运行时配置
这些函数的行为受 php.ini 中的设置影响。
| 名字 | 默认 | 可修改范围 | 更新日志 | 
|---|---|---|---|
| define_syslog_variables | "0" | PHP_INI_ALL | 在PHP5.3.0中不推荐使用。在PHP5.4.0中删除 | 
资源类型
此扩展名定义返回的文件指针资源fsockopen()pfsockopen()
预定义常量
下列常量作为 PHP 核心的一部分总是可用的。
| 常数 | 描述 | 
|---|---|
| LOG_CONS | if there is an error while sending data to the system logger, write directly to the system console | 
| LOG_NDELAY | open the connection to the logger immediately | 
| LOG_ODELAY | (default) delay opening the connection until the first message is logged | 
| LOG_NOWAIT | |
| LOG_PERROR | print log message also to standard error | 
| LOG_PID | include PID with each message | 
| 常数 | 描述 | 
|---|---|
| LOG_AUTH | security/authorization messages (use LOG_AUTHPRIV instead in systems where that constant is defined) | 
| LOG_AUTHPRIV | security/authorization messages (private) | 
| LOG_CRON | clock daemon (cron and at) | 
| LOG_DAEMON | other system daemons | 
| LOG_KERN | kernel messages | 
| LOG_LOCAL0 ... LOG_LOCAL7 | reserved for local use, these are not available in Windows | 
| LOG_LPR | line printer subsystem | 
| LOG_MAIL | mail subsystem | 
| LOG_NEWS | USENET news subsystem | 
| LOG_SYSLOG | messages generated internally by syslogd | 
| LOG_USER | generic user-level messages | 
| LOG_UUCP | UUCP subsystem | 
| 常数 | 描述 | 
|---|---|
| LOG_EMERG | system is unusable | 
| LOG_ALERT | action must be taken immediately | 
| LOG_CRIT | critical conditions | 
| LOG_ERR | error conditions | 
| LOG_WARNING | warning conditions | 
| LOG_NOTICE | normal, but significant, condition | 
| LOG_INFO | informational message | 
| LOG_DEBUG | debug-level message | 
| 常数 | 描述 | 
|---|---|
| DNS_A | IPv4 Address Resource | 
| DNS_CAA | Certification Authority Authorization Resource (available as of PHP 7.0.16 and 7.1.2) | 
| DNS_MX | Mail Exchanger Resource | 
| DNS_CNAME | Alias (Canonical Name) Resource | 
| DNS_NS | Authoritative Name Server Resource | 
| DNS_PTR | Pointer Resource | 
| DNS_HINFO | Host Info Resource (See IANA's » Operating System Names for the meaning of these values) | 
| DNS_SOA | Start of Authority Resource | 
| DNS_TXT | Text Resource | 
| DNS_ANY | Any Resource Record. On most systems this returns all resource records, however it should not be counted upon for critical uses. Try DNS_ALL instead. | 
| DNS_AAAA | IPv6 Address Resource | 
| DNS_ALL | Iteratively query the name server for each available record type. | 
