libstdc++-v3/testsuite/27_io/objects/char/9661-1.cc

   1 // { dg-require-fork "" }
   2 // { dg-require-mkfifo "" }
   3
   4 // 2003-04-30  Petur Runolfsson <peturr02@ru.is>
   5
   6 // Copyright (C) 2003-2016 Free Software Foundation, Inc.
   7 //
   8 // This file is part of the GNU ISO C++ Library.  This library is free
   9 // software; you can redistribute it and/or modify it under the
  10 // terms of the GNU General Public License as published by the
  11 // Free Software Foundation; either version 3, or (at your option)
  12 // any later version.
  13
  14 // This library is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License along
  20 // with this library; see the file COPYING3.  If not see
  21 // <http://www.gnu.org/licenses/>.
  22
  23 // No asserts, avoid leaking the semaphores if a VERIFY fails.
  24 #undef _GLIBCXX_ASSERT
  25
  26 #include <testsuite_hooks.h>
  27 #include <cstdio>
  28 #include <cstdlib>
  29 #include <iostream>
  30 #include <unistd.h>
  31 #include <signal.h>
  32 #include <fcntl.h>
  33 #include <sys/types.h>
  34 #include <sys/stat.h>
  35
  36 // Check that cin.rdbuf()->sputbackc() puts characters back to stdin.
  37 // If cin.rdbuf() is a filebuf, this succeeds when stdin is a regular
  38 // file, but fails otherwise, hence the named fifo.
  39 bool test01()
  40 {
  41   using namespace std;
  42   using namespace __gnu_test;
  43
  44   bool test __attribute__((unused)) = true;
  45
  46   const char* name = "tmp_fifo5";
  47
  48   signal(SIGPIPE, SIG_IGN);
  49
  50   unlink(name);
  51   mkfifo(name, S_IRWXU);
  52   semaphore s1, s2;
  53
  54   int child = fork();
  55   VERIFY( child != -1 );
  56
  57   if (child == 0)
  58     {
  59       FILE* file = fopen(name, "r+");
  60       VERIFY( file != 0 );
  61       fputs("Whatever\n", file);
  62       fflush(file);
  63       s1.signal();
  64       s2.wait();
  65       fclose(file);
  66       s1.signal();
  67       exit(0);
  68     }
  69
  70   VERIFY( freopen(name, "r", stdin) );
  71   s1.wait();
  72
  73   int c1 = fgetc(stdin);
  74   VERIFY( c1 != EOF );
  75   int c2 = cin.rdbuf()->sputbackc('a');
  76   VERIFY( c2 != EOF );
  77   VERIFY( c2 == 'a' );
  78
  79   int c3 = fgetc(stdin);
  80   VERIFY( c3 != EOF );
  81   VERIFY( c3 == c2 );
  82   int c4 = ungetc('b', stdin);
  83   VERIFY( c4 != EOF );
  84   VERIFY( c4 == 'b' );
  85
  86   int c5 = cin.rdbuf()->sgetc();
  87   VERIFY( c5 != EOF );
  88   VERIFY( c5 == c4 );
  89   s2.signal();
  90   s1.wait();
  91
  92   return test;
  93 }
  94
  95 int main()
  96 {
  97   return !test01();
  98 }