libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/4.cc

   1 // { dg-require-fileio "" }
   2
   3 // Copyright (C) 2010-2024 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 #include <fstream>
  23 #include <cstring>
  24 #include <testsuite_hooks.h>
  25
  26 void test01()
  27 {
  28   using namespace std;
  29
  30   typedef filebuf::pos_type pos_type;
  31   const char name[] = "tmp_seekoff-4.tst";
  32
  33   const size_t size = 12;
  34   char buf[size];
  35   streamsize n;
  36
  37   filebuf fb;
  38   fb.open(name, ios_base::in | ios_base::out | ios_base::trunc);
  39
  40   n = fb.sputn("abcd", 4);
  41   VERIFY( n == 4 );
  42
  43   fb.pubseekoff(0, ios_base::beg);
  44   n = fb.sgetn(buf, 3);
  45   VERIFY( n == 3 );
  46   VERIFY( !memcmp(buf, "abc", 3) );
  47
  48   // Check read => write without pubseekoff(0, ios_base::cur)
  49
  50   n = fb.sputn("ef", 2);
  51   VERIFY( n == 2 );
  52
  53   fb.pubseekoff(0, ios_base::beg);
  54
  55   n = fb.sgetn(buf, size);
  56   VERIFY( n == 5 );
  57   VERIFY( !memcmp(buf, "abcef", 5) );
  58
  59   fb.pubseekoff(0, ios_base::beg);
  60   n = fb.sputn("gh", 2);
  61   VERIFY( n == 2 );
  62
  63   // Check write => read without pubseekoff(0, ios_base::cur)
  64
  65   n = fb.sgetn( buf, 3 );
  66   VERIFY( !memcmp(buf, "cef", 3) );
  67
  68   n = fb.sputn("ijkl", 4);
  69   VERIFY( n == 4 );
  70
  71   fb.pubseekoff(0, ios_base::beg);
  72   n = fb.sgetn(buf, 2);
  73   VERIFY( n == 2 );
  74   VERIFY( !memcmp(buf, "gh", 2) );
  75
  76   fb.pubseekoff(0, ios_base::end);
  77   n = fb.sputn("mno", 3);
  78   VERIFY( n == 3 );
  79
  80   fb.pubseekoff(0, ios_base::beg);
  81   n = fb.sgetn(buf, size);
  82   VERIFY( n == 12 );
  83   VERIFY( !memcmp(buf, "ghcefijklmno", 12) );
  84
  85   fb.close();
  86 }
  87
  88 int main()
  89 {
  90   test01();
  91   return 0;
  92 }