    IERROR(III)                  10/29/73                 IERROR(III)

    NAME
         ierror - catch Fortran errors

    SYNOPSIS
         if ( ierror ( errno ) .ne. 0 ) goto label

    DESCRIPTION
         Ierror provides a way of detecting errors during the running
         of a Fortran program.  Its argument is a run-time error num-
         ber such as enumerated in fc(I).

         When  ierror  is called, it returns a 0 value; thus the goto
         statement in the synopsis is  not  executed.   However,  the
         routine  stores  inside itself the call point and invocation
         level.  If and when the indicated error occurs, a return  is
         simulated  from  ierror with a non-zero value; thus the goto
         (or other statement) is executed.  It is a ghastly error  to
         call  ierror  from  a  subroutine which has already returned
         when the error occurs.

         This routine is essentially tailored to catching end-of-file
         situations.  Typically it is called just before the start of
         the loop which reads the input file, and the goto jumps to a
         graceful termination of the program.

         There  is a limit of 5 on the number of different error num-
         bers which can be caught.

    SEE ALSO
         fc(I)

    BUGS
         There is no way to ignore errors.

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