Fortran User's Guide

I/O Error Messages (f77)

The error messages in this section are generated by the Fortran 77 I/O library. The error numbers are returned in the IOSTAT variable if the ERR return is taken.

For example, the following program tries to do an unformatted write to a file opened for formatted output:

      WRITE( 6 ) 1 
      END

and produces error messages like the following:

sue: [1003] unformatted io not allowed
logical unit 6, named 'stdout'
lately: writing sequential unformatted external IO

The following error messages are generated. These same messages are also documented at the end of the man page perror(3F).

If the error number is less than 1000, then it is a system error. See intro (2).

Table A-1 f77 Runtime I/O Messages


Error	Message
`1000`	`error in format` Read the error message output for the location of the error in the format. It can be caused by more than 10 levels of nested parentheses or an extremely long format statement.
`1001`	`illegal unit number` It is illegal to close logical unit 0. Negative unit numbers are not allowed. The upper limit is 2³¹ - 1.
`1002`	`formatted io not allowed` The logical unit was opened for unformatted I/O.
`1003`	`unformatted io not allowed` The logical unit was opened for formatted I/O.
`1004`	`direct io not allowed` The logical unit was opened for sequential access, or the logical record length was specified as 0.
`1005`	`sequential io not allowed` The logical unit was opened for direct access I/O.
`1006`	`can't backspace file` You cannot do a `seek` on the file associated with the logical unit; therefore, you cannot backspace. The file may be a `tty` device or a pipe.
`1007`	`off beginning of record` You tried to do a left tab to a position before the beginning of an internal input record.
`1008`	`can't stat file` The system cannot return status information about the file. Perhaps the directory is unreadable.
`1009`	`no * after repeat count` Repeat counts in list-directed I/O must be followed by an `*` with no blank spaces.
1010	`off end of record` A formatted write tried to go beyond the logical end-of-record. An unformatted read or write also causes this
1011	<Not used>
1012	`incomprehensible list input` List input has to be as specified in the declaration.
1013	`out of free space` The library dynamically creates buffers for internal use. You ran out of memory for them; that is, your program is too big.
1014	`unit not connected` The logical unit was not open.
1015	`read unexpected character` Certain format conversions cannot tolerate nonnumeric data.
1016	`illegal logical input field` logical data must be T or F.
1017	`'new' file exists` You tried to open an existing file with status='new'.
1018	`can't find 'old' file` You tried to open a nonexistent file with status='old'.
1019	`unknown system error` This error should not happen, but..
1020	`requires seek ability` Attempted a `seek` on a file that does not allow it. I/O operation requiring a `seek` are direct access, sequential unformatted I/O, and tabbing left.
1021	`illegal argument` Certain arguments to open and related functions are checked for legitimacy. Often only nondefault forms are checked
1022	`negative repeat count` The repeat count for list-directed input must be a positive integer.
1023	`illegal operation for unit` Attempted an I/O operation that is not possible for the device associated with the logical unit. You get this error if you try to read past end-of-tape, or end-of-file.
1024	<Not used>
1025	`incompatible specifiers in open` Attempted to open a file with the 'new' option and the access='append' option, or some other invalid combination.
1026	`illegal input for namelist` A namelist read encountered an invalid data item.
1027	`error in FILEOPT parameter` The `FILEOPT` string in an `OPEN` statement has bad syntax.
1028	`WRITE to readonly file` Attempt to write on a unit that was opened for reading only.
1029	`READ from writeonly file` Attempt to read from a unit that was opened for writing only.
1030	`overflow converting numeric input` Integer input data is too large for the corresponding input variable
1032	`exponent overflow on numeric input` The floating-point input data is too large to be represented by the corresponding input variable.