We have a new format between the former version 1 and 2. So shift version numbers. Add README

1 files changed, 70 insertions, 0 deletions

diff --git a/src/export/extract_version_4.c b/src/export/extract_version_4.c
new file mode 100644
index 0000000..e0e858d
--- /dev/null
+++ b/src/export/extract_version_4.c
@@ -0,0 +1,70 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <zlib.h>
+#include "mystdlib.h"
+
+#define XORLEN (29)
+#define HUGEBLOCK (8*1024*1024)
+
+int main(int argc, char **argv) {
+  unsigned const char xorkey [XORLEN] = "Just for Fun. Linus Torvalds.";
+  unsigned char input  [XORLEN];
+  unsigned char output [HUGEBLOCK];
+  char respath[32]; /* file_XXXXX\0 */
+  int zres = 0, filenum = 0, resfile;
+  size_t i, offs = 0, reported = 0;
+  MAP in;
+
+  if( argc != 2 ) exit(111);
+  in = map_file( argv[1], 1 );
+
+  z_stream z; memset( &z, 0, sizeof(z));
+
+  while( offs < in->size ) {
+    size_t inlen = offs + XORLEN < in->size ? XORLEN : in->size - offs;
+    for( i=0; i<inlen; ++i ) input[i] = in->addr[offs+i] ^ xorkey[i];
+    z.next_in  = input;  z.avail_in = inlen;
+    z.next_out = output; z.avail_out = HUGEBLOCK;
+    inflateInit( &z ); zres = inflate( &z, Z_NO_FLUSH );
+    if( (zres != Z_OK) && (zres != Z_STREAM_END) )
+      goto error_continue;
+
+    z.next_in  = in->addr + offs + inlen;
+    z.avail_in = (unsigned int)(in->size - offs - inlen);
+    while( zres == Z_OK ) zres = inflate( &z, Z_NO_FLUSH );
+
+    if( zres != Z_STREAM_END ) {
+error_continue:
+      inflateEnd(&z); memset( &z, 0, sizeof(z));
+      offs++;
+      continue;
+    }
+
+    sprintf( respath, "file_%05X", filenum++ );
+
+    resfile = open( respath, O_RDWR | O_CREAT, 0644 );
+    if( resfile < 0 ) {
+      fprintf( stderr, "Could not open output file %s\n", respath );
+      exit(1);
+    }
+    write( resfile, output, z.total_out );
+    close( resfile );
+    offs += z.total_in;
+
+    if( reported < ( offs * 10 ) / in->size ) {
+      reported++;
+      printf( "%zd%% ", 10 * reported );
+      fflush( stdout );
+    }
+
+    inflateEnd(&z); memset( &z, 0, sizeof(z));
+  }
+  unmap_file(&in);
+  if( reported < 10 )
+    printf( "100%% " );
+  fflush( stdout );
+  return 0;
+}