Zend Extension Manager

The Zend Extension Manager (ZEM) manges all the Zend product line extensions.
Because every Zend extension is compiled for each PHP version, the ZEM selects the proper extension version, depending on the PHP runtime. In addition, the ZEM exposes the C language API that reflects all the information for the managed extensions and is responsible for managing the licences of these extensions
Every INI directive of form 'zend_extension_manager.dir.xxx=yyy' string, where 'xxx' is a reserved name (see below), is considered to be an extension that should be managed. The 'xxx' is called 'extensionId' and 'yyy' is treated as a path to the subtree, where all the extension compilations are located. The ZEM always selects the proper version
Because the loading order of extensions is significant, there is a special 'load order' file that specifies the loading order of managed extensions. If the file is not supplied, the declaration order in the PHP INI files is significant
All Zend product line extensions can only be loaded by the ZEM.

External Configuration File: load order file

The load order file specifies the extension loading order. This file contains plain text with a single 'extensionId' per line. The extension IDs are not necessarily found in php.ini files. The nonexistent IDs are not considered, but may be reserved for future use (i.e., system upgrade)
This file should not be modified.
Parameters:

INI Directives:

zend_extension_manager.log_verbosity_level
Log message verbosity level.
The default level is usually set to 1, which includes very important information messages, errors and warnings.
Switch the level to 2 to see the notices. Higher levels (up to 5) are reserved for debug purposes only.

IMPORTANT: The ZEM is absolutely required to load any Zend extension from the Zend product line. There is other way to load Zend extensions besides using the ZEM.
Default value(s):
1:
Type: int
Measurement units:
Available since: 3.6

zend_extension_manager.load_order_file
The path to the location of the load file. The load file contains the information about the extensions' loading order
The file should be in plain text. Each line should list only one extensionId. The order of lines (extensionIds) determines the the order of loading the appropriate extensions. If a particular extensionId is not managed in any INI file, the ID is skipped.
Default value(s):
zem_order:
Type: string
Measurement units:
Available since: 3.6

zend_extension_manager.activate_signal_handlers
UNIX only: Activates SIGSEGV and SIGABRT signal handlers.
If enabled, the stack trace is printed when the signal is received. This directive can be combined with 'zend_extension_manager.wait_for_debugger'.
Default value(s):
false:
Type: boolean
Measurement units:
Available since: 3.6

zend_extension_manager.wait_for_debugger
UNIX only: Automatically pauses the process received by SIGSEGV and SIGABRT.
If enabled, the process is paused when the signal is received, so that 'gdb' can be easily attached. 'zend_extension_manager.activate_signal_handlers' must be enabled.
Default value(s):
false:
Type: boolean
Measurement units:
Available since: 3.6