Informix Error -4823: The file associated with the file descriptor may not be opened.

Reasons / Common Causes

-4823 fires when a file descriptor used in a file I/O operation isn't associated with an open file — per the official guidance.

1. The file was already closed, per the official guidance — the first named cause.
2. The file descriptor variable was changed elsewhere in the program, per the official guidance — the second named cause.

Solutions / Resolution

1. Revisit the program logic, per the official guidance, to find where the file was closed prematurely or the descriptor variable was overwritten.

Examples

Reusing a descriptor after closing it

CALL f.close(fd)
CALL f.read(fd, buf)
-- -4823: fd was already closed above

Diagnostic Checks

1. Trace the file descriptor variable's lifecycle — where it's opened, used, and closed — to find where it was closed early or reassigned.

Related Errors / Related Topics

• -4822 — "The file file_name cannot be closed." A related file I/O failure, about the close operation itself failing rather than the descriptor being stale afterward.
• -4830 — "The variable var_name is not of type INTEGER or SMALLINT. It cannot be used as a file descriptor." A related file-descriptor error, about the variable's type rather than its open/closed state.

A file descriptor isn't associated with an open file — trace its lifecycle for a premature close or reassignment.