IO.ERR - output error message related to an I/O unit.

Usage:

B:
   io.err( unit [, errnum [, format, arg1, arg2, ...]] );

C:
   #equate io_err io.err
   void io_err(FILE *unit [, int errnum,
               [const char *format, ... ]] );

Where:

unit: is a unit number or FILE* pointer indicating a unit on which an error occurred.
errnum: is an error number indicating the nature of the error. If this is omitted, IO.ERR outputs the posted message for the unit (if any).
format: is a PRINTF-style format string giving the error message. If this is omitted, IO.ERR outputs the posted error message for the specified unit, provided that the error number of the posted error message matches "errnum".
arg1, arg2, ...: are arguments to be filled into placeholders in the "format" string.

Description:

IO.ERR outputs an error message to the standard error unit. This message describes an error encountered on "unit". The format of the message output by IO.ERR is

filename: location: message

where "filename" is the name of the associated with "unit", "location" is the current read/write location on the unit, and "message" is the text of the error message.

You may specify the text of the error message in the call to IO.ERR by specifying a format string and arguments. If you do not specify such a message, IO.ERR generates its own, using the following rules:

If you do not specify an "errnum" and the unit is in an error state, IO.ERR prints the posted error message.
If you do not specify an "errnum" and the unit has no posted error message, IO.ERR does not output a message.
If you specify an "errnum", IO.ERR sets the unit into an error state. IO.ERR prints out an error message if the options specified when the unit was opened request such a message.

For more on posted error messages, see "expl b lib .epost".

IO.ERR - output error message related to an I/O unit.

Usage:

Where:

Description:

See Also: