PHP options and related information function library

error_log: Send an error message.
error_reporting: Configure the level of error information reporting.
getenv: Get the system environment variable
get_cfg_var: Get the configuration option value of PHP.
get_current_user: Get the owner name of the PHP trip.
get_magic_quotes_gpc: Get the value of PHP environment variable magic_quotes_gpc.
get_magic_quotes_runtime: Get the value of PHP environment variable magic_quotes_runtime.
getlastmod: Returns the last modification time of the web page.
getmyinode: Returns the inode value of the web page.
getmypid: Returns the trip code of PHP.
getmyuid: Returns the user code of PHP.
getrusage: Returns the system resource usage.
phpinfo: Returns all relevant information about PHP.
phpversion : Returns PHP version information.
putenv: Configure system environment variables.
set_magic_quotes_runtime: Configure magic_quotes_runtime value.
set_time_limit: Configure the longest execution time of this page.

int error_log
Syntax: int error_log(string message, int message_type, string [destination], string [extra_headers]);
Return value: integer
Function type: PHP system function
Content description: This function will send error information to the error log file of the Web server, TCP Port, or to the specified file. The first parameter message is the error message to be sent. The second parameter message_type is an integer value: 0 means sending the log to the operating system (UNIX records events in syslog and Windows NT); 1 uses PHP's Mail() function to send the information to an E-Mail. The four parameters extra_headers will also be used; 2 will send the error message to the TCP port, and the third parameter destination represents the destination IP and Port; 3 will save the information in the file destination.
Usage Example
This example is to deal with problems when logging into the Oracle database.
if (!Ora_Logon($username, $password)) {
error_log("Oracle database is unavailable!", 0);
}
if (!( $foo = allocate_new_foo()) {
error_log("It’s annoying!", 1, "webmaster@www.mydomain.com.tw");
}
error_log("Screwed up! ", 2, "127.0.0.1:7000");
error_log("Screwed up!", 2, "loghost");
error_log("Screwed up!", 3, "/var/ tmp/my-errors.log");
?>

error_reporting
Configure the level of error message reporting.
Syntax: int error_reporting(int [level]);
Return value: Integer
Function type: PHP system function
Content description: This function is used to configure the level of error message reporting. The parameter level is an integer bit mask (bitmask), see the table below
Mask The mask value represents the name
1 E_ERROR
2 E_WARNING
4 E_PARSE
8 E_NOTICE
16 E_CORE_ERROR
32 E_CORE_WARNING

E_N OTICE means general situation Not logged, only used when there is an error in the program, such as trying to access a variable that does not exist, or calling the stat() function to view a file that does not exist.
E_WARNING will usually be displayed, but the program will not be interrupted. Execution. This is useful for debugging. For example, calling ereg() with a problematic regular expression will usually show up, meaning that the memory configuration cannot be traced using this mask. or other errors.
E_PARSE parses errors from the syntax.
E_CORE_ERROR is like E_ERROR, but does not include errors caused by PHP core.
E_CORE_WARNING is like E_WARNING, but does not include PHP core error warnings. >
getenv
Get the system environment variable
Syntax: string getenv(string varname);
Return value: String
Function type: PHP System function
Content description: If correct Get the environment variable varname and return the variable value. Returns false on failure.
Usage Example
The following example can obtain the URL of the machine where the user's browser is located
$ip = getenv("REMOTE_ADDR");
?>

get_cfg_var
Get the configuration option value of PHP.
Syntax: string get_cfg_var(string varname);
Return value: String
Function type: PHP system function
Content description: If the current PHP configuration option varname is obtained correctly, the variable value is returned. Returns false on failure.

get_current_user
Get the owner name of the PHP trip.
Syntax: string get_current_user(void);
Return value: String
Function type: PHP system function
Content description: This function is used to obtain the owner name of the PHP program process.
Reference: getmyuid() getmypid() getmyinode() getlastmod()

get_magic_quotes_gpc
Get the value of PHP environment variable magic_quotes_gpc.
Syntax: long get_magic_quotes_gpc(void);
Return value: long integer
Function type: PHP system function
Content description: This function obtains the PHP environment configuration variable magic_quotes_gpc (GPC, Get/Post/ Cookie) value. Returning 0 means turning off this function; returning 1 means turning this function on. When magic_quotes_gpc is turned on, all ' (single quotes), " (double quotes), (backslashes) and null characters will automatically be converted to overflow characters containing backslashes.
Reference: get_magic_quotes_runtime() set_magic_quotes_runtime()

get_magic_quotes_runtime
Get the value of PHP environment variable magic_quotes_runtime
Syntax: long get_magic_quotes_runtime(void);
Return value: long integer
Function type: PHP system function
Content. Description: This function obtains the value of the PHP environment configuration variable magic_quotes_runtime. Returning 0 indicates that this function is turned off; returning 1 indicates that this function is turned on. If magic_quotes_runtime is turned on, all externally imported database data or files will be automatically converted to contain backslashes. Information about overflow characters.
Reference: get_magic_quotes_gpc() set_magic_quotes_runtime()

getlastmod
Returns the last modification time of the web page.
Syntax: int getlastmod(void);
Return value. : Integer
Function type: PHP system function
Content description: This function returns the last modification time of the web page specified by this function. What is returned is the UNIX timestamp (timestamp) format, which can be used with the 4.7.2 date() function Format the return value. If the execution fails, return a false value. Example: The following return value is similar to 'This page was last modified: June 19 1999 20:43:59.'
< ?php
echo "The last modification time of this page: ".date("F d Y H:i:s.", getlastmod());
?>
Reference: date() getmyuid( ) get_current_user() getmyinode() getmypid()

getmyinode
Returns the inode value of the web page.
Syntax: int getmyinode(void);
Return value: Integer
Function type. : PHP system function
Content description: This function returns the inode value of the web page. If the execution fails, a false value is returned.
Reference: getmyuid() get_current_user() getmypid() getlastmod()

getmypid
Return the PHP trip code.
Syntax: int getmypid(void);
Return value: integer
Function type: PHP system function
Content description: This function returns the PHP trip code value (PID). If the execution fails, a false value is returned. When PHP exists as an Apache module, the PID value returned may not be correct.
Reference: getmyuid() get_current_user() getmyinode() getlastmod()

getmyuid
Return the user code of PHP.
Syntax: int getmyuid(void);
Return value: Integer
Function type: PHP system function
Content description: This function returns the user code (UID) of PHP. If the execution fails, a false value is returned.
Reference: getmypid() get_current_user() getmyinode() getlastmod()

getrusage
Returns the system resource usage.
Syntax: array getrusage(int [who]);
Return value: array
Function type: PHP system function
Content description: This function uses the UNIX system call getrusage(2). The returned information is returned in the form of an array. If the parameter who is 1, this function will call RUSAGE_CHILDREN. Further information can be found in the UNIX library documentation.
Usage example
$dat = getrusage();
echo $dat["ru_nswap"]; // Number of Swaps
echo $dat["ru_majflt"]; // Number of pages
echo $dat["ru_utime.tv_sec"]; // Usage time (seconds)
echo $dat["ru_utime.tv_usec"]; // Usage time (milliseconds)
?>

phpinfo
Returns all relevant information about PHP.
Syntax: int phpinfo(void);
Return value: integer
Function type: PHP system function
Content description: This function returns all information of PHP. Includes PHP compilation options and extended configurations, PHP version, server information and environment variables, PHP environment variables, operating system version information, path and environment variable configuration, HTTP headers, and copyright notices.
Reference: phpversion()

phpversion
Return PHP version information.
Syntax: string phpversion(void);
Return value: String
Function type: PHP system function
Content description: This function returns PHP version information.
Usage examples
The return value in the following example is similar to 'The PHP version used by this site is: 3.0.11'
echo "The PHP version used by this site is: ".phpversion();
?>
Reference: phpinfo()

putenv
Configure system environment variables.
Syntax: void putenv(string setting);
Return value: None
Function type: PHP system function
Content description: This function is used to configure system environment variables.
Usage Example
Configure the environment variable NLS_LANG required for Oracle database, and the returned data contains Chinese BIG5 code. putenv("NLS_LANG=american_taiwan.zht16big5");
?>
set_magic_quotes_runtime
Configure magic_quotes_runtime value.
Syntax: long set_magic_quotes_runtime(int new_setting);
Return value: long integer
Function type: PHP system function
Content description
This function is used to configure the magic_quotes_runtime value.
Reference: get_magic_quotes_gpc() get_magic_quotes_runtime()

set_time_limit
Configure the longest execution time of this page.
Syntax: void set_time_limit(int seconds);
Return value: None
Function type: PHP system function
Content description: This function is used to configure the longest execution time of the page. The default value is 30 seconds, which is configured in the max_execution_time variable in php.ini. If it is configured as 0, the maximum time is not limited. The calculation starts when this function is executed. For example, if the default is 30 seconds, and 25 seconds have been executed before this function is executed, and this function is used to change it to 20 seconds, the maximum execution time of the page will be 45 seconds.

PHP options and related information function library_PHP tutorial