The global variable
gdbm_errno (see gdbm_errno)
keeps the error code of the most recent error encountered by GDBM
To convert this code to human-readable string, use the following function:
Converts errno (which is an integer value) into a human-readable descriptive text. Returns a pointer to a static string. The caller must not free the returned pointer or alter the string it points to.
Detailed information about the most recent error that occurred while
operating on a GDBM file is stored in the
itself. To retrieve it, the following functions are provided:
Returns the code of the most recent error encountered when operating on dbf.
Returns the value of the system
errno variable associated with
the most recent error.
Notice, that not all GDBM errors have an associated system error code. The following are the ones that have:
For other errors,
gdbm_last_syserr will return 0.
1, if system
errno value should be checked to get more
info on the error described by GDBM code err.
To get a human-readable description of the recent error for a
particular database file, use the
Returns textual description of the most recent error encountered when
operating on the database dbf. The resulting string is often
more informative than what would be returned by
gdbm_strerror(gdbm_last_errno(dbf)). In particular, if
there is a system error associated with the recent failure, it will be
described as well.
Clears the error state for the database dbf. Normally, this function is called upon the entry to any GDBM function.
Certain errors (such as write error when saving stored key) can leave
database file in inconsistent state (see Database consistency).
When such a critical error occurs, the database file is marked as
needing recovery. Subsequent calls to any GDBM functions for that
database file (except
gdbm_recover), will return immediately
with GDBM error value
GDBM_NEED_RECOVERY. Additionally, the
following function can be used to check the state of the database file:
1 if the database file dbf is in inconsistent
state and needs recovery.
To restore structural consistency of the database, use the
gdbm_recover function (see Recovery).
Crash tolerance provides a better way of recovery, because it restores both structural and logical consistency. See Crash Tolerance, for a detailed discussion,