libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/1-io.cc

   1 // 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
   2
   3 // Copyright (C) 2001-2024 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 // { dg-require-binary-io "" }
  24 // { dg-additional-files "seekoff-1io.tst" }
  25
  26 #include <fstream>
  27 #include <testsuite_hooks.h>
  28 #include <testsuite_io.h>
  29
  30 const char name_01[] = "seekoff-1io.tst";
  31
  32 void test05()
  33 {
  34   using namespace std;
  35   using namespace __gnu_test;
  36
  37   typedef filebuf::int_type     int_type;
  38   typedef filebuf::pos_type     pos_type;
  39   typedef filebuf::off_type     off_type;
  40
  41   streamsize                    strmsz_1;
  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   off_type off_1 = 0;
  50   off_type off_2 = 0;
  51
  52   // seekoff
  53   // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
  54   // alters the stream position to off
  55
  56   // in | out
  57   {
  58     constraint_filebuf fb;
  59     fb.open(name_01, ios_base::out | ios_base::in);
  60     VERIFY( !fb.write_position() );
  61     VERIFY( !fb.read_position() );
  62
  63     //beg
  64     strmsz_1 = fb.in_avail();
  65     pt_1 = fb.pubseekoff(2, ios_base::beg);
  66     fb.in_avail();
  67     off_1 = off_type(pt_1);
  68     VERIFY( off_1 > 0 );
  69     c1 = fb.snextc(); //current in pointer +1
  70     VERIFY( c1 == '9' );
  71     fb.pubseekoff(3, ios_base::beg);
  72     c2 = fb.sputc('\n');  //current in pointer +1
  73     fb.pubseekoff(4, ios_base::beg);
  74     c3 = fb.sgetc();
  75     VERIFY( c2 != c3 );
  76     VERIFY( c3 == '9' );
  77     fb.pubsync();
  78     c1 = fb.sgetc();
  79     VERIFY( c1 == c3 );
  80
  81     //cur
  82     pt_2 = fb.pubseekoff(2, ios_base::cur);
  83     off_2 = off_type(pt_2);
  84     VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
  85     c1 = fb.snextc(); //current in pointer +1
  86     VERIFY( c1 == '1' );
  87     fb.pubseekoff(0, ios_base::cur);
  88     c2 = fb.sputc('x');  //test current out pointer
  89     c3 = fb.sputc('\n');
  90     fb.pubseekoff(0, ios_base::cur);
  91     c1 = fb.sgetc();
  92     fb.pubsync();
  93     c3 = fb.sgetc();
  94     VERIFY( c1 == c3 );
  95
  96     //end
  97     pt_2 = fb.pubseekoff(0, ios_base::end);
  98     off_1 = off_type(pt_2);
  99     VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
 100     c3 = fb.sputc('\n');
 101     strmsz_1 = fb.sputn("because because because. . .", 28);
 102     VERIFY( strmsz_1 == 28 );
 103     fb.pubseekoff(-1, ios_base::end);
 104     fb.sgetc();
 105     c1 = fb.sungetc();
 106     // Defect?  retval of sungetc is not necessarily the character ungotten.
 107     // So re-get it.
 108     c1 = fb.sgetc();
 109     fb.pubsync();
 110     c3 = fb.sgetc();
 111     VERIFY( c1 == c3 );
 112     VERIFY( !fb.write_position() );
 113     VERIFY( fb.read_position() );
 114   }
 115 }
 116
 117 int main()
 118 {
 119   test05();
 120   return 0;
 121 }