 #include <sys/filio.h>
  56 #endif
  57
  58 #ifdef _GLIBCXX_HAVE_SYS_UIO_H
  59 #include <sys/uio.h>
  60 #endif
  61
  62 #if defined(_GLIBCXX_HAVE_S_ISREG) || defined(_GLIBCXX_HAVE_S_IFREG)
  63 # include <sys/stat.h>
  64 # ifdef _GLIBCXX_HAVE_S_ISREG
  65 #  define _GLIBCXX_ISREG(x) S_ISREG(x)
  66 # else
  67 #  define _GLIBCXX_ISREG(x) (((x) & S_IFMT) == S_IFREG)
  68 # endif
  69 #endif
  70
  71 #include <limits> // For <off_t>::max() and min()
  72
  73 namespace __gnu_internal
  74 {
  75   // Map ios_base::openmode flags to a string for use in fopen().
  76   // Table of valid combinations as given in [lib.filebuf.members]/2.
  77   static const char*
  78   fopen_mode(std::ios_base::openmode mode)
  79   {
  80     enum
  81       {
  82         in     = std::ios_base::in,
  83         out    = std::ios_base::out,
  84         trunc  = std::ios_base::trunc,
  85         app    = std::ios_base::app,
  86         binary = std::ios_base::binary
  87       };
  88
  89     switch (mode & (in|out|trunc|app|binary))
  90       {
  91       case (   out                 ): return "w";
  92       case (   out      |app       ): return "a";
  93       case (   out|trunc           ): return "w";
  94       case (in                     ): return "r";
  95       case (in|out                 ): return "r+";
  96       case (in|out|trunc           ): return "w+";
  97
  98       case (   out          |binary): return "wb";
  99       case (   out      |app|binary): return "ab";
 100       case (   out|trunc    |binary): return "wb";
 101       case (in              |binary): return "rb";
 102       case (in|out          |binary): return "r+b";
 103       case (in|out|trunc    |binary): return "w+b";
 104
 105       default: return 0; // invalid
 106       }
 107   }
 108 } // namespace __gnu_internal
 109
 110 namespace std
 111 {
 112   // Definitions for __basic_file<char>.
 113   __basic_file<char>::__basic_file(__c_lock* /*__lock*/)
 114   : _M_cfile(NULL), _M_cfile_created(false) { }
 115
 116   __basic_file<char>::~__basic_file()
 117   { this->close(); }
 118
 119   __basic_file<char>*
 120   __basic_file<char>::sys_open(__c_file* __file, ios_base::openmode)
 121   {
 122     __basic_file* __ret = NULL;
 123     if (!this->is_open() && __file)
 124       {
 125         _M_cfile = __file;
 126         _M_cfile_created = false;
 127         this->sync();
 128         __ret = this;
 129       }
 130     return __ret;
 131   }
 132
 133   __basic_file<char>*
 134   __basic_file<char>::sys_open(int __fd, ios_base::openmode __mode)
 135   {
 136     __basic_file* __ret = NULL;
 137     const char* __c_mode = __gnu_internal::fopen_mode(__mode);
 138     if (__c_mode && !this->is_open()
 139         && (_M_cfile = fdopen(__fd, __c_mode)))
 140       {
 141         _M_cfile_created = true;
 142         if (__fd == 0)
 143           setvbuf(_M_cfile, reinterpret_cast<char*>(NULL), _IONBF, 0);
 144         __ret = this;
 145       }
 146     return __ret;
 147   }
 148
 149   __basic_file<char>*
 150   __basic_file<char>::open(const char* __name, ios_base::openmode __mode,
 151                            int /*__prot*/)
 152   {
 153     __basic_file* __ret = NULL;
 154     const char* __c_mode = __gnu_internal::fopen_mode(__mode);
 155     if (__c_mode && !this->is_open())
 156       {
 157 #ifdef _GLIBCXX_USE_LFS
 158         if ((_M_cfile = fopen64(__name, __c_mode)))
 159 #else
 160         if ((_M_cfile = fopen(__name, __c_mode)))
 161 #endif
 162           {
 163             _M_cfile_created = true;
 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* __ret = static_cast<__basic_file*>(NULL);
 182     if (this->is_open())
 183       {
 184         if (_M_cfile_created)
 185           fclose(_M_cfile);
 186         else
 187           this->sync();
 188         _M_cfile = 0;
 189         __ret = this;
 190       }
 191     return __ret;
 192   }
 193
 194   streamsize
 195   __basic_file<char>::xsgetn(char* __s, streamsize __n)
 196   {
 197     streamsize __ret;
 198     do
 199       __ret = read(this->fd(), __s, __n);
 200     while (__ret == -1L && errno == EINTR);
 201     return __ret;
 202   }
 203
 204   streamsize
 205   __basic_file<char>::xsputn(const char* __s, streamsize __n)
 206   {
 207     streamsize __ret;
 208     do
 209       __ret = write(this->fd(), __s, __n);
 210     while (__ret == -1L && errno == EINTR);
 211     return __ret;
 212   }
 213
 214   streamsize
 215   __basic_file<char>::xsputn_2(const char* __s1, streamsize __n1,
 216                                const char* __s2, streamsize __n2)
 217   {
 218     streamsize __ret = 0;
 219 #ifdef _GLIBCXX_HAVE_WRITEV
 220     struct iovec __iov[2];
 221     __iov[0].iov_base = const_cast<char*>(__s1);
 222     __iov[0].iov_len = __n1;
 223     __iov[1].iov_base = const_cast<char*>(__s2);
 224     __iov[1].iov_len = __n2;
 225
 226     do
 227       __ret = writev(this->fd(), __iov, 2);
 228     while (__ret == -1L && errno == EINTR);
 229 #else
 230     if (__n1)
 231       do
 232         __ret = write(this->fd(), __s1, __n1);
 233       while (__ret == -1L && errno == EINTR);
 234
 235     if (__ret == __n1)
 236       {
 237         do
 238           __ret = write(this->fd(), __s2, __n2);
 239         while (__ret == -1L && errno == EINTR);
 240
 241         if (__ret != -1L)
 242           __ret += __n1;
 243       }
 244 #endif
 245     return __ret;
 246   }
 247
 248   streamoff
 249   __basic_file<char>::seekoff(streamoff __off, ios_base::seekdir __way)
 250   {
 251 #ifdef _GLIBCXX_USE_LFS
 252     return lseek64(this->fd(), __off, __way);
 253 #else
 254     if (__off > std::numeric_limits<off_t>::max()
 255         || __off < std::numeric_limits<off_t>::min())
 256       return -1L;
 257     return lseek(this->fd(), __off, __way);
 258 #endif
 259   }
 260
 261   int
 262   __basic_file<char>::sync()
 263   { return fflush(_M_cfile); }
 264
 265   streamsize
 266   __basic_file<char>::showmanyc()
 267   {
 268 #ifdef FIONREAD
 269     // Pipes and sockets.
 270 #ifdef _GLIBCXX_FIONREAD_TAKES_OFF_T
 271     off_t __num = 0;
 272 #else
 273     int __num = 0;
 274 #endif
 275     int __r = ioctl(this->fd(), FIONREAD, &__num);
 276     if (!__r && __num >= 0)
 277       return __num;
 278 #endif
 279
 280 #ifdef _GLIBCXX_HAVE_POLL
 281     // Cheap test.
 282     struct pollfd __pfd[1];
 283     __pfd[0].fd = this->fd();
 284     __pfd[0].events = POLLIN;
 285     if (poll(__pfd, 1, 0) <= 0)
 286       return 0;
 287 #endif
 288
 289 #if defined(_GLIBCXX_HAVE_S_ISREG) || defined(_GLIBCXX_HAVE_S_IFREG)
 290     // Regular files.
 291     struct stat __buffer;
 292     int __ret = fstat(this->fd(), &__buffer);
 293     if (!__ret && _GLIBCXX_ISREG(__buffer.st_mode))
 294         return __buffer.st_size - lseek(this->fd(), 0, ios_base::cur);
 295 #endif
 296     return 0;
 297   }
 298 }  // namespace std