1 /*
2 ** Try to enlarge an SQLite database by appending many unused pages.
3 ** The resulting database will fail PRAGMA integrity_check due to the
4 ** appended unused pages, but it should work otherwise.
5 **
6 ** Usage:
7 **
8 ** enlargedb DATABASE N
9 **
10 ** Adds N blank pages onto the end of DATABASE. N can be decimal
11 ** or hex. The total number of pages after adding must be no greater
12 ** than 4294967297
13 */
14 #include <stdio.h>
15 #include <string.h>
16 #include <stdlib.h>
17
main(int argc,char ** argv)18 int main(int argc, char **argv){
19 char *zEnd;
20 long long int toAppend;
21 long long int currentSz;
22 long long int newSz;
23 FILE *f;
24 size_t got;
25 int pgsz;
26 char zero = 0;
27 unsigned char buf[100];
28
29 if( argc!=3 ) goto usage_error;
30 toAppend = strtoll(argv[2], &zEnd, 0);
31 if( zEnd==argv[2] || zEnd[0] ) goto usage_error;
32 if( toAppend<1 ){
33 fprintf(stderr, "N must be at least 1\n");
34 exit(1);
35 }
36 f = fopen(argv[1], "r+b");
37 if( f==0 ){
38 fprintf(stderr, "cannot open \"%s\" for reading and writing\n", argv[1]);
39 exit(1);
40 }
41 got = fread(buf, 1, sizeof(buf), f);
42 if( got!=sizeof(buf) ) goto not_valid_db;
43 if( strcmp((char*)buf,"SQLite format 3")!=0 ) goto not_valid_db;
44 pgsz = (buf[16]<<8) + buf[17];
45 if( pgsz==1 ) pgsz = 65536;
46 if( pgsz<512 || pgsz>65536 || (pgsz&(pgsz-1))!=0 ) goto not_valid_db;
47 currentSz = (buf[28]<<24) + (buf[29]<<16) + (buf[30]<<8) + buf[31];
48 newSz = currentSz + toAppend;
49 if( newSz > 0xffffffff ) newSz = 0xffffffff;
50 buf[28] = (newSz>>24) & 0xff;
51 buf[29] = (newSz>>16) & 0xff;
52 buf[30] = (newSz>>8) & 0xff;
53 buf[31] = newSz & 0xff;
54 fseek(f, 28, SEEK_SET);
55 fwrite(&buf[28],4,1,f);
56 fseek(f, (long)(newSz*pgsz - 1), SEEK_SET);
57 fwrite(&zero,1,1,f);
58 fclose(f);
59 return 0;
60
61 not_valid_db:
62 fprintf(stderr,"not a valid database: %s\n", argv[1]);
63 exit(1);
64
65 usage_error:
66 fprintf(stderr,"Usage: %s DATABASE N\n", argv[0]);
67 exit(1);
68 }
69