Informix Error -816: Cannot write file (check file permissions).

Reasons / Common Causes

-816 fires when a file named in a preceding command can't be written — per the official guidance, an OS-level write-permission problem is the likely cause.

1. No OS-level write permission on the file (or its containing directory, for a new file), per the official guidance — the direct, likely cause.
2. The file owned by a different OS user, with no group/other permission bit granting write access to the connecting account.

Solutions / Resolution

1. Check the file's permissions, per the official guidance:

   ls -l the_file
   

2. Correct the permissions or ownership as needed, or choose a location the account can write to.
3. Run the program again, per the official guidance, once permissions are corrected.

Examples

Checking permissions

$ ls -l the_file
-r--r--r--  1 otheruser othergroup  ...  the_file

A read-only file owned by a different user explains the failure — correct its permissions or choose a different target file/location.

Diagnostic Checks

1. Check the target file's (or its containing directory's) permissions and ownership against the connecting OS account.

Related Errors / Related Topics

• -817 — "Cannot read file (check file permissions)." The mirror-image error, for a read permission problem rather than write.

An OS-level write-permission problem — check the file's permissions and ownership.