inotify_init

    (PECL inotify >= 0.1.2)

    inotify_init — 初始化 inotify 实例

    说明

    inotify_init(): resource|false

    初始化 inotify_add_watch() 使用的 inotify 实例

    参数

    此函数没有参数。

    返回值

    返回资源流或发生错误时返回 false。

    示例

    示例 #1 inotify 使用示例

    <?php
    // Open an inotify instance
    $fd = inotify_init();

    // Watch __FILE__ for metadata changes (e.g. mtime)
    $watch_descriptor = inotify_add_watch($fd, __FILE__, IN_ATTRIB);

    // generate an event
    touch(__FILE__);

    // Read events
    $events = inotify_read($fd);
    print_r($events);

    // The following methods allows to use inotify functions without blocking on inotify_read():

    // - Using stream_select() on $fd:
    $read = array($fd);
    $write = null;
    $except = null;
    stream_select($read,$write,$except,0);

    // - Using stream_set_blocking() on $fd
    stream_set_blocking($fd, 0);
    inotify_read($fd); // Does no block, and return false if no events are pending

    // - Using inotify_queue_len() to check if event queue is not empty
    $queue_len = inotify_queue_len($fd); // If > 0, inotify_read() will not block

    // Stop watching __FILE__ for metadata changes
    inotify_rm_watch($fd, $watch_descriptor);

    // Close the inotify instance
    // This may have closed all watches if this was not already done
    fclose($fd);

    ?>

    以上示例的输出类似于：

    array(
  array(
    'wd' => 1,     // Equals $watch_descriptor
    'mask' => 4,   // IN_ATTRIB bit is set
    'cookie' => 0, // unique id to connect related events (e.g. 
                   // IN_MOVE_FROM and IN_MOVE_TO events)
    'name' => '',  // the name of a file (e.g. if we monitored changes
                   // in a directory)
  ),
);

    参见

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    11
    david dot schueler at tel-billig dot de
    14 years ago
    Example for tailing a file (like tail -f) using inotify.<?php/** * Tail a file (UNIX only!) * Watch a file for changes using inotify and return the changed data * * @param string $file - filename of the file to be watched * @param integer $pos - actual position in the file * @return string */function tail($file,&$pos) {    // get the size of the file    if(!$pos) $pos = filesize($file);    // Open an inotify instance    $fd = inotify_init();    // Watch $file for changes.    $watch_descriptor = inotify_add_watch($fd, $file, IN_ALL_EVENTS);    // Loop forever (breaks are below)    while (true) {        // Read events (inotify_read is blocking!)        $events = inotify_read($fd);        // Loop though the events which occured        foreach ($events as $event=>$evdetails) {            // React on the event type            switch (true) {                // File was modified                case ($evdetails['mask'] & IN_MODIFY):                    // Stop watching $file for changes                    inotify_rm_watch($fd, $watch_descriptor);                    // Close the inotify instance                    fclose($fd);                    // open the file                    $fp = fopen($file,'r');                    if (!$fp) return false;                    // seek to the last EOF position                    fseek($fp,$pos);                    // read until EOF                    while (!feof($fp)) {                        $buf .= fread($fp,8192);                    }                    // save the new EOF to $pos                    $pos = ftell($fp); // (remember: $pos is called by reference)                    // close the file pointer                    fclose($fp);                    // return the new data and leave the function                    return $buf;                    // be a nice guy and program good code ;-)                    break;                    // File was moved or deleted                case ($evdetails['mask'] & IN_MOVE):                case ($evdetails['mask'] & IN_MOVE_SELF):                case ($evdetails['mask'] & IN_DELETE):                case ($evdetails['mask'] & IN_DELETE_SELF):                    // Stop watching $file for changes                    inotify_rm_watch($fd, $watch_descriptor);                    // Close the inotify instance                    fclose($fd);                    // Return a failure                    return false;                    break;            }        }    }}// Use it like that:$lastpos = 0;while (true) {    echo tail($file,$lastpos);}?>
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