four2eight.c

1 /* Jan. 2005.
2 
3    A utility that converts unformatted binary real data files
4    to unformatted binary double precision data files.
5 
6    Compile as 
7 
8         cc -o four2eight four2eight.c
9 
10    If you are running this on a little-endian platform
11    compile with -DSWAP like so:
12 
13         cc -o four2eight -DSWAP four2eight.c
14 
15    Use as 
16 
17         four2eight < RRTM_DATA > RRTM_DATA_DBL  (for example)
18 
19    JM
20 
21 */
22 
23 
24 #include <stdio.h>
25 
26 main()
27 {
28    int in, cr, cr1, n ;
29    int i ;
30    float x, x1 ;
31    double y, y1 ;
32 
33    while ( 
34      fread( &in, 1, 4, stdin ) > 0 ) {
35      swap4(&in, &cr) ;
36      n = cr ;
37      cr1 = 2*cr ;
38      fprintf(stderr, "%d > %d\n",cr,cr1) ;
39      swap4(&cr1,&cr) ;
40      fwrite( &cr, 1, 4, stdout ) ;
41      for ( i = 0 ; i < n ; i += 4 )
42      {
43        fread ( &x, 1, 4, stdin ) ;
44        swap4(&x,&x1) ;
45        y1 = x1 ;
46        swap8(&y1,&y) ;
47        fwrite ( &y, 1, 8, stdout ) ;
48      }
49      fread( &in, 1, 4, stdin ) ;
50      fwrite( &cr, 1, 4, stdout ) ;
51    }
52    fprintf(stderr,"\n") ;
53 }
54 
55 swap4( a, b )
56    char a[], b[] ;
57 {
58 #ifdef SWAP
59    b[0] = a[3] ;
60    b[1] = a[2] ;
61    b[2] = a[1] ;
62    b[3] = a[0] ;
63 #else
64    b[0] = a[0] ;
65    b[1] = a[1] ;
66    b[2] = a[2] ;
67    b[3] = a[3] ;
68 #endif
69 }
70 
71 swap8( a, b )
72    char a[], b[] ;
73 {
74 #ifdef SWAP
75    b[0] = a[7] ;
76    b[1] = a[6] ;
77    b[2] = a[5] ;
78    b[3] = a[4] ;
79    b[4] = a[3] ;
80    b[5] = a[2] ;
81    b[6] = a[1] ;
82    b[7] = a[0] ;
83 #else
84    b[0] = a[0] ;
85    b[1] = a[1] ;
86    b[2] = a[2] ;
87    b[3] = a[3] ;
88    b[4] = a[4] ;
89    b[5] = a[5] ;
90    b[6] = a[6] ;
91    b[7] = a[7] ;
92 #endif
93 }
94