Common Environment system variables in php

PHP environment variables include $ GLOBALS [], $ _ SERVER [], $ _ GET [], $ _ POST [], $ _ COOKIE [], $ _ FILES [], $ _ ENV [], $ _ REQUEST [], and $ _ SESSION []. $ _ GET and $ _ POST are mainly for the data submitted by FORM forms, and $ _ COOKIE and $ _ SESSION are mainly for the client browser.

In any development language, some variables are called system variables or environment variables. For more information, see.

PHP environment variables include $ GLOBALS [], $ _ SERVER [], $ _ GET [], $ _ POST [], $ _ COOKIE [], $ _ FILES [], $ _ ENV [], $ _ REQUEST [], and $ _ SESSION []. $ _ GET and $ _ POST are mainly for data submitted by FORM forms. $ _ COOKIE and $ _ SESSION are mainly for client browser and server SESSION data. $ _ FILES mainly targets the data submitted during File upload. $ _ REQUEST mainly targets all REQUEST arrays in the submission form, including all content in $ _ GET, $ _ POST, and $ _ COOKIE, you can use the print_r function to output $ _ REQUEST or $ _ COOKIE for comparison.

$ _ SERVER variable

Is a global PHP environment variable that contains server-side information. $ HTTP_SERVER_VARS is used in versions earlier than PHP4.1.0.

$ _ SERVER ['php _ SELF ']

# The file name of the script being executed, which is related to document root. In FORM, if the execution file is itself, you can use

$ _ SERVER ['query _ string']

# Obtain the query statement, that is, get '? 'Value after

$ _ SERVER ['document _ root']

# The document root directory where the script is currently running. Defined in the server configuration file.

$ _ SERVER ['http _ ACCEPT ']

# Accept of the current request: content in the header.

$ _ SERVER ['http _ accept_charset']

# Accept-Charset of the current request: content in the header. Example: "ISO-8859-1, *, UTF-8 ".

$ _ SERVER ['http _ ACCEPT_ENCODING ']

# Accept-Encoding of the current request: content in the header. For example, "gzip ".

$ _ SERVER ['http _ ACCEPT_LANGUAGE ']

# Accept-Language of the current request: content in the header. For example, "en ".

$ _ SERVER ['http _ connection']

# Connection of the current request: content in the header. For example, "Keep-Alive ".

$ _ SERVER ['http _ host']

# Host of the current request: content in the header.

$ _ SERVER ['http _ referer']

# URL of the previous page linked to the current page.

$ _ SERVER ['http _ USER_AGENT ']

# User_Agent of the current request: content in the header.

$ _ SERVER ['server _ name']

# Name of the server host where the currently running PHP program is located.

$ _ SERVER ['request _ method']

# The request method used to access the page, namely GET, HEAD, POST, and PUT.

$ _ SERVER ['document _ root']

# The document root directory of the currently running PHP program. That is, the definition in the PHP. ini file.

$ _ SERVER ['http _ referer']

# URL of the previous page linked to the current page. This function is useful in page navigation.

$ _ SERVER ['remote _ ADDR ']

# Browsing the IP address of the visitor on the current page.

$ _ SERVER ['remote _ host']

# The host name of the user browsing the current page.

$ _ SERVER ['remote _ port']

# The port used by the user who is visiting to connect to the server.

$ _ SERVER ['script _ filename']

# The absolute path name of the currently executed script.

$ _ SERVER ['server _ port']

# The port used by the server

$ _ SERVER ['script _ name']

# Contains the path of the current script. This is useful when the page needs to point to itself.

$ _ SERVER ['request _ URI ']

# The URI required to access this page. For example, "/index.html ".

$ _ SERVER ['php _ AUTH_USER ']

# In the HTTP user logon authentication function, this variable is the user name entered by the user.

$ _ SERVER ['php _ AUTH_PW ']

# In the HTTP user logon authentication function, this variable is the password entered by the user.

$ _ SERVER ['auth _ type']

# In the HTTP user logon authentication function, this variable is the authentication type.

$ _ SERVER ['server _ soft']

# The string identified by the server, which is provided in the header of the response request.

System constant

_ FILE _ absolute path and FILE name of the current PHP script

_ LINE _ stores the row number of the constant

_ FUNCTION _ name of the FUNCTION where the constant is stored

_ CLASS _ stores the name of the CLASS where the constant is located.

PHP_VERSION stores the current PHP version, which can also be obtained through the PHPVERSION () function.

PHP_ OS stores the operating system of the current server