QUEL Reference Guide > QUEL Reference Guide > QUEL and EQUEL Statements > CALL--Call an Ingres Tool or the Operating System
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CALL--Call an Ingres Tool or the Operating System
Valid in: EQUEL
Calls an Ingres tool (such as RBF or Report-Writer) or the operating system.
This statement has the following format:
To call an Ingres tool:
## call subsystem (database = dbname {, parameter = value})
To call the operating system:
## call system (command = command_string)
The call statement enables you to call an Ingres tool from within an embedded QUEL program. When calling an Ingres tool:
Must be the name of an Ingres tool
Must be the name of the current database. You cannot invoke the Ingres tool on a different database.
Must be the name of a parameter accepted by the Ingres tool being called
Must be the value to be assigned to the parameter. If a particular parameter has no value, a null string (empty quotes) must be used.
Note:  When your application calls an Ingres tool, the state of open transactions, open cursors, and repeat queries is not preserved. Each call to an Ingres tool must be considered as a separate DBMS server session.
When the user exits from the Ingres tool, control passes to the statement following the call. When used to call the operating system, the specified command_string is executed as if the user typed it at the operating system command line.
If command_string is a null, empty, or blank string, the statement transfers control to the operating system. The user can execute any operating system commands. Logging out returns the user to the application.
For more information about calling Ingres tools, see Calling Ingres Tools from Embedded QUEL on page 1.
Last modified date: 06/08/2023