# Misc（核心） - [预定义常量](https://www.php.net/manual/zh/misc.constants.php) - [杂项 函数](https://www.php.net/manual/zh/ref.misc.php) - [connection\_aborted](https://www.php.net/manual/zh/function.connection-aborted.php)— 检查客户端是否已经断开 - [connection\_status](https://www.php.net/manual/zh/function.connection-status.php)— 返回连接的状态位 - [constant](https://www.php.net/manual/zh/function.constant.php)— 返回一个常量的值 - [define](https://www.php.net/manual/zh/function.define.php)— 定义一个常量 - [defined](https://www.php.net/manual/zh/function.defined.php)— 检查某个名称的常量是否存在 - [die](https://www.php.net/manual/zh/function.die.php)— 等同于 exit - [eval](https://www.php.net/manual/zh/function.eval.php)— 把字符串作为PHP代码执行 - [exit](https://www.php.net/manual/zh/function.exit.php)— 输出一个消息并且退出当前脚本 - [get\_browser](https://www.php.net/manual/zh/function.get-browser.php)— 获取浏览器具有的功能 - [\_\_halt\_compiler](https://www.php.net/manual/zh/function.halt-compiler.php)— 中断编译器的执行 - [highlight\_file](https://www.php.net/manual/zh/function.highlight-file.php)— 语法高亮一个文件 - [highlight\_string](https://www.php.net/manual/zh/function.highlight-string.php)— 字符串的语法高亮 - [hrtime](https://www.php.net/manual/zh/function.hrtime.php)— Get the system's high resolution time - [ignore\_user\_abort](https://www.php.net/manual/zh/function.ignore-user-abort.php)— 设置客户端断开连接时是否中断脚本的执行 - [pack](https://www.php.net/manual/zh/function.pack.php)— 将数据打包成二进制字符串 - [php\_check\_syntax](https://www.php.net/manual/zh/function.php-check-syntax.php)— 检查PHP的语法（并执行）指定的文件 - [php\_strip\_whitespace](https://www.php.net/manual/zh/function.php-strip-whitespace.php)— 返回删除注释和空格后的PHP源码 - [sapi\_windows\_cp\_conv](https://www.php.net/manual/zh/function.sapi-windows-cp-conv.php)— Convert string from one codepage to another - [sapi\_windows\_cp\_get](https://www.php.net/manual/zh/function.sapi-windows-cp-get.php)— Get process codepage - [sapi\_windows\_cp\_is\_utf8](https://www.php.net/manual/zh/function.sapi-windows-cp-is-utf8.php)— Indicates whether the codepage is UTF-8 compatible - [sapi\_windows\_cp\_set](https://www.php.net/manual/zh/function.sapi-windows-cp-set.php)— Set process codepage - [sapi\_windows\_generate\_ctrl\_event](https://www.php.net/manual/zh/function.sapi-windows-generate-ctrl-event.php)— Send a CTRL event to another process - [sapi\_windows\_set\_ctrl\_handler](https://www.php.net/manual/zh/function.sapi-windows-set-ctrl-handler.php)— Set or remove a CTRL event handler - [sapi\_windows\_vt100\_support](https://www.php.net/manual/zh/function.sapi-windows-vt100-support.php)— Get or set VT100 support for the specified stream associated to an output buffer of a Windows console. - [show\_source](https://www.php.net/manual/zh/function.show-source.php)— 别名 highlight\_file - [sleep](https://www.php.net/manual/zh/function.sleep.php)— 延缓执行 - [sys\_getloadavg](https://www.php.net/manual/zh/function.sys-getloadavg.php)— 获取系统的负载（load average） - [time\_nanosleep](https://www.php.net/manual/zh/function.time-nanosleep.php)— 延缓执行若干秒和纳秒 - [time\_sleep\_until](https://www.php.net/manual/zh/function.time-sleep-until.php)— 使脚本睡眠到指定的时间为止。 - [uniqid](https://www.php.net/manual/zh/function.uniqid.php)— 生成一个唯一ID - [unpack](https://www.php.net/manual/zh/function.unpack.php)— Unpack data from binary string - [usleep](https://www.php.net/manual/zh/function.usleep.php)— 以指定的微秒数延迟执行