1 //Copyright (c) 2006-2009 Emil Dotchevski and Reverge Studios, Inc.
2
3 //Distributed under the Boost Software License, Version 1.0. (See accompanying
4 //file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6 //This example demonstrates the intended use of various commonly used
7 //error_info typedefs provided by Boost Exception.
8
9 #include <boost/exception/errinfo_api_function.hpp>
10 #include <boost/exception/errinfo_at_line.hpp>
11 #include <boost/exception/errinfo_errno.hpp>
12 #include <boost/exception/errinfo_file_handle.hpp>
13 #include <boost/exception/errinfo_file_name.hpp>
14 #include <boost/exception/errinfo_file_open_mode.hpp>
15 #include <boost/exception/info.hpp>
16 #include <boost/throw_exception.hpp>
17 #include <boost/shared_ptr.hpp>
18 #include <boost/weak_ptr.hpp>
19 #include <stdio.h>
20 #include <errno.h>
21 #include <exception>
22
23 struct error : virtual std::exception, virtual boost::exception { };
24 struct file_error : virtual error { };
25 struct file_open_error: virtual file_error { };
26 struct file_read_error: virtual file_error { };
27
28 boost::shared_ptr<FILE>
open_file(char const * file,char const * mode)29 open_file( char const * file, char const * mode )
30 {
31 if( FILE * f=fopen(file,mode) )
32 return boost::shared_ptr<FILE>(f,fclose);
33 else
34 BOOST_THROW_EXCEPTION(
35 file_open_error() <<
36 boost::errinfo_api_function("fopen") <<
37 boost::errinfo_errno(errno) <<
38 boost::errinfo_file_name(file) <<
39 boost::errinfo_file_open_mode(mode) );
40 }
41
42 size_t
read_file(boost::shared_ptr<FILE> const & f,void * buf,size_t size)43 read_file( boost::shared_ptr<FILE> const & f, void * buf, size_t size )
44 {
45 size_t nr=fread(buf,1,size,f.get());
46 if( ferror(f.get()) )
47 BOOST_THROW_EXCEPTION(
48 file_read_error() <<
49 boost::errinfo_api_function("fread") <<
50 boost::errinfo_errno(errno) <<
51 boost::errinfo_file_handle(f) );
52 return nr;
53 }
54