1 /*****************************************************************************
2    Major portions of this software are copyrighted by the Medical College
3    of Wisconsin, 1994-2000, and are released under the Gnu General Public
4    License, Version 2.  See the file README.Copyright for details.
5 ******************************************************************************/
6 
7 #include <stdio.h>
8 #include <unistd.h>
9 #include "mrilib.h"
10 
11 typedef struct { unsigned char a,b,c,d ; } fourbytes ;
12 
13 #define TEMP_FILE "Frodo.Lives"
14 #define BUFSIZE   64000
15 
16 static byte bbuf[BUFSIZE] ;
17 
18 #define MAXPAT 256
19 
main(int argc,char * argv[])20 int main( int argc , char * argv[] )
21 {
22    FILE * infil , * outfil ;
23    int narg , nbyte , nbyt , quiet = 0 , ndone ;
24    int npat,ipat,jpat,ii,typ,len,num , cpat_len ;
25    int pattype[MAXPAT] , patsize[MAXPAT] ;
26    char * cpat = NULL ;
27 
28    if( argc < 2 || strncmp(argv[1],"-help",2) == 0 ){
29      printf("Usage: 24swap [options] file ...\n"
30             "Swaps bytes pairs and/or quadruples on the files listed.\n"
31             "Options:\n"
32             " -q            Operate quietly\n"
33             " -pattern pat  'pat' determines the pattern of 2 and 4\n"
34             "                 byte swaps.  Each element is of the form\n"
35             "                 2xN or 4xN, where N is the number of\n"
36             "                 bytes to swap as pairs (for 2x) or\n"
37             "                 as quadruples (for 4x).  For 2x, N must\n"
38             "                 be divisible by 2; for 4x, N must be\n"
39             "                 divisible by 4.  The whole pattern is\n"
40             "                 made up of elements separated by colons,\n"
41             "                 as in '-pattern 4x39984:2x0'.  If bytes\n"
42             "                 are left over after the pattern is used\n"
43             "                 up, the pattern starts over.  However,\n"
44             "                 if a byte count N is zero, as in the\n"
45             "                 example below, then it means to continue\n"
46             "                 until the end of file.\n"
47             "\n"
48             " N.B.: You can also use 1xN as a pattern, indicating to\n"
49             "         skip N bytes without any swapping.\n"
50             " N.B.: A default pattern can be stored in the Unix\n"
51             "         environment variable AFNI_24SWAP_PATTERN.\n"
52             "         If no -pattern option is given, the default\n"
53             "         will be used.  If there is no default, then\n"
54             "         nothing will be done.\n"
55             " N.B.: If there are bytes 'left over' at the end of the file,\n"
56             "         they are written out unswapped.  This will happen\n"
57             "         if the file is an odd number of bytes long.\n"
58             " N.B.: If you just want to swap pairs, see program 2swap.\n"
59             "         For quadruples only, see program 4swap.\n"
60             " N.B.: This program will overwrite the input file!\n"
61             "         You might want to test it first.\n"
62             "\n"
63             " Example: 24swap -pat 4x8:2x0 fred\n"
64             "          If fred contains 'abcdabcdabcdabcdabcd' on input,\n"
65             "          then fred has    'dcbadcbabadcbadcbadc' on output.\n"
66          ) ;
67      exit(0) ;
68    }
69 
70    machdep() ;
71 
72    /*-- scan arguments --*/
73 
74    narg = 1 ;
75 
76    while( narg < argc && argv[narg][0] == '-' ){
77 
78       if( strncmp(argv[narg],"-q",2) == 0 ){
79          quiet = 1 ; narg++ ; continue ;
80       }
81 
82       if( strncmp(argv[narg],"-pat",4) == 0 ){
83          cpat = argv[++narg] ; narg++ ; continue ;
84       }
85 
86       fprintf(stderr,"** 24swap: Unknown option %s\n",argv[narg]) ;
87       exit(1) ;
88    }
89 
90    if( narg == argc ){
91      fprintf(stderr,"** 24swap: No input files?\n") ; exit(1) ;
92    }
93 
94    if( cpat == NULL ) cpat = getenv("AFNI_24SWAP_PATTERN") ;
95    if( cpat == NULL ){
96      fprintf(stderr,"** 24swap: No pattern?  Exiting!\n") ; exit(1) ;
97    }
98    cpat_len = strlen(cpat) ;
99    if( cpat_len < 3 ){
100      fprintf(stderr,"** 24swap: Stupid pattern?  Exiting!\n") ; exit(1) ;
101    }
102 
103    /*-- parse cpat --*/
104 
105    ipat = npat = 0 ; cpat_len = strlen(cpat) ;
106    while( ipat < cpat_len ){
107       ii = sscanf( cpat+ipat , "%dx%d%n" , &typ,&len,&num ) ;
108       if( ii <= 0 ) break ;
109       if( ii != 2 ){
110          fprintf(stderr,"** 24swap: illegal pattern %s\n",cpat); exit(1);
111       }
112       if( len < 0 || (typ!=2 && typ!=4 && typ!=1 ) ){
113          fprintf(stderr,"** 24swap: illegal pattern %s\n",cpat); exit(1);
114       }
115       if( typ == 2 && len%2 != 0 ){
116          fprintf(stderr,"** 24swap: illegal pattern %s\n",cpat); exit(1);
117       }
118       if( typ == 4 && len%4 != 0 ){
119          fprintf(stderr,"** 24swap: illegal pattern %s\n",cpat); exit(1);
120       }
121 
122       pattype[npat] = typ ;
123       patsize[npat] = len ;
124       npat++ ; ipat += num+1 ;
125    }
126 
127    if( npat < 1 ){
128       fprintf(stderr,"** 24swap: illegal pattern %s\n",cpat); exit(1);
129    }
130 
131    /*-- loop over files --*/
132 
133    for( ; narg < argc ; narg++ ){
134       infil = fopen( argv[narg] , "r" ) ;
135       if( infil == NULL ){
136          fprintf(stderr,"** 24swap: File %s not found - skipping it!\n",argv[narg]);
137          continue ;
138       }
139 
140       if( !quiet){ printf("-- opened %s",argv[narg]) ; fflush(stdout) ; }
141 
142       outfil = fopen( TEMP_FILE , "w" ) ;
143       if( outfil == NULL ){
144          printf("** 24swap: Cannot open temporary file - exiting!\n"); exit(1);
145       }
146 
147       ndone = 0 ; ipat = 0 ;  /* loop over patterns and execute them */
148       while(1){
149 
150          if( patsize[ipat] == 0 ){  /* do rest of file this way */
151             while(1){
152                nbyt = fread( bbuf , sizeof(byte) , BUFSIZE , infil ) ;
153                if( nbyt <= 0 ) break ;  /* end of file */
154                switch( pattype[ipat] ){
155                   case 1: /* nothing to do */             ; break ;
156                   case 2: swap_twobytes ( nbyt/2 , bbuf ) ; break ;
157                   case 4: swap_fourbytes( nbyt/4 , bbuf ) ; break ;
158                }
159                fwrite( bbuf , sizeof(byte) , nbyt , outfil ) ;
160                ndone += nbyt ;
161                if( !quiet && ndone > 1000000 ){
162                   ndone -= 1000000 ; printf(".") ; fflush(stdout) ;
163                }
164             }
165             break ; /* to end of outer loop */
166 
167          } else {                   /* do patsize[ipat] bytes */
168             ii = 0 ;
169             while(1){
170                jpat = MIN( patsize[ipat] - ii , BUFSIZE ) ;
171                nbyt = fread( bbuf , sizeof(byte) , jpat , infil ) ;
172                if( nbyt <= 0 ) break ;  /* end of file */
173                switch( pattype[ipat] ){
174                   case 1: /* nothing to do */             ; break ;
175                   case 2: swap_twobytes ( nbyt/2 , bbuf ) ; break ;
176                   case 4: swap_fourbytes( nbyt/4 , bbuf ) ; break ;
177                }
178                fwrite( bbuf , sizeof(byte) , nbyt , outfil ) ;
179                ndone += nbyt ;
180                if( !quiet && ndone > 1000000 ){
181                   ndone -= 1000000 ; printf(".") ; fflush(stdout) ;
182                }
183                ii += nbyt ; if( ii >= patsize[ipat] ) break ;
184             }
185          }
186 
187          if( nbyt <= 0 ) break ; /* to end of outer loop */
188 
189          ipat++ ; if( ipat >= npat ) ipat = 0 ;  /* continue outer loop */
190 
191       } /* end of outer loop */
192 
193       fsync(fileno(outfil)) ; fclose(infil) ; fclose(outfil) ;
194 
195       unlink( argv[narg] ) ;
196       rename( TEMP_FILE , argv[narg] ) ;
197 
198       if( !quiet ){ printf(".\n") ; fflush(stdout) ; }
199    }
200    exit(0) ;
201 }
202