Several configuration file functions of php

I never paid attention to it before. I heard it from my colleague today and took a look immediately. It is very effective.
The configuration function of PHP is several ini_* functions, mainly for the control of configuration files. There are actually four functions: ini_get, ini_set, ini_get_all, and ini_restore. Personally, the most useful ones are ini_set and ini_get.

* ini_get(): Get the option value of the configuration file

This function is believed to be used by many people. It is to get the value of an option in the configuration file. If it is a true value, it returns 1, if it is a false value, it returns 0. , the string returns the string.
For example, the example in the manual:
/*
Our php.ini contains the following settings:

display_errors = On
register_globals = Off
post_max_size = 8M
*/
echo 'display_errors = ' . ini_get( 'display_errors') . 'n'; //Whether display errors are turned on
echo 'register_globals = ' . ini_get('register_globals') . 'n';//Whether global variables are turned on
echo 'post_max_size = ' . ini_get('post_max_size ') . 'n';//The maximum file size that can be submitted
echo 'post_max_size 1 = ' . (ini_get('post_max_size') 1) . 'n';
?>

Output:
display_errors = 1
register_globals = 0
post_max_size = 8M
post_max_size 1 = 9

This function is mainly to obtain the configuration file, which can facilitate a lot of operations for you. For example, you want to control string filtering, but you don’t know whether magic_quotes_gpc is turned on, so you can write a function like this:

/* String filter function*/
function stringFilter($str)
{
if (ini_get( 'magic_quotes_gpc)') {
return $str;
} else {
return addslashes($str);
}
}
Of course, if you have no way of knowing whether your global variable is open, you can also customize a function like this:

/* Variable detection function*/
function getGetVar($var)
{
if (ini_set('register_gobals')) {
return $var;
} else {
return $_GET['var'];
}
}
Of course, you can use it for many purposes, and you will slowly understand it yourself.

* ini_set function: Set certain variable values ​​​​in php.ini

This function is to set the value in the option. It takes effect after the function is executed. When the script ends, this setting also becomes invalid. Not all options can be set by the function. Specific values ​​​​can be set, you can view the list in the manual.
It means you can set the option value in php.ini. For example, the display_error option is closed, but you want to display the error information in the program to facilitate your debugging the program, then you can use this function:

ini_set('display_errors', 'On ');

Then the program on your page will display error information, and you can also use error_reporting to set the level of error information displayed.
If you need to increase the script execution time, you can set:

ini_set('max_execution_time', '180');

Then the script execution time will change from the default 30 seconds to 180 seconds. Of course, you can also use set_time_limit () to set.
In fact, it is very good if you use ini_set and ini_get together. For example, if you want to add your own include file path to the configuration file, but do you have permission to change php.ini, then you can combine the two functions: