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

     ierror - catch Fortran errors

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

     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.


     There is no way to ignore errors.

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