NAME

afopen - open a database

SYNOPSIS

#include af.h

int afopen(const Afopen *r, Afopen_r *rr);

DESCRIPTION

The afopen function opens a database so that it can be accessed for searching, updating, etc.

The argument r specifies a set of options defined by the following structure:

typedef struct {
	char *dbpath;
	char *mode;
	int phrase;
	int stem;
} Afopen;

The dbpath option specifies the database to be opened, consisting of a path name. The file names that make up the database are constructed by appending suffixes to this path name.

The mode option specifies how the database will be accessed:

r

Open database for reading. This opens the database files for searching or other read-only access.

r+

Open database for reading and writing. This is commonly used to add to or modify an existing database.

w+

Open database for reading and writing; the database is created if it does not exist, and otherwise its contents are erased.

RETURN VALUE

This function returns 0 if it exited normally. If an error occurred, it returns -1 and aferrno is set.

If the function exited normally, the structure pointed to by rr is filled in with the following values:

typedef struct {
	Uint2 dbid;
} Afopen_r;

The dbid value is a database descriptor that can be used to refer to the database while it remains open.

ERRORS

In addition to the set of "core" errors, this function can return:

AFEDBLOCK

The database is locked.

AFEOPENLIM

Too many open databases.

AFEVERSION

The database was created with an earlier, incompatible version of this library.