Return type: Integer
Returns:       The numeric value of the command from the system.

Syntax

system-call string-expression

Allows an operating-system-specific command to be executed in an OmniMark program. This operator must be followed by a string expression that contains a system-specific command. system-call invokes that command and returns the numeric result code returned by that command when it completes its task.

Because the system-call operator returns a numeric value, it must be used in a context where a numeric expression is required. The string expression contains the name of the program to run, as well as any command-line arguments that are being passed to it.

The function being provided by system-call and the value it returns depends on the system on which OmniMark is running. The built-in stream #platform-info can supply some of this information.

In this example, an editing session is called with the name of the file to edit. After the system-call is made, a check for a negative value is made, which presumably means that the editor, "sled", could not be found. Note that because the system-call is made from a condition, it occurs before the output action actually takes place.

  find "\input{" any++ => file-name "}"
    output "couldn't start the SLED editor%n"
          when system-call "sled %g(file-name)" < 0

Related Syntax    #platform-info

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