There are a few ways to locate php.ini file by command line on Linux Ubuntu, Linux Mint, and other Linux distributions. Some of the options showed here are also compatible with Windows, specially usin WSL.

What is php.ini

The php.ini file is the configuration file that is read when PHP starts up. For the server module versions of PHP, this happens only once when the web server is started. For the CGI and CLI versions, it happens on every invocation.

It is the main place where you declare changes to your PHP settings. The server is already configured with standard settings for PHP, which your site or application will use by default. Unless you need to change one or more settings, there is no need to create or modify a php.ini file.

Where is php.ini file located by default

The php.ini file is searched for in these locations (in order):

  • SAPI module specific location (PHPIniDir directive in Apache 2, -c command line option in CGI and CLI)

  • The PHPRC environment variable.

  • The location of the php.ini file can be set for different versions of PHP. The root of the registry keys depends on 32- or 64-bitness of the installed OS and PHP. For 32-bit PHP on a 32-bit OS or a 64-bit PHP on a 64-bit OS use [(HKEY_LOCAL_MACHINE\SOFTWARE\PHP] for 32-bit version of PHP on a 64-bit OS use [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\PHP]] instead. For same bitness installation the following registry keys are examined in order: [HKEY_LOCAL_MACHINE\SOFTWARE\PHP\x.y.z], [HKEY_LOCAL_MACHINE\SOFTWARE\PHP\x.y] and [HKEY_LOCAL_MACHINE\SOFTWARE\PHP\x], where x, y and z mean the PHP major, minor and release versions. For 32 bit versions of PHP on a 64 bit OS the following registry keys are examined in order: [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6421Node\PHP\x.y.z], [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6421Node\PHP\x.y] and [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6421Node\PHP\x], where x, y and z mean the PHP major, minor and release versions. If there is a value for IniFilePath in any of these keys, the first one found will be used as the location of the php.ini (Windows only).

  • [HKEY_LOCAL_MACHINE\SOFTWARE\PHP] or [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\PHP], value of IniFilePath (Windows only).

  • Current working directory (except CLI).

  • The web server’s directory (for SAPI modules), or directory of PHP (otherwise in Windows).

  • Windows directory (C:\windows or C:\winnt) (for Windows), or –with-config-file-path compile time option.

If php-SAPI.ini exists (where SAPI is the SAPI in use, so, for example, php-cli.ini or php-apache.ini), it is used instead of php.ini. The SAPI name can be determined with php_sapi_name() (returns the type of interface between web server and PHP).

How can I find the php.ini file from command line

php –ini

There is a simple option called --ini that you can use when run php command:

php --ini

The output will show where is the php.ini used by command line, as well additional scanned configuration files:

Configuration File (php.ini) Path: /etc/php/7.4/cli
Loaded Configuration File:         /etc/php/7.4/cli/php.ini
Scan for additional .ini files in: /etc/php/7.4/cli/conf.d
Additional .ini files parsed:      /etc/php/7.4/cli/conf.d/10-mysqlnd.ini,
/etc/php/7.4/cli/conf.d/10-pdo.ini,
/etc/php/7.4/cli/conf.d/15-xml.ini,
/etc/php/7.4/cli/conf.d/20-bcmath.ini,
/etc/php/7.4/cli/conf.d/20-exif.ini,
/etc/php/7.4/cli/conf.d/20-gd.ini,
/etc/php/7.4/cli/conf.d/20-gettext.ini,
/etc/php/7.4/cli/conf.d/20-iconv.ini,
/etc/php/7.4/cli/conf.d/20-intl.ini,
/etc/php/7.4/cli/conf.d/20-json.ini,
/etc/php/7.4/cli/conf.d/20-mbstring.ini,
/etc/php/7.4/cli/conf.d/20-mysqli.ini,
/etc/php/7.4/cli/conf.d/20-pdo_mysql.ini,
/etc/php/7.4/cli/conf.d/20-pdo_pgsql.ini,
/etc/php/7.4/cli/conf.d/20-pdo_sqlite.ini,
/etc/php/7.4/cli/conf.d/20-pgsql.ini,
/etc/php/7.4/cli/conf.d/20-redis.ini,
/etc/php/7.4/cli/conf.d/20-simplexml.ini,
/etc/php/7.4/cli/conf.d/20-sockets.ini,
/etc/php/7.4/cli/conf.d/20-sqlite3.ini,
/etc/php/7.4/cli/conf.d/20-xmlreader.ini,
/etc/php/7.4/cli/conf.d/20-xmlwriter.ini,
/etc/php/7.4/cli/conf.d/20-xsl.ini,
/etc/php/7.4/cli/conf.d/20-zip.ini,
/etc/php/7.4/cli/conf.d/xdebug.ini

php-config –ini-dir

Using php-config you can list only the path where the main PHP configuration file is located:

php-config --ini-dir

The output is something like:

/etc/php/7.4/cli/conf.d

php -i and grep

The command php -i shows a complete phpinfo() result. You can find all configurations and apply grep command to filter only the .ini configuration file:

php -i | grep 'Configuration File'

Or in Windows you can use find instead:

php -i | find/i"configuration file"

The result to both command will be similar to:

Configuration File (php.ini) Path => /etc/php/7.4/cli
Loaded Configuration File => /etc/php/7.4/cli/php.ini

Finally you can use grep to filter all lines of the phpinfo() that shows .ini:

php -i | grep "\.ini"

The output will be similar to php -i command:

Configuration File (php.ini) Path: /etc/php/7.4/cli
Loaded Configuration File:         /etc/php/7.4/cli/php.ini
Scan for additional .ini files in: /etc/php/7.4/cli/conf.d
Additional .ini files parsed:      /etc/php/7.4/cli/conf.d/10-mysqlnd.ini,
/etc/php/7.4/cli/conf.d/10-pdo.ini,
/etc/php/7.4/cli/conf.d/15-xml.ini,
/etc/php/7.4/cli/conf.d/20-bcmath.ini,
/etc/php/7.4/cli/conf.d/20-exif.ini,
/etc/php/7.4/cli/conf.d/20-gd.ini,
/etc/php/7.4/cli/conf.d/20-gettext.ini,
/etc/php/7.4/cli/conf.d/20-iconv.ini,
/etc/php/7.4/cli/conf.d/20-intl.ini,
/etc/php/7.4/cli/conf.d/20-json.ini,
/etc/php/7.4/cli/conf.d/20-mbstring.ini,
/etc/php/7.4/cli/conf.d/20-mysqli.ini,
/etc/php/7.4/cli/conf.d/20-pdo_mysql.ini,
/etc/php/7.4/cli/conf.d/20-pdo_pgsql.ini,
/etc/php/7.4/cli/conf.d/20-pdo_sqlite.ini,
/etc/php/7.4/cli/conf.d/20-pgsql.ini,
/etc/php/7.4/cli/conf.d/20-redis.ini,
/etc/php/7.4/cli/conf.d/20-simplexml.ini,
/etc/php/7.4/cli/conf.d/20-sockets.ini,
/etc/php/7.4/cli/conf.d/20-sqlite3.ini,
/etc/php/7.4/cli/conf.d/20-xmlreader.ini,
/etc/php/7.4/cli/conf.d/20-xmlwriter.ini,
/etc/php/7.4/cli/conf.d/20-xsl.ini,
/etc/php/7.4/cli/conf.d/20-zip.ini,
/etc/php/7.4/cli/conf.d/xdebug.ini

Conclusions

There are several ways to find php.ini file and other configurations files of your PHP installation using native commands on terminal.