Php/docs/function.dba-popen
dba_popen
(PHP 4, PHP 5, PHP 7)
dba_popen — Open database persistently
说明
dba_popen
( string $path
, string $mode
[, string $handler
], mixed ...$args
) : resource|false
dba_popen() establishes a persistent database instance
for path
with mode
using
handler
.
参数
path
Commonly a regular path in your filesystem.
mode
It is
r
for read access,w
for read/write access to an already existing database,c
for read/write access and database creation if it doesn't currently exist, andn
for create, truncate and read/write access.handler
The name of the handler which shall be used for accessing
path
. It is passed all optional parameters given to dba_popen() and can act on behalf of them.args
Optional string parameters which are passed to the driver.
The
cdb
,cdb_make
,flatfile
,inifile
,qdbm
andtcadb
drivers do not support additional parameters.The
db1
,db2
,db3
,db4
,dbm
,gdbm
, andndbm
drivers supports a single additional parameter$filemode
, which has the same meaning as the$mode
parameter of chmod(), and defaults to0644
.The
lmdb
driver accepts two additional parameters. The first allows to specify the$filemode
(see description above), and the second to specify the$mapsize
, where the value should be a multiple of the page size of the OS, or zero, to use the default mapsize. The$mapsize
parameter is supported as of PHP 7.3.14 and 7.4.2, respectively.
返回值
Returns a positive handle on success 或者在失败时返回 false
.