LORENE
fread_be.C
1 /*
2  * Read binary data from a file according to the Big Endian convention
3  *
4  */
5 
6 /*
7  * Copyright (c) 2001 Eric Gourgoulhon
8  *
9  * This file is part of LORENE.
10  *
11  * LORENE is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * LORENE is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License
22  * along with LORENE; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24  *
25  */
26 
27 char fread_be_C[] = "$Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/fread_be.C,v 1.6 2014/10/13 08:53:32 j_novak Exp $" ;
28 
29 /*
30  * $Id: fread_be.C,v 1.6 2014/10/13 08:53:32 j_novak Exp $
31  * $Log: fread_be.C,v $
32  * Revision 1.6 2014/10/13 08:53:32 j_novak
33  * Lorene classes and functions now belong to the namespace Lorene.
34  *
35  * Revision 1.5 2014/10/06 15:16:11 j_novak
36  * Modified #include directives to use c++ syntax.
37  *
38  * Revision 1.4 2009/01/19 15:23:17 j_novak
39  * Change of some casts to avoid warnings
40  *
41  * Revision 1.3 2008/08/19 06:42:01 j_novak
42  * Minor modifications to avoid warnings with gcc 4.3. Most of them concern
43  * cast-type operations, and constant strings that must be defined as const char*
44  *
45  * Revision 1.2 2001/12/13 15:01:19 e_gourgoulhon
46  * Array bytes_big now created with a new char[]
47  *
48  * Revision 1.1 2001/12/04 21:32:39 e_gourgoulhon
49  * Functions similar to the stdio fread/fwrite except that they ensure
50  * the big endian convention, whatever the system convention is.
51  *
52  * Revision 1.1 2001/11/23 15:09:09 e_gourgoulhon
53  * Templates for new source files
54  *
55  *
56  * $Header: /cvsroot/Lorene/C++/Source/Non_class_members/Utilities/fread_be.C,v 1.6 2014/10/13 08:53:32 j_novak Exp $
57  *
58  */
59 
60 // C headers
61 #include <cstdio>
62 #include <cassert>
63 
64  //-------------------------//
65  // int version //
66  //-------------------------//
67 
68 namespace Lorene {
69 int fread_be(int* aa, int size, int nb, FILE* fich) {
70 
71  assert(size == 4) ;
72 
73  // Determines whether the default storage is big endian
74  // or large endians
75 
76  int itest = 1 ;
77  bool little_endian = ( *( reinterpret_cast<char*>(&itest) ) == 1) ;
78 
79  if (little_endian) {
80 
81  int size_tot = 4 * nb ;
82 
83  char* bytes_big = new char[size_tot] ;
84 
85  int nr = int(fread(bytes_big, 1, size_tot, fich)) ;
86 
87  char* pbig = bytes_big ;
88  char* plit = reinterpret_cast<char*>( aa );
89 
90  for (int j=0; j< nb; j++) {
91 
92  for (int i=0; i<4; i++) {
93  plit[i] = pbig[3-i] ;
94  }
95 
96  plit += 4 ; // next item
97  pbig += 4 ;
98 
99  }
100 
101  delete [] bytes_big ;
102 
103  return nr / 4 ;
104 
105  }
106  else { // Big endian case: nothing to do:
107 
108  return int(fread(aa, size, nb, fich)) ;
109  }
110 
111 }
112 
113  //-------------------------//
114  // double version //
115  //-------------------------//
116 
117 int fread_be(double* aa, int size, int nb, FILE* fich) {
118 
119  assert(size == 8) ;
120 
121  // Determines whether the default storage is big endian
122  // or large endians
123 
124  int itest = 1 ;
125  bool little_endian = ( *( reinterpret_cast<char*>(&itest) ) == 1) ;
126 
127  if (little_endian) {
128 
129  int size_tot = 8 * nb ;
130 
131  char* bytes_big = new char[size_tot] ;
132 
133  int nr = int(fread(bytes_big, 1, size_tot, fich)) ;
134 
135  char* pbig = bytes_big ;
136  char* plit = reinterpret_cast<char*>( aa );
137 
138  for (int j=0; j< nb; j++) {
139 
140  for (int i=0; i<8; i++) {
141  plit[i] = pbig[7-i] ;
142  }
143 
144  plit += 8 ; // next item
145  pbig += 8 ;
146 
147  }
148 
149  delete [] bytes_big ;
150 
151  return nr / 8 ;
152 
153  }
154  else { // Big endian case: nothing to do:
155 
156  return int(fread(aa, size, nb, fich)) ;
157  }
158 
159 }
160 
161 }
int fread_be(int *aa, int size, int nb, FILE *fich)
Reads integer(s) from a binary file according to the big endian convention.
Definition: fread_be.C:69
Lorene prototypes.
Definition: app_hor.h:64