How to check particular php extension installed in linux?

This command shows the extension installed or not
$ php --re extensionname

example :
$ php --re intl
Exception: Extension intl does not exist

If exists then display the extension like below with version and its contents

Extension [
extension #46 intl version 1.1.0 ] {

- INI {
Entry [ intl.default_locale ]
Current = ''
}
Entry [ intl.error_level ]
Current = '0'
}
}

- Constants [171] {
Constant [ integer INTL_MAX_LOCALE_LEN ] { 80 }
Constant [ string INTL_ICU_VERSION ] { 4.8.1.1 }
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