Use the OS-COMMAND statement to execute an operating system statement that you cannot execute using the OS statements listed in Standard system commands. The OS-COMMAND statement provides a generic, operating-system-independent way to escape to the current operating system, which lets you:

  • Execute a OpenEdge or operating system command that has the same syntax on two or more different operating systems.
  • Start an operating system shell.
  • Execute an operating system statement that a user enters.

The arguments to OS-COMMAND must be appropriate for the current operating system. Therefore, where possible, read these arguments at run time from the user, database table, or environment variables rather than hard coding them. The following procedure prompts the user for an operating system command, then uses the OS-COMMAND statement to execute the command:

DEFINE VARIABLE comm-line AS CHARACTER FORMAT "x(70)".
REPEAT:
     UPDATE comm-line.
     OS-COMMAND VALUE(comm-line).
END.

The OS-COMMAND statement eliminates the need to use the OPSYS function to determine the operating system. However, if you cannot use the OS-COMMAND statement, use the OPSYS function to determine the operating system you are running on, and use conditional logic to execute the appropriate code using one of the operating-system-specific escape statements.

The NO-WAIT option of OS-COMMAND is valid only in multi-tasking environments. This option causes OpenEdge to pass control to the statement following the OS-COMMAND, without waiting for the operating system command to terminate. If you are using the OS-COMMAND statement to run an independent Windows application, use the NO-WAIT option.

For more information, see the OS-COMMAND Statement reference entry in ABL Reference.