path: root/src/mongo/shell/dbshell.cpp

// dbshell.cpp
/*
 *    Copyright 2010 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects
 *    for all of the code used other than as permitted herein. If you modify
 *    file(s) with this exception, you may extend this exception to your
 *    version of the file(s), but you are not obligated to do so. If you do not
 *    wish to do so, delete this exception statement from your version. If you
 *    delete this exception statement from all source files in the program,
 *    then also delete it in the license file.
 */

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault

#include "mongo/platform/basic.h"

#include <boost/filesystem/operations.hpp>
#include <fstream>
#include <iostream>
#include <pcrecpp.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

#include "mongo/base/initializer.h"
#include "mongo/base/status.h"
#include "mongo/client/dbclientinterface.h"
#include "mongo/client/sasl_client_authenticate.h"
#include "mongo/db/client.h"
#include "mongo/db/log_process_details.h"
#include "mongo/db/server_options.h"
#include "mongo/logger/console_appender.h"
#include "mongo/logger/logger.h"
#include "mongo/logger/message_event_utf8_encoder.h"
#include "mongo/scripting/engine.h"
#include "mongo/shell/linenoise.h"
#include "mongo/shell/shell_options.h"
#include "mongo/shell/shell_utils.h"
#include "mongo/shell/shell_utils_launcher.h"
#include "mongo/util/exit_code.h"
#include "mongo/util/file.h"
#include "mongo/util/log.h"
#include "mongo/util/net/ssl_options.h"
#include "mongo/util/password.h"
#include "mongo/util/quick_exit.h"
#include "mongo/util/signal_handlers.h"
#include "mongo/util/stacktrace.h"
#include "mongo/util/startup_test.h"
#include "mongo/util/static_observer.h"
#include "mongo/util/text.h"
#include "mongo/util/version.h"

#ifdef _WIN32
#include <io.h>
#include <shlobj.h>
#define isatty _isatty
#define fileno _fileno
#else
#include <unistd.h>
#endif

using namespace std;
using namespace mongo;

string historyFile;
bool gotInterrupted = false;
bool inMultiLine = false;
static volatile bool atPrompt = false; // can eval before getting to prompt

namespace mongo {

    Scope * shellMainScope;

    extern bool dbexitCalled;
}

void generateCompletions( const string& prefix , vector<string>& all ) {
    if ( prefix.find( '"' ) != string::npos )
        return;

    try {
        BSONObj args = BSON( "0" << prefix );
        shellMainScope->invokeSafe("function callShellAutocomplete(x) {shellAutocomplete(x)}",
                                   &args,
                                   NULL);
        BSONObjBuilder b;
        shellMainScope->append( b , "" , "__autocomplete__" );
        BSONObj res = b.obj();
        BSONObj arr = res.firstElement().Obj();

        BSONObjIterator i( arr );
        while ( i.more() ) {
            BSONElement e = i.next();
            all.push_back( e.String() );
        }
    }
    catch ( ... ) {
    }
}

void completionHook( const char* text , linenoiseCompletions* lc ) {
    vector<string> all;
    generateCompletions( text , all );

    for ( unsigned i = 0; i < all.size(); ++i )
        linenoiseAddCompletion( lc , (char*)all[i].c_str() );
}

void shellHistoryInit() {
    stringstream ss;
    const char * h = shell_utils::getUserDir();
    if ( h )
        ss << h << "/";
    ss << ".dbshell";
    historyFile = ss.str();

    linenoiseHistoryLoad( historyFile.c_str() );
    linenoiseSetCompletionCallback( completionHook );
}

void shellHistoryDone() {
    linenoiseHistorySave( historyFile.c_str() );
    linenoiseHistoryFree();
}
void shellHistoryAdd( const char * line ) {
    if ( line[0] == '\0' )
        return;

    // dont record duplicate lines
    static string lastLine;
    if ( lastLine == line )
        return;
    lastLine = line;

    // We don't want any .auth() or .createUser() shell helpers added, but we want to
    // be able to add things like `.author`, so be smart about how this is
    // detected by using regular expresions. This is so we can avoid storing passwords
    // in the history file in plaintext.
    static pcrecpp::RE hiddenHelpers(
            "\\.\\s*(auth|createUser|updateUser|changeUserPassword)\\s*\\(");
    // Also don't want the raw user management commands to show in the shell when run directly
    // via runCommand.
    static pcrecpp::RE hiddenCommands(
                "(run|admin)Command\\s*\\(\\s*{\\s*(createUser|updateUser)\\s*:");
    if (!hiddenHelpers.PartialMatch(line) && !hiddenCommands.PartialMatch(line))
    {
        linenoiseHistoryAdd( line );
    }
}

void killOps() {
    if ( mongo::shell_utils::_nokillop )
        return;

    if ( atPrompt )
        return;

    sleepmillis(10); // give current op a chance to finish

    mongo::shell_utils::connectionRegistry.
        killOperationsOnAllConnections(!shellGlobalParams.autoKillOp);
}

// Stubs for signal_handlers.cpp
namespace mongo {
    void logProcessDetailsForLogRotate() {}

    void exitCleanly(ExitCode code) {
        {
            stdx::lock_guard<stdx::mutex> lk(mongo::shell_utils::mongoProgramOutputMutex);
            mongo::dbexitCalled = true;
        }

        ::killOps();
        ::shellHistoryDone();
        quickExit(0);
    }
}

void quitNicely( int sig ) {
    exitCleanly(EXIT_CLEAN);
}

// the returned string is allocated with strdup() or malloc() and must be freed by calling free()
char * shellReadline( const char * prompt , int handlesigint = 0 ) {
    atPrompt = true;

    char * ret = linenoise( prompt );
    if ( ! ret ) {
        gotInterrupted = true;  // got ^C, break out of multiline
    }

    atPrompt = false;
    return ret;
}

void setupSignals() {
    signal( SIGINT , quitNicely );
}

string fixHost( const std::string& url, const std::string& host, const std::string& port ) {
    if ( host.size() == 0 && port.size() == 0 ) {
        if ( url.find( "/" ) == string::npos ) {
            // check for ips
            if ( url.find( "." ) != string::npos )
                return url + "/test";

            if ( url.rfind( ":" ) != string::npos &&
                    isdigit( url[url.rfind(":")+1] ) )
                return url + "/test";
        }
        return url;
    }

    if ( url.find( "/" ) != string::npos ) {
        cerr << "url can't have host or port if you specify them individually" << endl;
        quickExit(-1);
    }

    string newurl( ( host.size() == 0 ) ? "127.0.0.1" : host );
    if ( port.size() > 0 )
        newurl += ":" + port;
    else if ( host.find(':') == string::npos ) {
        // need to add port with IPv6 addresses
        newurl += ":27017";
    }

    newurl += "/" + url;

    return newurl;
}

static string OpSymbols = "~!%^&*-+=|:,<>/?.";

bool isOpSymbol( char c ) {
    for ( size_t i = 0; i < OpSymbols.size(); i++ )
        if ( OpSymbols[i] == c ) return true;
    return false;
}

bool isUseCmd( const std::string& code ) {
    string cmd = code;
    if ( cmd.find( " " ) > 0 )
        cmd = cmd.substr( 0 , cmd.find( " " ) );
    return cmd == "use";
}

/**
 * Skip over a quoted string, including quotes escaped with backslash
 * 
 * @param code      String
 * @param start     Starting position within string, always > 0
 * @param quote     Quote character (single or double quote)
 * @return          Position of ending quote, or code.size() if no quote found
 */
size_t skipOverString(const std::string& code, size_t start, char quote) {
    size_t pos = start;
    while (pos < code.size()) {
        pos = code.find(quote, pos);
        if (pos == std::string::npos) {
            return code.size();
        }
        // We want to break if the quote we found is not escaped, but we need to make sure
        // that the escaping backslash is not itself escaped.  Comparisons of start and pos
        // are to keep us from reading beyond the beginning of the quoted string.
        //
        if (start == pos     || code[pos - 1] != '\\' || // previous char was backslash
            start == pos - 1 || code[pos - 2] == '\\'    // char before backslash was not another
        ) {
            break;  // The quote we found was not preceded by an unescaped backslash; it is real
        }
        ++pos;      // The quote we found was escaped with backslash, so it doesn't count
    }
    return pos;
}

bool isBalanced( const std::string& code ) {
    if (isUseCmd( code ))
        return true;  // don't balance "use <dbname>" in case dbname contains special chars
    int curlyBrackets = 0;
    int squareBrackets = 0;
    int parens = 0;
    bool danglingOp = false;

    for ( size_t i=0; i<code.size(); i++ ) {
        switch( code[i] ) {
        case '/':
            if ( i + 1 < code.size() && code[i+1] == '/' ) {
                while ( i  <code.size() && code[i] != '\n' )
                    i++;
            }
            continue;
        case '{':
            curlyBrackets++;
            break;
        case '}':
            if ( curlyBrackets <= 0 )
                return true;
            curlyBrackets--;
            break;
        case '[':
            squareBrackets++;
            break;
        case ']':
            if ( squareBrackets <= 0 )
                return true;
            squareBrackets--;
            break;
        case '(':
            parens++;
            break;
        case ')':
            if ( parens <= 0 )
                return true;
            parens--;
            break;
        case '"':
        case '\'':
            i = skipOverString(code, i + 1, code[i]);
            if (i >= code.size()) {
                return true;            // Do not let unterminated strings enter multi-line mode
            }
            break;
        case '\\':
            if ( i + 1 < code.size() && code[i+1] == '/' ) i++;
            break;
        case '+':
        case '-':
            if ( i + 1 < code.size() && code[i+1] == code[i] ) {
                i++;
                continue; // postfix op (++/--) can't be a dangling op
            }
            break;
        }
        if ( i >= code.size() ) {
            danglingOp = false;
            break;
        }
        if ( isOpSymbol( code[i] ) ) danglingOp = true;
        else if ( !std::isspace( static_cast<unsigned char>( code[i] ) ) ) danglingOp = false;
    }

    return curlyBrackets == 0 && squareBrackets == 0 && parens == 0 && !danglingOp;
}

struct BalancedTest : public mongo::StartupTest {
public:
    void run() {
        verify( isBalanced( "x = 5" ) );
        verify( isBalanced( "function(){}" ) );
        verify( isBalanced( "function(){\n}" ) );
        verify( ! isBalanced( "function(){" ) );
        verify( isBalanced( "x = \"{\";" ) );
        verify( isBalanced( "// {" ) );
        verify( ! isBalanced( "// \n {" ) );
        verify( ! isBalanced( "\"//\" {" ) );
        verify( isBalanced( "{x:/x\\//}" ) );
        verify( ! isBalanced( "{ \\/// }" ) );
        verify( isBalanced( "x = 5 + y " ) );
        verify( ! isBalanced( "x = " ) );
        verify( ! isBalanced( "x = // hello" ) );
        verify( ! isBalanced( "x = 5 +" ) );
        verify( isBalanced( " x ++" ) );
        verify( isBalanced( "-- x" ) );
        verify( !isBalanced( "a." ) );
        verify( !isBalanced( "a. " ) );
        verify( isBalanced( "a.b" ) );

        // SERVER-5809 and related cases -- 
        verify( isBalanced( "a = {s:\"\\\"\"}" ) );             // a = {s:"\""}
        verify( isBalanced( "db.test.save({s:\"\\\"\"})" ) );   // db.test.save({s:"\""})
        verify( isBalanced( "printjson(\" \\\" \")" ) );        // printjson(" \" ") -- SERVER-8554
        verify( isBalanced( "var a = \"\\\\\";" ) );            // var a = "\\";
        verify( isBalanced( "var a = (\"\\\\\") //\"" ) );      // var a = ("\\") //"
        verify( isBalanced( "var a = (\"\\\\\") //\\\"" ) );    // var a = ("\\") //\"
        verify( isBalanced( "var a = (\"\\\\\") //" ) );        // var a = ("\\") //
        verify( isBalanced( "var a = (\"\\\\\")" ) );           // var a = ("\\")
        verify( isBalanced( "var a = (\"\\\\\\\"\")" ) );       // var a = ("\\\"")
        verify( ! isBalanced( "var a = (\"\\\\\" //\"" ) );     // var a = ("\\" //"
        verify( ! isBalanced( "var a = (\"\\\\\" //" ) );       // var a = ("\\" //
        verify( ! isBalanced( "var a = (\"\\\\\"" ) );          // var a = ("\\"
    }
} balanced_test;

string finishCode( string code ) {
    while ( ! isBalanced( code ) ) {
        inMultiLine = true;
        code += "\n";
        // cancel multiline if two blank lines are entered
        if ( code.find( "\n\n\n" ) != string::npos )
            return ";";
        char * line = shellReadline( "... " , 1 );
        if ( gotInterrupted ) {
            if ( line )
                free( line );
            return "";
        }
        if ( ! line )
            return "";

        char * linePtr = line;
        while ( str::startsWith( linePtr, "... " ) )
            linePtr += 4;

        code += linePtr;
        free( line );
    }
    return code;
}

bool execPrompt( mongo::Scope &scope, const char *promptFunction, string &prompt ) {
    string execStatement = string( "__prompt__ = " ) + promptFunction + "();";
    scope.exec( "delete __prompt__;", "", false, false, false, 0 );
    scope.exec( execStatement, "", false, false, false, 0 );
    if ( scope.type( "__prompt__" ) == String ) {
        prompt = scope.getString( "__prompt__" );
        return true;
    }
    return false;
}

/**
 * Edit a variable or input buffer text in an external editor -- EDITOR must be defined
 *
 * @param whatToEdit Name of JavaScript variable to be edited, or any text string
 */
static void edit( const string& whatToEdit ) {

    // EDITOR may be defined in the JavaScript scope or in the environment
    string editor;
    if ( shellMainScope->type( "EDITOR" ) == String ) {
        editor = shellMainScope->getString( "EDITOR" );
    }
    else {
        static const char * editorFromEnv = getenv( "EDITOR" );
        if ( editorFromEnv ) {
            editor = editorFromEnv;
        }
    }
    if ( editor.empty() ) {
        cout << "please define EDITOR as a JavaScript string or as an environment variable" << endl;
        return;
    }

    // "whatToEdit" might look like a variable/property name
    bool editingVariable = true;
    for ( const char* p = whatToEdit.c_str(); *p; ++p ) {
        if ( ! ( isalnum( *p ) || *p == '_' || *p == '.' ) ) {
            editingVariable = false;
            break;
        }
    }

    string js;
    if ( editingVariable ) {
        // If "whatToEdit" is undeclared or uninitialized, declare 
        int varType = shellMainScope->type( whatToEdit.c_str() );
        if ( varType == Undefined ) {
            shellMainScope->exec( "var " + whatToEdit , "(shell)", false, true, false );
        }

        // Convert "whatToEdit" to JavaScript (JSON) text
        if ( !shellMainScope->exec( "__jsout__ = tojson(" + whatToEdit + ")", "tojs", false, false, false ) )
            return; // Error already printed

        js = shellMainScope->getString( "__jsout__" );

        if ( strstr( js.c_str(), "[native code]" ) ) {
            cout << "can't edit native functions" << endl;
            return;
        }
    }
    else {
        js = whatToEdit;
    }

    // Pick a name to use for the temp file
    string filename;
    const int maxAttempts = 10;
    int i;
    for ( i = 0; i < maxAttempts; ++i ) {
        StringBuilder sb;
#ifdef _WIN32
        char tempFolder[MAX_PATH];
        GetTempPathA( sizeof tempFolder, tempFolder );
        sb << tempFolder << "mongo_edit" << time( 0 ) + i << ".js";
#else
        sb << "/tmp/mongo_edit" << time( 0 ) + i << ".js";
#endif
        filename = sb.str();
        if (!::mongo::shell_utils::fileExists(filename))
            break;
    }
    if ( i == maxAttempts ) {
        cout << "couldn't create unique temp file after " << maxAttempts << " attempts" << endl;
        return;
    }

    // Create the temp file
    FILE * tempFileStream;
    tempFileStream = fopen( filename.c_str(), "wt" );
    if ( ! tempFileStream ) {
        cout << "couldn't create temp file (" << filename << "): " << errnoWithDescription() << endl;
        return;
    }

    // Write JSON into the temp file
    size_t fileSize = js.size();
    if ( fwrite( js.data(), sizeof( char ), fileSize, tempFileStream ) != fileSize ) {
        int systemErrno = errno;
        cout << "failed to write to temp file: " << errnoWithDescription( systemErrno ) << endl;
        fclose( tempFileStream );
        remove( filename.c_str() );
        return;
    }
    fclose( tempFileStream );

    // Pass file to editor
    StringBuilder sb;
    sb << editor << " " << filename;
    int ret = ::system( sb.str().c_str() );
    if ( ret ) {
        if ( ret == -1 ) {
            int systemErrno = errno;
            cout << "failed to launch $EDITOR (" << editor << "): " << errnoWithDescription( systemErrno ) << endl;
        }
        else
            cout << "editor exited with error (" << ret << "), not applying changes" << endl;
        remove( filename.c_str() );
        return;
    }

    // The editor gave return code zero, so read the file back in
    tempFileStream = fopen( filename.c_str(), "rt" );
    if ( ! tempFileStream ) {
        cout << "couldn't open temp file on return from editor: " << errnoWithDescription() << endl;
        remove( filename.c_str() );
        return;
    }
    sb.reset();
    int bytes;
    do {
        char buf[1024];
        bytes = fread( buf, sizeof( char ), sizeof buf, tempFileStream );
        if ( ferror( tempFileStream ) ) {
            cout << "failed to read temp file: " << errnoWithDescription() << endl;
            fclose( tempFileStream );
            remove( filename.c_str() );
            return;
        }
        sb.append( StringData( buf, bytes ) );
    } while ( bytes );

    // Done with temp file, close and delete it
    fclose( tempFileStream );
    remove( filename.c_str() );

    if ( editingVariable ) {
        // Try to execute assignment to copy edited value back into the variable
        const string code = whatToEdit + string( " = " ) + sb.str();
        if ( !shellMainScope->exec( code, "tojs", false, true, false ) ) {
            cout << "error executing assignment: " << code << endl;
        }
    }
    else {
        linenoisePreloadBuffer( sb.str().c_str() );
    }
}

int _main( int argc, char* argv[], char **envp ) {
    setupSignalHandlers(true);
    setupSignals();

    mongo::shell_utils::RecordMyLocation( argv[ 0 ] );

    shellGlobalParams.url = "test";

    mongo::runGlobalInitializersOrDie(argc, argv, envp);

    // hide password from ps output
    for ( int i = 0; i < (argc-1); ++i ) {
        if ( !strcmp(argv[i], "-p") || !strcmp( argv[i], "--password" ) ) {
            char* arg = argv[i + 1];
            while ( *arg ) {
                *arg++ = 'x';
            }
        }
    }

    if (!mongo::serverGlobalParams.quiet)
        cout << "MongoDB shell version: " << mongo::versionString << endl;

    mongo::StartupTest::runTests();

    logger::globalLogManager()->getNamedDomain("javascriptOutput")->attachAppender(
            logger::MessageLogDomain::AppenderAutoPtr(
                    new logger::ConsoleAppender<logger::MessageEventEphemeral>(
                            new logger::MessageEventUnadornedEncoder)));

    if (!shellGlobalParams.nodb) { // connect to db
        stringstream ss;
        if (mongo::serverGlobalParams.quiet)
            ss << "__quiet = true;";
        ss << "db = connect( \""
           << fixHost(shellGlobalParams.url, shellGlobalParams.dbhost, shellGlobalParams.port)
           << "\")";

        mongo::shell_utils::_dbConnect = ss.str();

        if (shellGlobalParams.usingPassword && shellGlobalParams.password.empty()) {
            shellGlobalParams.password = mongo::askPassword();
        }
    }

    // Construct the authentication-related code to execute on shell startup.
    //
    // This constructs and immediately executes an anonymous function, to avoid
    // the shell's default behavior of printing statement results to the console.
    //
    // It constructs a statement of the following form:
    //
    // (function() {
    //    // Set default authentication mechanism and, maybe, authenticate.
    //  }())
    stringstream authStringStream;
    authStringStream << "(function() { " << endl;
    if (!shellGlobalParams.authenticationMechanism.empty()) {
        authStringStream << "DB.prototype._defaultAuthenticationMechanism = \"" <<
            escape(shellGlobalParams.authenticationMechanism) << "\";" << endl;
    }

    if (!shellGlobalParams.gssapiServiceName.empty()) {
        authStringStream << "DB.prototype._defaultGssapiServiceName = \"" <<
            escape(shellGlobalParams.gssapiServiceName) << "\";" << endl;
    }

    if (!shellGlobalParams.nodb && shellGlobalParams.username.size()) {
        authStringStream << "var username = \"" << escape(shellGlobalParams.username) << "\";" <<
            endl;
        if (shellGlobalParams.usingPassword) {
            authStringStream << "var password = \"" << escape(shellGlobalParams.password) << "\";"
                             << endl;
        }
        if (shellGlobalParams.authenticationDatabase.empty()) {
            authStringStream << "var authDb = db;" << endl;
        }
        else {
            authStringStream << "var authDb = db.getSiblingDB(\""
                             << escape(shellGlobalParams.authenticationDatabase) << "\");" << endl;
        }
        authStringStream << "authDb._authOrThrow({ " <<
            saslCommandUserFieldName << ": username ";
        if (shellGlobalParams.usingPassword) { 
            authStringStream << ", " << saslCommandPasswordFieldName << ": password ";
        }

        if (!shellGlobalParams.gssapiHostName.empty()) {
            authStringStream << ", " << saslCommandServiceHostnameFieldName << ": \""
                             << escape(shellGlobalParams.gssapiHostName) << '"' << endl;
        }
        authStringStream << "});" << endl;
    }
    authStringStream << "}())";
    mongo::shell_utils::_dbAuth = authStringStream.str();

    mongo::ScriptEngine::setConnectCallback( mongo::shell_utils::onConnect );
    mongo::ScriptEngine::setup();
    mongo::globalScriptEngine->setScopeInitCallback( mongo::shell_utils::initScope );
    unique_ptr< mongo::Scope > scope( mongo::globalScriptEngine->newScope() );
    shellMainScope = scope.get();

    if( shellGlobalParams.runShell )
        cout << "type \"help\" for help" << endl;
   
    // Load and execute /etc/mongorc.js before starting shell
    std::string rcGlobalLocation;
#ifndef _WIN32
    rcGlobalLocation = "/etc/mongorc.js" ;
#else
    wchar_t programDataPath[MAX_PATH];
    if ( S_OK == SHGetFolderPathW(NULL,
                                CSIDL_COMMON_APPDATA,
                                NULL,
                                0,
                                programDataPath) ) {
        rcGlobalLocation = str::stream() << toUtf8String(programDataPath)
                                         << "\\MongoDB\\mongorc.js";
    }
#endif   
    if ( !rcGlobalLocation.empty() && ::mongo::shell_utils::fileExists(rcGlobalLocation) ) {
        if ( ! scope->execFile( rcGlobalLocation , false , true ) ) {
            cout << "The \"" << rcGlobalLocation << "\" file could not be executed" << endl;
        }
    }

    if ( !shellGlobalParams.script.empty() ) {
        mongo::shell_utils::MongoProgramScope s;
        if ( ! scope->exec( shellGlobalParams.script , "(shell eval)" , true , true , false ) )
            return -4;
    }

    for (size_t i = 0; i < shellGlobalParams.files.size(); ++i) {
        mongo::shell_utils::MongoProgramScope s;

        if ( shellGlobalParams.files.size() > 1 )
            cout << "loading file: " << shellGlobalParams.files[i] << endl;

        if ( ! scope->execFile( shellGlobalParams.files[i] , false , true ) ) {
            cout << "failed to load: " << shellGlobalParams.files[i] << endl;
            return -3;
        }
    }

    if ( shellGlobalParams.files.size() == 0 && shellGlobalParams.script.empty() )
        shellGlobalParams.runShell = true;

    if ( shellGlobalParams.runShell ) {

        mongo::shell_utils::MongoProgramScope s;
        // If they specify norc, assume it's not their first time
        bool hasMongoRC = shellGlobalParams.norc;
        string rcLocation;
        if ( !shellGlobalParams.norc ) {
#ifndef _WIN32
            if ( getenv( "HOME" ) != NULL )
                rcLocation = str::stream() << getenv( "HOME" ) << "/.mongorc.js" ;
#else
            if ( getenv( "HOMEDRIVE" ) != NULL && getenv( "HOMEPATH" ) != NULL )
                rcLocation = str::stream() << toUtf8String(_wgetenv(L"HOMEDRIVE"))
                                           << toUtf8String(_wgetenv(L"HOMEPATH"))
                                           << "\\.mongorc.js";
#endif
            if ( !rcLocation.empty() && ::mongo::shell_utils::fileExists(rcLocation) ) {
                hasMongoRC = true;
                if ( ! scope->execFile( rcLocation , false , true ) ) {
                    cout << "The \".mongorc.js\" file located in your home folder could not be executed" << endl;
                    return -5;
                }
            }
        }

        if ( !hasMongoRC && isatty(fileno(stdin)) ) {
            cout << "Welcome to the MongoDB shell.\n"
                    "For interactive help, type \"help\".\n"
                    "For more comprehensive documentation, see\n\thttp://docs.mongodb.org/\n"
                    "Questions? Try the support group\n\thttp://groups.google.com/group/mongodb-user" << endl;
            File f;
            f.open(rcLocation.c_str(), false);  // Create empty .mongorc.js file
        }

        if (!shellGlobalParams.nodb && !mongo::serverGlobalParams.quiet && isatty(fileno(stdin))) {
            scope->exec( "shellHelper( 'show', 'startupWarnings' )", "(shellwarnings", false, true, false );
        }

        shellHistoryInit();

        string prompt;
        int promptType;

        while ( 1 ) {
            inMultiLine = false;
            gotInterrupted = false;

            promptType = scope->type( "prompt" );
            if ( promptType == String ) {
                prompt = scope->getString( "prompt" );
            }
            else if ( ( promptType == Code ) &&
                     execPrompt( *scope, "prompt", prompt ) ) {
            }
            else if ( execPrompt( *scope, "defaultPrompt", prompt ) ) {
            }
            else {
                prompt = "> ";
            }

            char * line = shellReadline( prompt.c_str() );

            char * linePtr = line;  // can't clobber 'line', we need to free() it later
            if ( linePtr ) {
                while ( linePtr[0] == ' ' )
                    ++linePtr;
                int lineLen = strlen( linePtr );
                while ( lineLen > 0 && linePtr[lineLen - 1] == ' ' )
                    linePtr[--lineLen] = 0;
            }

            if ( ! linePtr || ( strlen( linePtr ) == 4 && strstr( linePtr , "exit" ) ) ) {
                if (!mongo::serverGlobalParams.quiet)
                    cout << "bye" << endl;
                if ( line )
                    free( line );
                break;
            }

            string code = linePtr;
            if ( code == "exit" || code == "exit;" ) {
                free( line );
                break;
            }
            if ( code == "cls" ) {
                free( line );
                linenoiseClearScreen();
                continue;
            }

            if ( code.size() == 0 ) {
                free( line );
                continue;
            }

            if ( str::startsWith( linePtr, "edit " ) ) {
                shellHistoryAdd( linePtr );

                const char* s = linePtr + 5; // skip "edit "
                while( *s && isspace( *s ) )
                    s++;

                edit( s );
                free( line );
                continue;
            }

            gotInterrupted = false;
            code = finishCode( code );
            if ( gotInterrupted ) {
                cout << endl;
                free( line );
                continue;
            }

            if ( code.size() == 0 ) {
                free( line );
                break;
            }

            bool wascmd = false;
            {
                string cmd = linePtr;
                if ( cmd.find( " " ) > 0 )
                    cmd = cmd.substr( 0 , cmd.find( " " ) );

                if ( cmd.find( "\"" ) == string::npos ) {
                    try {
                        scope->exec( (string)"__iscmd__ = shellHelper[\"" + cmd + "\"];" , "(shellhelp1)" , false , true , true );
                        if ( scope->getBoolean( "__iscmd__" )  ) {
                            scope->exec( (string)"shellHelper( \"" + cmd + "\" , \"" + code.substr( cmd.size() ) + "\");" , "(shellhelp2)" , false , true , false );
                            wascmd = true;
                        }
                    }
                    catch ( std::exception& e ) {
                        cout << "error2:" << e.what() << endl;
                        wascmd = true;
                    }
                }
            }

            if ( ! wascmd ) {
                try {
                    if ( scope->exec( code.c_str() , "(shell)" , false , true , false ) )
                        scope->exec( "shellPrintHelper( __lastres__ );" , "(shell2)" , true , true , false );
                }
                catch ( std::exception& e ) {
                    cout << "error:" << e.what() << endl;
                }
            }

            shellHistoryAdd( code.c_str() );
            free( line );
        }

        shellHistoryDone();
    }

    {
        stdx::lock_guard<stdx::mutex> lk(mongo::shell_utils::mongoProgramOutputMutex);
        mongo::dbexitCalled = true;
    }
    return 0;
}

#ifdef _WIN32
int wmain(int argc, wchar_t* argvW[], wchar_t* envpW[]) {
    static mongo::StaticObserver staticObserver;
    int returnCode;
    try {
        WindowsCommandLine wcl(argc, argvW, envpW);
        returnCode = _main(argc, wcl.argv(), wcl.envp());
    }
    catch ( mongo::DBException& e ) {
        cerr << "exception: " << e.what() << endl;
        returnCode = 1;
    }
    quickExit(returnCode);
}
#else // #ifdef _WIN32
int main( int argc, char* argv[], char **envp ) {
    static mongo::StaticObserver staticObserver;
    int returnCode;
    try {
        returnCode = _main( argc , argv, envp );
    }
    catch ( mongo::DBException& e ) {
        cerr << "exception: " << e.what() << endl;
        returnCode = 1;
    }
    quickExit(returnCode);
}
#endif // #ifdef _WIN32