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 (void)(argc); /* Unused parameter */ 36 zName = (const char*)sqlite3_value_text(argv[0]); 37 if( zName==0 ) return; 38 in = fopen(zName, "rb"); 39 if( in==0 ) return; 40 fseek(in, 0, SEEK_END); 41 nIn = ftell(in); 42 rewind(in); 43 pBuf = sqlite3_malloc( nIn ); 44 if( pBuf && 1==fread(pBuf, nIn, 1, in) ){ 45 sqlite3_result_blob(context, pBuf, nIn, sqlite3_free); 46 }else{ 47 sqlite3_free(pBuf); 48 } 49 fclose(in); 50 } 51 52 /* 53 ** Implementation of the "writefile(X,Y)" SQL function. The argument Y 54 ** is written into file X. The number of bytes written is returned. Or 55 ** NULL is returned if something goes wrong, such as being unable to open 56 ** file X for writing. 57 */ 58 static void writefileFunc( 59 sqlite3_context *context, 60 int argc, 61 sqlite3_value **argv 62 ){ 63 FILE *out; 64 const char *z; 65 sqlite3_int64 rc; 66 const char *zFile; 67 68 (void)(argc); /* Unused parameter */ 69 zFile = (const char*)sqlite3_value_text(argv[0]); 70 if( zFile==0 ) return; 71 out = fopen(zFile, "wb"); 72 if( out==0 ) return; 73 z = (const char*)sqlite3_value_blob(argv[1]); 74 if( z==0 ){ 75 rc = 0; 76 }else{ 77 rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out); 78 } 79 fclose(out); 80 sqlite3_result_int64(context, rc); 81 } 82 83 84 #ifdef _WIN32 85 __declspec(dllexport) 86 #endif 87 int sqlite3_fileio_init( 88 sqlite3 *db, 89 char **pzErrMsg, 90 const sqlite3_api_routines *pApi 91 ){ 92 int rc = SQLITE_OK; 93 SQLITE_EXTENSION_INIT2(pApi); 94 (void)pzErrMsg; /* Unused parameter */ 95 rc = sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0, 96 readfileFunc, 0, 0); 97 if( rc==SQLITE_OK ){ 98 rc = sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0, 99 writefileFunc, 0, 0); 100 } 101 return rc; 102 } 103