The configuration file
The configuration file (called php3.ini in
PHP 3.0, and simply php.ini as of PHP 4.0)
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 version, it happens on
The default location of php.ini is a compile time option (see the FAQ entry), but can be changed
for the CGI and CLI version with the
-c command line switch, see the chapter about using
PHP from the command line. You can also use the
environment variable PHPRC for an additional path to
search for a php.ini file.
The Apache web server changes the directory to root at startup causing
PHP to attempt to read php.ini from the root
filesystem if it exists.
Not every PHP directive is documented below. For a list of all directives,
please read your well commented php.ini file. You may want to view the
latest php.ini here from CVS.
Example 4-1. php.ini example
; any text on a line after an unquoted semicolon (;) is ignored
[php] ; section markers (text within square brackets) are also ignored
; Boolean values can be set to either:
; true, on, yes
; or false, off, no, none
register_globals = off
magic_quotes_gpc = yes
; you can enclose strings in double-quotes
include_path = ".:/usr/local/lib/php"
; backslashes are treated the same as any other character
include_path = ".;c:\php\lib"