2-io.cc

Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

// 2001-05-21 Benjamin Kosnik  <[e-mail]>

// Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// 27.8.1.4 Overridden virtual functions

#include <fstream>
#include <testsuite_hooks.h>
#include <testsuite_io.h>

// @require@ %-*.tst %-*.txt
// @diff@ %-*.tst %*.txt

const char name_01[] = "seekpos-2io.tst"; // file with data in it

void test05() 
{
  using namespace std;
  using namespace __gnu_test;

  typedef filebuf::int_type 	int_type;
  typedef filebuf::pos_type 	pos_type;
  typedef filebuf::off_type 	off_type;

  bool test __attribute__((unused)) = true;

  int_type c1;
  int_type c2;
  int_type c3;

  pos_type pt_1(off_type(-1));
  pos_type pt_2(off_type(0));
  pos_type pt_3;
  off_type off_1 = 0;
  off_type off_2 = 0;

  // seekpos
  // pubseekpos(pos_type sp, ios_base::openmode)
  // alters the stream position to sp

  // in | out
  {
    constraint_filebuf fb;
    fb.pubsetbuf(0, 0);
    fb.open(name_01, ios_base::out | ios_base::in);
    VERIFY( fb.unbuffered() );

    // beg
    pt_1 = fb.pubseekoff(78, ios_base::beg);
    off_1 = off_type(pt_1);
    VERIFY( off_1 > 0 );
    c1 = fb.snextc(); //current in pointer +1
    VERIFY( c1 == 't' );

    // cur
    pt_3 = fb.pubseekoff(0, ios_base::cur);
    fb.pubseekpos(pt_3);
    c2 = fb.sputc('\n'); //test current out pointer
    pt_3 = fb.pubseekoff(0, ios_base::cur);
    fb.pubseekpos(pt_3);
    c3 = fb.sgetc();
    fb.pubsync(); //resets pointers
    pt_2 = fb.pubseekpos(pt_1);
    off_2 = off_type(pt_2);
    VERIFY( off_1 == off_2 );
    c3 = fb.snextc(); //current in pointer +1
    VERIFY( c2 == c3 );

    // end
    pt_1 = fb.pubseekoff(0, ios_base::end);
    off_1 = off_type(pt_1);
    VERIFY( off_1 > off_2 );
    fb.sputn("\nof the wonderful things he does!!\nok", 37);
    fb.pubsync();
    VERIFY( fb.unbuffered() );
    fb.close();
    VERIFY( !fb.is_open() );
  }
}

int main() 
{
  test05();
  return 0;
}