4.  Error Handling  

      The default error behavior of the primitive procedures defined by the UNIX extension is to invoke the standard Scheme error handler if a UNIX system call or library function fails. As an alternative, if a specific error action is to be performed by the application, a primitive procedure can be invoked under control of the unix-errval form. In this case, a unique error object is returned if a UNIX function signals an error. The standard UNIX system error message and the UNIX error number are made available to the application in any case. Details of the error handling facilities are described in the section ``Error Functions'' below.

Markup created by unroff 1.0,    September 24, 1996,    net@informatik.uni-bremen.de