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 version, it happens on every invocation.
When using PHP as an Apache module, you can also change the configuration settings using directives in Apache configuration files and .htaccess files.
With PHP 3.0, there are Apache directives that correspond to each configuration setting in the php3.ini name, except the name is prefixed by "php3_".
With PHP 4.0, there are just a few Apache directives that allow you to change the PHP configuration settings.
- php_value name value
This sets the value of the specified variable.
- php_flag name on|off
This is used to set a Boolean configuration option.
- php_admin_value name value
This sets the value of the specified variable. "Admin" configuration settings can only be set from within the main Apache configuration files, and not from .htaccess files.
- php_admin_flag name on|off
This is used to set a Boolean configuration option.
You can view the settings of the configuration values in the output of phpinfo(). You can also access the values of individial configuration settings using get_cfg_var().
- allow_url_fopen boolean
This option enables the URL-aware fopen wrappers that enable accessing URL object like files. Default wrappers are provided for the access of remote files using the ftp or http protocol, some extensions like zlib may register additional wrappers.
Note: This option was introduced immediately after the release of version 4.0.3. For versions up to and including 4.0.3 you can only disable this feature at compile time by using the configuration switch --disable-url-fopen-wrapper.
- asp_tags boolean
Enables the use of ASP-like <% %> tags in addition to the usual <?php ?> tags. This includes the variable-value printing shorthand of <%= $value %>. For more information, see Escaping from HTML.
Note: Support for ASP-style tags was added in 3.0.4.
- auto_append_file string
Specifies the name of a file that is automatically parsed after the main file. The file is included as if it was called with the include() function, so include_path is used.
The special value none disables auto-appending.
Note: If the script is terminated with exit(), auto-append will not occur.
- auto_prepend_file string
Specifies the name of a file that is automatically parsed before the main file. The file is included as if it was called with the include() function, so include_path is used.
The special value none disables auto-prepending.
- cgi_ext string
- display_errors boolean
This determines whether errors should be printed to the screen as part of the HTML output or not.
- doc_root string
PHP's "root directory" on the server. Only used if non-empty. If PHP is configured with safe mode, no files outside this directory are served.
- engine boolean
This directive is really only useful in the Apache module version of PHP. It is used by sites that would like to turn PHP parsing on and off on a per-directory or per-virtual server basis. By putting engine off in the appropriate places in the httpd.conf file, PHP can be enabled or disabled.
- error_log string
Name of file where script errors should be logged. If the special value syslog is used, the errors are sent to the system logger instead. On UNIX, this means syslog(3) and on Windows NT it means the event log. The system logger is not supported on Windows 95.
- error_reporting integer
Set the error reporting level. The parameter is an integer representing a bit field. Add the values of the error reporting levels you want.
The default value for this directive is 7 (normal errors, normal warnings and parser errors are shown).
Table 3-1. Error Reporting Levels
|bit value||enabled reporting|
|8||non-critical style-related warnings|
- open_basedir string
Limit the files that can be opened by PHP to the specified directory-tree.
When a script tries to open a file with, for example, fopen or gzopen, the location of the file is checked. When the file is outside the specified directory-tree, PHP will refuse to open it. All symbolic links are resolved, so it's not possible to avoid this restriction with a symlink.
The special value . indicates that the directory in which the script is stored will be used as base-directory.
Under Windows, separate the directories with a semicolon. On all other systems, separate the directories with a colon. As an Apache module, open_basedir paths from parent directories are now automatically inherited.
Note: Support for multiple directories was added in 3.0.7.
The default is to allow all files to be opened.
- gpc_order string
Set the order of GET/POST/COOKIE variable parsing. The default setting of this directive is "GPC". Setting this to "GP", for example, will cause PHP to completely ignore cookies and to overwrite any GET method variables with POST-method variables of the same name.
- ignore_user_abort string
On by default. If changed to Off scripts will be terminated as soon as they try to output something after a client has aborted their connection. ignore_user_abort().
- include_path string
Specifies a list of directories where the require(), include() and fopen_with_path() functions look for files. The format is like the system's PATH environment variable: a list of directories separated with a colon in UNIX or semicolon in Windows.
Example 3-1. UNIX include_path
The default value for this directive is . (only the current directory).
Example 3-2. Windows include_path
- isapi_ext string
- log_errors boolean
Tells whether script error messages should be logged to the server's error log. This option is thus server-specific.
- magic_quotes_gpc boolean
Sets the magic_quotes state for GPC (Get/Post/Cookie) operations. When magic_quotes are on, all ' (single-quote), " (double quote), \ (backslash) and NUL's are escaped with a backslash automatically. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.
- magic_quotes_runtime boolean
If magic_quotes_runtime is enabled, most functions that return data from any sort of external source including databases and text files will have quotes escaped with a backslash. If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash.
- magic_quotes_sybase boolean
If magic_quotes_sybase is also on, a single-quote is escaped with a single-quote instead of a backslash if magic_quotes_gpc or magic_quotes_runtime is enabled.
- max_execution_time integer
This sets the maximum time in seconds a script is allowed to take before it is terminated by the parser. This helps prevent poorly written scripts from tying up the server. The default setting is 30.
- memory_limit integer
This sets the maximum amount of memory in bytes that a script is allowed to allocate. This helps prevent poorly written scripts for eating up all available memory on a server.
- nsapi_ext string
- register_globals boolean
Tells whether or not to register the EGPCS (Environment, GET, POST, Cookie, Server) variables as global variables. You may want to turn this off if you don't want to clutter your scripts' global scope with user data. This makes the most sense when coupled with track_vars - in which case you can access all of the EGPCS variables through the $HTTP_ENV_VARS, $HTTP_GET_VARS, $HTTP_POST_VARS, $HTTP_COOKIE_VARS, and $HTTP_SERVER_VARS arrays in the global scope.
- short_open_tag boolean
Tells whether the short form (<? ?>of PHP's open tag should be allowed. If you want to use PHP in combination with XML, you have to disable this option. If disabled, you must use the long form of the open tag (<?php ?>).
- sql.safe_mode boolean
- track_errors boolean
If enabled, the last error message will always be present in the global variable $php_errormsg.
- track_vars boolean
If enabled, then Environment, GET, POST, Cookie, and Server variables can be found in the global associative arrays $HTTP_ENV_VARS, $HTTP_GET_VARS, $HTTP_POST_VARS, $HTTP_COOKIE_VARS, and $HTTP_SERVER_VARS.
Note that as of PHP 4.0.3, track_vars is always turned on.
- upload_tmp_dir string
The temporary directory used for storing files when doing file upload. Must be writable by whatever user PHP is running as.
- user_dir string
The base name of the directory used on a user's home directory for PHP files, for example public_html.
- warn_plus_overloading boolean
If enabled, this option makes PHP output a warning when the plus (+) operator is used on strings. This is to make it easier to find scripts that need to be rewritten to using the string concatenator instead (.).
- SMTP string
DNS name or IP address of the SMTP server PHP under Windows should use for mail sent with the mail() function.
- sendmail_from string
Which "From:" mail address should be used in mail sent from PHP under Windows.
- sendmail_path string
Where the sendmail program can be found, usually /usr/sbin/sendmail or /usr/lib/sendmail configure does an honest attempt of locating this one for you and set a default, but if it fails, you can set it here.
Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail.
- enable_dl boolean
This directive is really only useful in the Apache module version of PHP. You can turn dynamic loading of PHP extensions with dl() on and off per virtual server or per directory.
The main reason for turning dynamic loading off is security. With dynamic loading, it's possible to ignore all the safe_mode and open_basedir restrictions.
The default is to allow dynamic loading, except when using safe-mode. In safe-mode, it's always imposible to use dl().
- extension_dir string
In what directory PHP should look for dynamically loadable extensions.
- extension string
Which dynamically loadable extensions to load when PHP starts up.
- sesam_oml string
Name of BS2000 PLAM library containing the loadable SESAM driver modules. Required for using SESAM functions. The BS2000 PLAM library must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.
- sesam_configfile string
Name of SESAM application configuration file. Required for using SESAM functions. The BS2000 file must be readable by the apache server's user id.
The application configuration file will usually contain a configuration like (see SESAM reference manual):
- sesam_messagecatalog string
Name of SESAM message catalog file. In most cases, this directive is not neccessary. Only if the SESAM message file is not installed in the system's BS2000 message file table, it can be set with this directive.
The message catalog must be set ACCESS=READ,SHARE=YES because it must be readable by the apache server's user id.
- sybct.allow_persistent boolean
Whether to allow persistent Sybase-CT connections. The default is on.
- sybct.max_persistent integer
The maximum number of persistent Sybase-CT connections per process. The default is -1 meaning unlimited.
- sybct.max_links integer
The maximum number of Sybase-CT connections per process, including persistent connections. The default is -1 meaning unlimited.
- sybct.min_server_severity integer
Server messages with severity greater than or equal to sybct.min_server_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_server_severity(). The default is 10 which reports errors of information severity or greater.
- sybct.min_client_severity integer
Client library messages with severity greater than or equal to sybct.min_client_severity will be reported as warnings. This value can also be set from a script by calling sybase_min_client_severity(). The default is 10 which effectively disables reporting.
- sybct.login_timeout integer
The maximum time in seconds to wait for a connection attempt to succeed before returning failure. Note that if max_execution_time has been exceeded when a connection attempt times out, your script will be terminated before it can take action on failure. The default is one minute.
- sybct.timeout integer
The maximum time in seconds to wait for a select_db or query operation to succeed before returning failure. Note that if max_execution_time has been exceeded when am operation times out, your script will be terminated before it can take action on failure. The default is no limit.
- sybct.hostname string
The name of the host you claim to be connecting from, for display by sp_who. The default is none.