1 /* 2 ** 2014-06-13 3 ** 4 ** The author disclaims copyright to this source code. In place of 5 ** a legal notice, here is a blessing: 6 ** 7 ** May you do good and not evil. 8 ** May you find forgiveness for yourself and forgive others. 9 ** May you share freely, never taking more than you give. 10 ** 11 ****************************************************************************** 12 ** 13 ** This SQLite extension implements SQL functions readfile() and 14 ** writefile(). 15 */ 16 #include "sqlite3ext.h" 17 SQLITE_EXTENSION_INIT1 18 #include <stdio.h> 19 20 /* 21 ** Implementation of the "readfile(X)" SQL function. The entire content 22 ** of the file named X is read and returned as a BLOB. NULL is returned 23 ** if the file does not exist or is unreadable. 24 */ 25 static void readfileFunc( 26 sqlite3_context *context, 27 int argc, 28 sqlite3_value **argv 29 ){ 30 const char *zName; 31 FILE *in; 32 long nIn; 33 void *pBuf; 34 35 zName = (const char*)sqlite3_value_text(argv[0]); 36 if( zName==0 ) return; 37 in = fopen(zName, "rb"); 38 if( in==0 ) return; 39 fseek(in, 0, SEEK_END); 40 nIn = ftell(in); 41 rewind(in); 42 pBuf = sqlite3_malloc( nIn ); 43 if( pBuf && 1==fread(pBuf, nIn, 1, in) ){ 44 sqlite3_result_blob(context, pBuf, nIn, sqlite3_free); 45 }else{ 46 sqlite3_free(pBuf); 47 } 48 fclose(in); 49 } 50 51 /* 52 ** Implementation of the "writefile(X,Y)" SQL function. The argument Y 53 ** is written into file X. The number of bytes written is returned. Or 54 ** NULL is returned if something goes wrong, such as being unable to open 55 ** file X for writing. 56 */ 57 static void writefileFunc( 58 sqlite3_context *context, 59 int argc, 60 sqlite3_value **argv 61 ){ 62 FILE *out; 63 const char *z; 64 sqlite3_int64 rc; 65 const char *zFile; 66 67 zFile = (const char*)sqlite3_value_text(argv[0]); 68 if( zFile==0 ) return; 69 out = fopen(zFile, "wb"); 70 if( out==0 ) return; 71 z = (const char*)sqlite3_value_blob(argv[1]); 72 if( z==0 ){ 73 rc = 0; 74 }else{ 75 rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out); 76 } 77 fclose(out); 78 sqlite3_result_int64(context, rc); 79 } 80 81 82 #ifdef _WIN32 83 __declspec(dllexport) 84 #endif 85 int sqlite3_fileio_init( 86 sqlite3 *db, 87 char **pzErrMsg, 88 const sqlite3_api_routines *pApi 89 ){ 90 int rc = SQLITE_OK; 91 SQLITE_EXTENSION_INIT2(pApi); 92 (void)pzErrMsg; /* Unused parameter */ 93 rc = sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0, 94 readfileFunc, 0, 0); 95 if( rc==SQLITE_OK ){ 96 rc = sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0, 97 writefileFunc, 0, 0); 98 } 99 return rc; 100 } 101