Index: src/shell.c
==================================================================
--- src/shell.c
+++ src/shell.c
@@ -432,10 +432,11 @@
   struct previous_mode_data explainPrev;
                          /* Holds the mode information just before
                          ** .explain ON */
   char outfile[FILENAME_MAX]; /* Filename for *out */
   const char *zDbFilename;    /* name of the database file */
+  char *zFreeOnClose;         /* Filename to free when closing */
   const char *zVfs;           /* Name of VFS to use */
   sqlite3_stmt *pStmt;   /* Current statement if any. */
   FILE *pLog;            /* Write log output here */
 };
 
@@ -1414,10 +1415,11 @@
   "                         line     One value per line\n"
   "                         list     Values delimited by .separator string\n"
   "                         tabs     Tab-separated values\n"
   "                         tcl      TCL list elements\n"
   ".nullvalue STRING      Print STRING in place of NULL values\n"
+  ".open ?FILENAME?       Close existing database and reopen FILENAME\n"
   ".output FILENAME       Send output to FILENAME\n"
   ".output stdout         Send output to the screen\n"
   ".prompt MAIN CONTINUE  Replace the standard prompts\n"
   ".quit                  Exit this program\n"
   ".read FILENAME         Execute SQL in FILENAME\n"
@@ -1445,11 +1447,11 @@
 
 /*
 ** Make sure the database is open.  If it is not, then open it.  If
 ** the database fails to open, print an error message and exit.
 */
-static void open_db(struct callback_data *p){
+static void open_db(struct callback_data *p, int keepAlive){
   if( p->db==0 ){
     sqlite3_open(p->zDbFilename, &p->db);
     db = p->db;
     if( db && sqlite3_errcode(db)==SQLITE_OK ){
       sqlite3_create_function(db, "shellstatic", 0, SQLITE_UTF8, 0,
@@ -1456,10 +1458,11 @@
           shellstaticFunc, 0, 0);
     }
     if( db==0 || SQLITE_OK!=sqlite3_errcode(db) ){
       fprintf(stderr,"Error: unable to open database \"%s\": %s\n", 
           p->zDbFilename, sqlite3_errmsg(db));
+      if( keepAlive ) return;
       exit(1);
     }
 #ifndef SQLITE_OMIT_LOAD_EXTENSION
     sqlite3_enable_load_extension(p->db, 1);
 #endif
@@ -1576,11 +1579,11 @@
     if( rc!=SQLITE_OK ){
       fprintf(stderr, "Error: cannot open \"%s\"\n", zDestFile);
       sqlite3_close(pDest);
       return 1;
     }
-    open_db(p);
+    open_db(p, 0);
     pBackup = sqlite3_backup_init(pDest, "main", p->db, zDb);
     if( pBackup==0 ){
       fprintf(stderr, "Error: %s\n", sqlite3_errmsg(pDest));
       sqlite3_close(pDest);
       return 1;
@@ -1601,11 +1604,11 @@
   }else
 
   if( c=='d' && n>1 && strncmp(azArg[0], "databases", n)==0 && nArg==1 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 1;
     data.mode = MODE_Column;
     data.colWidth[0] = 3;
     data.colWidth[1] = 15;
@@ -1618,11 +1621,11 @@
       rc = 1;
     }
   }else
 
   if( c=='d' && strncmp(azArg[0], "dump", n)==0 && nArg<3 ){
-    open_db(p);
+    open_db(p, 0);
     /* When playing back a "dump", the content might appear in an order
     ** which causes immediate foreign key constraints to be violated.
     ** So disable foreign-key constraint enforcement to prevent problems. */
     fprintf(p->out, "PRAGMA foreign_keys=OFF;\n");
     fprintf(p->out, "BEGIN TRANSACTION;\n");
@@ -1736,11 +1739,11 @@
     char **azCol;               /* zLine[] broken up into columns */
     char *zCommit;              /* How to commit changes */   
     FILE *in;                   /* The input file */
     int lineno = 0;             /* Line number of input file */
 
-    open_db(p);
+    open_db(p, 0);
     nSep = strlen30(p->separator);
     if( nSep==0 ){
       fprintf(stderr, "Error: non-null separator required for import\n");
       return 1;
     }
@@ -1851,11 +1854,11 @@
   }else
 
   if( c=='i' && strncmp(azArg[0], "indices", n)==0 && nArg<3 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 0;
     data.mode = MODE_List;
     if( nArg==1 ){
       rc = sqlite3_exec(p->db,
@@ -1917,11 +1920,11 @@
   if( c=='l' && strncmp(azArg[0], "load", n)==0 && nArg>=2 ){
     const char *zFile, *zProc;
     char *zErrMsg = 0;
     zFile = azArg[1];
     zProc = nArg>=3 ? azArg[2] : 0;
-    open_db(p);
+    open_db(p, 0);
     rc = sqlite3_load_extension(p->db, zFile, zProc, &zErrMsg);
     if( rc!=SQLITE_OK ){
       fprintf(stderr, "Error: %s\n", zErrMsg);
       sqlite3_free(zErrMsg);
       rc = 1;
@@ -1995,10 +1998,30 @@
 
   if( c=='n' && strncmp(azArg[0], "nullvalue", n)==0 && nArg==2 ) {
     sqlite3_snprintf(sizeof(p->nullvalue), p->nullvalue,
                      "%.*s", (int)ArraySize(p->nullvalue)-1, azArg[1]);
   }else
+
+  if( c=='o' && strncmp(azArg[0], "open", n)==0 && n>=2 ){
+    sqlite3 *savedDb = p->db;
+    const char *zSavedFilename = p->zDbFilename;
+    char *zNewFilename = 0;
+    p->db = 0;
+    if( nArg>=2 ){
+      p->zDbFilename = zNewFilename = sqlite3_mprintf("%s", azArg[1]);
+    }
+    open_db(p, 1);
+    if( p->db!=0 ){
+      sqlite3_close(savedDb);
+      sqlite3_free(p->zFreeOnClose);
+      p->zFreeOnClose = zNewFilename;
+    }else{
+      sqlite3_free(zNewFilename);
+      p->db = savedDb;
+      p->zDbFilename = zSavedFilename;
+    }
+  }else
 
   if( c=='o' && strncmp(azArg[0], "output", n)==0 && nArg==2 ){
     if( p->out!=stdout ){
       fclose(p->out);
     }
@@ -2059,11 +2082,11 @@
     if( rc!=SQLITE_OK ){
       fprintf(stderr, "Error: cannot open \"%s\"\n", zSrcFile);
       sqlite3_close(pSrc);
       return 1;
     }
-    open_db(p);
+    open_db(p, 0);
     pBackup = sqlite3_backup_init(p->db, zDb, pSrc, "main");
     if( pBackup==0 ){
       fprintf(stderr, "Error: %s\n", sqlite3_errmsg(p->db));
       sqlite3_close(pSrc);
       return 1;
@@ -2089,11 +2112,11 @@
   }else
 
   if( c=='s' && strncmp(azArg[0], "schema", n)==0 && nArg<3 ){
     struct callback_data data;
     char *zErrMsg = 0;
-    open_db(p);
+    open_db(p, 0);
     memcpy(&data, p, sizeof(data));
     data.showHeader = 0;
     data.mode = MODE_Semi;
     if( nArg>1 ){
       int i;
@@ -2195,11 +2218,11 @@
 
   if( c=='t' && n>1 && strncmp(azArg[0], "tables", n)==0 && nArg<3 ){
     char **azResult;
     int nRow;
     char *zErrMsg;
-    open_db(p);
+    open_db(p, 0);
     if( nArg==1 ){
       rc = sqlite3_get_table(p->db,
         "SELECT name FROM sqlite_master "
         "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%' "
         "UNION ALL "
@@ -2271,11 +2294,11 @@
       { "scratchmalloc",         SQLITE_TESTCTRL_SCRATCHMALLOC          },
     };
     int testctrl = -1;
     int rc = 0;
     int i, n;
-    open_db(p);
+    open_db(p, 0);
 
     /* convert testctrl text option to value. allow any unique prefix
     ** of the option name, or a numerical value. */
     n = strlen30(azArg[1]);
     for(i=0; i<(int)(sizeof(aCtrl)/sizeof(aCtrl[0])); i++){
@@ -2370,20 +2393,20 @@
       }
     }
   }else
 
   if( c=='t' && n>4 && strncmp(azArg[0], "timeout", n)==0 && nArg==2 ){
-    open_db(p);
+    open_db(p, 0);
     sqlite3_busy_timeout(p->db, atoi(azArg[1]));
   }else
     
   if( HAS_TIMER && c=='t' && n>=5 && strncmp(azArg[0], "timer", n)==0
    && nArg==2
   ){
     enableTimer = booleanValue(azArg[1]);
   }else
-  
+
   if( c=='v' && strncmp(azArg[0], "version", n)==0 ){
     printf("SQLite %s %s\n" /*extra-version-info*/,
         sqlite3_libversion(), sqlite3_sourceid());
   }else
 
@@ -2553,11 +2576,11 @@
       nSql += len;
     }
     if( zSql && _contains_semicolon(&zSql[nSqlPrior], nSql-nSqlPrior)
                 && sqlite3_complete(zSql) ){
       p->cnt = 0;
-      open_db(p);
+      open_db(p, 0);
       BEGIN_TIMER;
       rc = shell_exec(p->db, zSql, shell_callback, p, &zErrMsg);
       END_TIMER;
       if( rc || zErrMsg ){
         char zPrefix[100];
@@ -2881,11 +2904,11 @@
   ** file does not exist, delay opening it.  This prevents empty database
   ** files from being created if a user mistypes the database name argument
   ** to the sqlite command-line tool.
   */
   if( access(data.zDbFilename, 0)==0 ){
-    open_db(&data);
+    open_db(&data, 0);
   }
 
   /* Process the initialization file if there is one.  If no -init option
   ** is given on the command line, look for a file named ~/.sqliterc and
   ** try to process it.
@@ -2973,11 +2996,11 @@
       z = argv[i];
       if( z[0]=='.' ){
         rc = do_meta_command(z, &data);
         if( rc && bail_on_error ) return rc;
       }else{
-        open_db(&data);
+        open_db(&data, 0);
         rc = shell_exec(data.db, z, shell_callback, &data, &zErrMsg);
         if( zErrMsg!=0 ){
           fprintf(stderr,"Error: %s\n", zErrMsg);
           if( bail_on_error ) return rc!=0 ? rc : 1;
         }else if( rc!=0 ){
@@ -2996,11 +3019,11 @@
     /* Run just the command that follows the database name
     */
     if( zFirstCmd[0]=='.' ){
       rc = do_meta_command(zFirstCmd, &data);
     }else{
-      open_db(&data);
+      open_db(&data, 0);
       rc = shell_exec(data.db, zFirstCmd, shell_callback, &data, &zErrMsg);
       if( zErrMsg!=0 ){
         fprintf(stderr,"Error: %s\n", zErrMsg);
         return rc!=0 ? rc : 1;
       }else if( rc!=0 ){
@@ -3044,7 +3067,8 @@
   }
   set_table_name(&data, 0);
   if( data.db ){
     sqlite3_close(data.db);
   }
+  sqlite3_free(data.zFreeOnClose); 
   return rc;
 }