What does errno 88 (EILSEQ) in Solaris mean?

EILSEQ

Character conversion and multibyte input

EILSEQ is Solaris errno 88 (Illegal byte sequence.). Solaris rejected a byte sequence that is invalid for the expected character encoding.

Preserve the original byte sequence and the locale or conversion descriptor used by the failing call. Replacing invalid bytes before logging them makes it harder to distinguish corrupt input from a caller using the wrong character encoding.

What to check

• Check the active locale and codeset used by the conversion function.
• Preserve the original bytes when logging; converting them again can hide the offending sequence.
• Distinguish invalid byte sequences from range errors such as EOVERFLOW.

References

• Oracle Solaris intro(2): error numbers
• illumos errno.h definitions
• POSIX errno.h