Description
resource 
yaz_connect ( string zurl [, mixed options])
     This function returns a connection resource on success, zero on
     failure.
    
     yaz_connect() prepares for a connection to a
     Z39.50 server. The zurl argument takes the form
     host[:port][/database]. If port is omitted, port 210 is used. If
     database is omitted Default is used.
     This function is non-blocking and does not attempt to establish
     a connection  - it merely prepares a connect to be performed later when
     yaz_wait() is called.
    
     If the second argument, options, is given as
     a string it is treated as the Z39.50 V2 authentication string
     (OpenAuth).
    
     If options is given as an array the contents
     of the array serves as options. Note that array options are only
     supported for PHP 4.1.0 and later.
    
yaz_connect() options
- user
- Username for authentication. 
- group
- Group for authentication. 
- password
- Password for authentication. 
- cookie
- Cookie for session (YAZ proxy). 
- proxy
- Proxy for connection (YAZ proxy). 
- persistent
- A boolean. If TRUE the connection is persistent; If FALSE
        the connection is not persistent. By default connections are persistent.
        
- piggyback
- A boolean. If TRUE piggyback is enabled for searches; If
        FALSE piggyback is disabled. By default piggyback is enabled. Enabling
        piggyback is more efficient and usually saves a network-round-trip for
        first time fetches of records. However, a few Z39.50 servers do not
        support piggyback or they ignore element set names. For those, piggyback
        should be disabled.
        
- charset
- A string that specifies character set to be used
        in Z39.50 language and character set negotiation.
        Use strings such as:
        ISO-8859-1, UTF-8, 
        UTF-16.
        - 
        Most Z39.50 servers do not support this feature (and thus, 
        this is ignored). Many servers use the ISO-8859-1
        encoding for queries and messages. MARC21/USMARC records are not
        affected by this setting.
        
     
注: The use of a proxy often improves performance. A Z39.50 proxy
       is part of the free YAZ++ package.