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There are switches or "driver strings" you can set to control the way your application creates, reads, and writes files with a specific driver. Driver strings are simply messages or parameters that are sent to the file driver at run-time to control its behavior. The various driver specific driver strings are described in the //Driver Strings //section for each driver.

Driver strings are sent in three ways: with the OPEN or CREATE statement, with the SEND procedure, and with property syntax.

**DRIVER('Driver', '/DriverString = value')**

The OPEN(file) and CREATE(file) statements send any driver strings specified in the FILE's DRIVER attribute. OPEN sends the string immediately //before //the file is opened. You may specify these driver strings with a hand coded FILE declaration (see //[[driver  specify data file type .htm|DRIVER]] //in the //Language Reference// for more information) or in the Data Dictionary (**Driver Options **field in the **File Properties**// //dialog--see //File Properties// ). In either case, you must prepend a forward slash (/) to the driver string. For example:

**MyFile FILE,DRIVER('TopSpeed','/LOGFILE=MyFile.Log')**

** CODE**

** OPEN(MyFile)         !sends the LOGFILE driver string**

**SEND(file, 'DriverString')**

The SEND function sends a driver string to the file driver at any time, including before the file is opened. SEND functions take two forms--//with //an equal sign to change the value of the switch, and //without //an equal sign to return the value of the switch. With SEND, the ISAM drivers do not require the preceeding forward slash, but the SQL drivers do require it. For example:

**SEND(MyFile,'LOGFILE='&MyLogFile)             !Set the logfile**

**MyLogFile=SEND(MySQLFile,'/LOGFILE')          !Query the logfile**

**OldLogFile=SEND(MyFile,'LOGFILE='&NewLogFile) !Set & Query the logfile**

**file{PROP:DriverString}**

Property syntax is an alternative to the SEND function. With property syntax you can send a driver string to the file driver any time //after //the file is opened. With property syntax, the driver string does not require the preceeding forward slash. For example:

**MyLogFile = 'MyFile.Log'**

**MyFile{PROP:Profile}=MyLogFile   !Set the logfile**

**MyLogFile = MyFile{PROP:Profile} !Query the logfile**

**See Also:**

[[ascii driver strings.htm|ASCII Driver Strings]]

[[basic driver strings.htm|Basic:Driver Strings]]

[[btrieve driver strings.htm|Btrieve:Driver Strings]]

[[clarion driver strings.htm|Clarion:Driver Strings]]

[[clipper driver strings.htm|Clipper:Driver Strings]]

[[dbaseiii driver strings.htm|dBaseIII:Driver Strings]]

[[dbaseiv driver strings.htm|dBaseIV:Driver Strings]]

[[dos driver strings.htm|DOS:Driver Strings]]

[[foxpro driver strings.htm|FoxPro:Driver Strings]]

[[topspeed driver strings.htm|TopSpeed: Driver Strings]]

[[sql driver strings.htm|SQL Driver Strings]]

[[mssql accelerator driver strings.htm|MSSQL Accelerator Driver Strings]]

[[h532eu.htm|ODBC:Driver Strings]]

[[oracle accelerator driver strings.htm|Oracle Accelerator Driver Strings]]

[[sqlanywhere accelerator driver strings.htm|SQLAnywhere Accelerator Driver Strings]]