libstdc++-v3/testsuite/27_io/basic_filebuf/seekpos/char/1-in.cc

   1 // 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
   2
   3 // Copyright (C) 2001-2023 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 3, 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 COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 27.8.1.4 Overridden virtual functions
  21
  22 // { dg-require-fileio "" }
  23
  24 #include <fstream>
  25 #include <testsuite_hooks.h>
  26 #include <testsuite_io.h>
  27
  28 // @require@ %-*.tst %-*.txt
  29 // @diff@ %-*.tst %*.txt
  30
  31 const char name_01[] = "seekpos.txt"; // file with data in it
  32
  33 void test05()
  34 {
  35   using namespace std;
  36   using namespace __gnu_test;
  37
  38   typedef filebuf::int_type     int_type;
  39   typedef filebuf::pos_type     pos_type;
  40   typedef filebuf::off_type     off_type;
  41   typedef filebuf::traits_type  traits_type;
  42
  43   int_type c1;
  44   int_type c2;
  45   int_type c3;
  46
  47   pos_type pt_1(off_type(-1));
  48   pos_type pt_2(off_type(0));
  49   pos_type pt_3;
  50   off_type off_1 = 0;
  51   off_type off_2 = 0;
  52
  53   // seekpos
  54   // pubseekpos(pos_type sp, ios_base::openmode)
  55   // alters the stream position to sp
  56
  57   // in
  58   {
  59     constraint_filebuf fb;
  60     fb.open(name_01, ios_base::in);
  61     VERIFY( !fb.write_position() );
  62
  63     // beg
  64     pt_1 = fb.pubseekoff(78, ios_base::beg);
  65     off_1 = off_type(pt_1);
  66     VERIFY( off_1 > 0 );
  67     c1 = fb.snextc(); //current in pointer +1
  68     VERIFY( c1 == 't' );
  69
  70     // cur
  71     pt_3 = fb.pubseekoff(0, ios_base::cur);
  72     fb.pubseekpos(pt_3);
  73     c2 = fb.sputc('\n'); //test current out pointer
  74     pt_3 = fb.pubseekoff(0, ios_base::cur);
  75     fb.pubseekpos(pt_3);
  76     c3 = fb.sgetc();
  77     fb.pubsync(); //resets pointers
  78     pt_2 = fb.pubseekpos(pt_1);
  79     off_2 = off_type(pt_2);
  80     VERIFY( off_1 == off_2 );
  81     c3 = fb.snextc(); //current in pointer +1
  82     VERIFY( c2 == traits_type::eof() );
  83     VERIFY( c2 != c3 );
  84
  85     // end
  86     pt_1 = fb.pubseekoff(0, ios_base::end);
  87     off_1 = off_type(pt_1);
  88     VERIFY( off_1 > off_2 );
  89     fb.sputn("\nof the wonderful things he does!!\nok", 37);
  90     fb.pubsync();
  91     VERIFY( !fb.write_position() );
  92     fb.close();
  93     VERIFY( !fb.is_open() );
  94   }
  95 }
  96
  97 int main()
  98 {
  99   test05();
 100   return 0;
 101 }