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Added files:
/phpdoc/en/appendices predefined.xml
Log:
Incremental update for list of predefined variables and constants. Please don't
link or translate, just copied over the information from the chapter sections.
Index: phpdoc/en/appendices/predefined.xml
+++ phpdoc/en/appendices/predefined.xml
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.1 $ -->
<-- Note: Please do not link or translate this file yet.
This is only an initial update, quite a few more commits will
follow for this appendix. -->
<appendix id="predefined">
<title>List of Predefined Variables and Constants</title>
<para>
The following is a listing of predefined variables and
and constants. These lists are neither exhaustive or complete.
</para>
<sect1 id="predefined.variables">
<title>Listing of Predefined Variables</title>
<sect2 id="predefined.variables.apache">
<title>Apache variables</title>
<simpara>
These variables are created by the <ulink
url="&url.apache;">Apache</ulink> webserver. If you are running
another webserver, there is no guarantee that it will provide the
same variables; it may omit some, or provide others not listed
here. That said, a large number of these variables are accounted
for in the <ulink url="&url.cgispec;">CGI 1.1
specification</ulink>, so you should be able to expect those.
</simpara>
<simpara>
Note that few, if any, of these will be available (or indeed have
any meaning) if running PHP on the command line.
</simpara>
<para>
<variablelist>
<varlistentry>
<term>$GATEWAY_INTERFACE</term>
<listitem>
<simpara>
What revision of the CGI specification the server is using;
i.e. 'CGI/1.1'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_NAME</term>
<listitem>
<simpara>
The name of the server host under which the current script is
executing. If the script is running on a virtual host, this
will be the value defined for that virtual host.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_SOFTWARE</term>
<listitem>
<simpara>
Server identification string, given in the headers when
responding to requests.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_PROTOCOL</term>
<listitem>
<simpara>
Name and revision of the information protocol via which the
page was requested; i.e. 'HTTP/1.0';
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$REQUEST_METHOD</term>
<listitem>
<simpara>
Which request method was used to access the page; i.e. 'GET',
'HEAD', 'POST', 'PUT'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$QUERY_STRING</term>
<listitem>
<simpara>
The query string, if any, via which the page was accessed.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$DOCUMENT_ROOT</term>
<listitem>
<simpara>
The document root directory under which the current script is
executing, as defined in the server's configuration file.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_ACCEPT</term>
<listitem>
<simpara>
Contents of the <literal>Accept:</literal> header from the
current request, if there is one.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_ACCEPT_CHARSET</term>
<listitem>
<simpara>
Contents of the <literal>Accept-Charset:</literal> header
from the current request, if there is one. Example:
'iso-8859-1,*,utf-8'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_ACCEPT_ENCODING</term>
<listitem>
<simpara>
Contents of the <literal>Accept-Encoding:</literal> header
from the current request, if there is one. Example: 'gzip'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_ACCEPT_LANGUAGE</term>
<listitem>
<simpara>
Contents of the <literal>Accept-Language:</literal> header
from the current request, if there is one. Example: 'en'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_CONNECTION</term>
<listitem>
<simpara>
Contents of the <literal>Connection:</literal> header from
the current request, if there is one. Example: 'Keep-Alive'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_HOST</term>
<listitem>
<simpara>
Contents of the <literal>Host:</literal> header from the
current request, if there is one.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_REFERER</term>
<listitem>
<simpara>
The address of the page (if any) which referred the browser
to the current page. This is set by the user's browser; not
all browsers will set this.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_USER_AGENT</term>
<listitem>
<simpara>
Contents of the <literal>User_Agent:</literal> header from
the current request, if there is one. This is a string
denoting the browser software being used to view the current
page; i.e. <computeroutput>Mozilla/4.5 [en] (X11; U; Linux
2.2.9 i586)</computeroutput>. Among other things, you can use
this value with <function>get_browser</function> to tailor
your page's functionality to the capabilities of the user's
browser.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$REMOTE_ADDR</term>
<listitem>
<simpara>
The IP address from which the user is viewing the current
page.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$REMOTE_PORT</term>
<listitem>
<simpara>
The port being used on the user's machine to communicate with
the web server.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SCRIPT_FILENAME</term>
<listitem>
<simpara>
The absolute pathname of the currently executing script.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_ADMIN</term>
<listitem>
<simpara>
The value given to the SERVER_ADMIN (for Apache) directive in
the web server configuration file. If the script is running
on a virtual host, this will be the value defined for that
virtual host.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_PORT</term>
<listitem>
<simpara>
The port on the server machine being used by the web server
for communication. For default setups, this will be '80';
using SSL, for instance, will change this to whatever your
defined secure HTTP port is.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SERVER_SIGNATURE</term>
<listitem>
<simpara>
String containing the server version and virtual host name
which are added to server-generated pages, if enabled.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$PATH_TRANSLATED</term>
<listitem>
<simpara>
Filesystem- (not document root-) based path to the current
script, after the server has done any virtual-to-real
mapping.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$SCRIPT_NAME</term>
<listitem>
<simpara>
Contains the current script's path. This is useful for pages
which need to point to themselves.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$REQUEST_URI</term>
<listitem>
<simpara>
The URI which was given in order to access this page; for
instance, '/index.html'.
</simpara>
</listitem>
</varlistentry>
</variablelist>
</para>
</sect2>
<sect2 id="predefined.variables.environment">
<title>Environment variables</title>
<simpara>
These variables are imported into PHP's global namespace from the
environment under which the PHP parser is running. Many are
provided by the shell under which PHP is running and different
systems are likely running different kinds of shells, a
definitive list is impossible. Please see your shell's
documentation for a list of defined environment variables.
</simpara>
<simpara>
Other environment variables include the CGI variables, placed
there regardless of whether PHP is running as a server module or
CGI processor.
</simpara>
</sect2>
<sect2 id="predefined.variables.php">
<title>PHP variables</title>
<simpara>
These variables are created by PHP itself. The
<varname>$HTTP_*_VARS</varname> variables are available only if
the <link linkend="ini.track-vars">track_vars</link>
configuration is turned on. When enabled, the variables are
always set, even if they are empty arrays. This prevents
a malicious user from spoofing these variables.
</simpara>
<note>
<para>
As of PHP 4.0.3, <link
linkend="ini.track-vars">track_vars</link> is always turned on,
regardless of the configuration file setting.
</para>
</note>
<para>
If the <link
linkend="ini.register-globals">register_globals</link> directive
is set, then these variables will also be made available in the
global scope of the script; i.e., separate from the
<varname>$HTTP_*_VARS</varname> arrays. This feature should be
used with care, and turned off if possible; while the
<varname>$HTTP_*_VARS</varname> variables are safe, the bare
global equivalents can be overwritten by user input, with
possibly malicious intent. If you cannot turn off <link
linkend="ini.register-globals">register_globals</link>, you must
take whatever steps are necessary to ensure that the data you are
using is safe.
</para>
<para>
<variablelist>
<varlistentry>
<term>$argv</term>
<listitem>
<simpara>
Array of arguments passed to the script. When the script is
run on the command line, this gives C-style access to the
command line parameters. When called via the GET method, this
will contain the query string.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$argc</term>
<listitem>
<simpara>
Contains the number of command line parameters passed to the
script (if run on the command line).
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$PHP_SELF</term>
<listitem>
<simpara>
The filename of the currently executing script, relative to
the document root. If PHP is running as a command-line
processor, this variable is not available.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_COOKIE_VARS</term>
<listitem>
<simpara>
An associative array of variables passed to the current
script via HTTP cookies.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_GET_VARS</term>
<listitem>
<simpara>
An associative array of variables passed to the current
script via the HTTP GET method.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_POST_VARS</term>
<listitem>
<simpara>
An associative array of variables passed to the current
script via the HTTP POST method.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_POST_FILES</term>
<listitem>
<simpara>
An associative array of variables containing information
about files uploaded via the HTTP POST method. See <link
linkend="features.file-upload.post-method">POST method
uploads</link> for information on the contents of
<varname>$HTTP_POST_FILES</varname>.
</simpara>
<para>
<varname>$HTTP_POST_FILES</varname> is available only in PHP
4.0.0 and later.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_ENV_VARS</term>
<listitem>
<simpara>
An associative array of variables passed to the current
script via the parent environment.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>$HTTP_SERVER_VARS</term>
<listitem>
<simpara>
An associative array of variables passed to the current
script from the HTTP server. These variables are analogous to
the Apache variables described above.
</simpara>
</listitem>
</varlistentry>
</variablelist>
</para>
</sect2>
</sect1>
<sect1 id="predefined.constants">
<title>Listing of Predefined Constants</title>
<para>
The predefined constants (always available) are:
<variablelist>
<varlistentry>
<term>__FILE__ (case-insensitive)</term>
<listitem>
<simpara>
The name of the script file presently being parsed. If used
within a file which has been included or required, then the
name of the included file is given, and not the name of the
parent file.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>__LINE__ (case-insensitive)</term>
<listitem>
<simpara>
The number of the line within the current script file which is
being parsed. If used within a file which has been included or
required, then the position within the included file is given.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>PHP_VERSION</term>
<listitem>
<simpara>
The string representation of the version of the PHP parser
presently in use; for example '4.1.0'.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>PHP_OS</term>
<listitem>
<simpara>
The name of the operating system on which the PHP parser is
executing;. Possible values may be :
"AIX", "Darwin" (MacOS), "Linux", "SunOS", "WIN32", "WINNT".
Note: other values may be available too.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>&true; (case-insensitive)</term>
<listitem>
<simpara>
A &true; value (see the <type>boolean</type> type).
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>&false; (case-insensitive)</term>
<listitem>
<simpara>
A &false; value (see the <type>boolean</type> type).
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>&null; (case-insensitive)</term>
<listitem>
<simpara>
A &null; value (see the <type>null</type> type).
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>E_ERROR</term>
<listitem>
<simpara>
Denotes an error other than a parsing error from which
recovery is not possible.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>E_WARNING</term>
<listitem>
<simpara>
Denotes a condition where PHP knows something is wrong, but
will continue anyway; these can be caught by the script
itself. An example would be an invalid regexp in
<function>ereg</function>.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>E_PARSE</term>
<listitem>
<simpara>
The parser choked on invalid syntax in the script
file. Recovery is not possible.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>E_NOTICE</term>
<listitem>
<simpara>
Something happened which may or may not be an error. Execution
continues. Examples include using an unquoted string as an array
index, or accessing a variable which has not been set.
</simpara>
</listitem>
</varlistentry>
<varlistentry>
<term>E_ALL</term>
<listitem>
<simpara>
All of the E_* constants rolled into one. If used with
<function>error_reporting</function>, will cause any and all
problems noticed by PHP to be reported.
</simpara>
</listitem>
</varlistentry>
</variablelist>
</para>
</sect1>
</appendix>
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