CodeIgniter 打开错误日志

app/config/config.php

/*
 |--------------------------------------------------------------------------
| Error Logging Threshold
|--------------------------------------------------------------------------
|
| If you have enabled error logging, you can set an error threshold to
| determine what gets logged. Threshold options are:
| You can enable error logging by setting a threshold over zero. The
| threshold determines what gets logged. Threshold options are:
|
| 0 = Disables logging, Error logging TURNED OFF
| 1 = Error Messages (including PHP errors)
| 2 = Debug Messages
| 3 = Informational Messages
| 4 = All Messages
|
| For a live site you'll usually only enable Errors (1) to be logged otherwise
| your log files will fill up very fast.
|
*/
$config['log_threshold'] = 4;

默认0 不输出log， 4等级最高

app/logs/log-2022-07-29.php

输出日志用\log_message函数

log_message('error', "Unable to write cache file: ".$cache_path);

 system/core/Common.php

 system/libraries/Log.php

/**
   * Write Log File
   *
   * Generally this function will be called using the global log_message() function
   *
   * @param  string  the error level
   * @param  string  the error message
   * @param  bool  whether the error is a native PHP error
   * @return bool
   */
  public function write_log($level = 'error', $msg, $php_error = FALSE)
  {
    if ($this->_enabled === FALSE)
    {
      return FALSE;
    }

    $level = strtoupper($level);

    if ( ! isset($this->_levels[$level]) OR ($this->_levels[$level] > $this->_threshold))
    {
      return FALSE;
    }

    $filepath = $this->_log_path.'log-'.date('Y-m-d').'.php';
    $message  = '';

    if ( ! file_exists($filepath))
    {
      $message .= "<"."?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed'); ?".">\n\n";
    }

    if ( ! $fp = @fopen($filepath, FOPEN_WRITE_CREATE))
    {
      return FALSE;
    }

    $message .= $level.' '.(($level == 'INFO') ? ' -' : '-').' '.date($this->_date_fmt). ' --> '.$msg."\n";

    flock($fp, LOCK_EX);
    fwrite($fp, $message);
    flock($fp, LOCK_UN);
    fclose($fp);

    @chmod($filepath, FILE_WRITE_MODE);
    return TRUE;
  }

CodeIgniter phpstorm自动补全

@property \CI_Input input

<?php

/**
 * @property \MY_Loader load
 * @property \CI_Input input
 */
class Common extends CI_Controller {
    // ...
}