[PHP] Practical functions 10_PHP tutorial

//Convert the characters of the IP dotted address back to the IP v4 format address

int ip2long(string ip_address)
//Convert the IP v4 format address back to the string of the IP dotted address

string long2ip(int proper_address)
//Get the environment variable varname. If successful, the variable value will be returned. If it fails, false will be returned.

string getenv(string varname)
//Used to set Set the system environment

void putenv(string setting)
//Get the owner name of the current PHP script

string get_current_user(void)
//Call the user function specified by function_name

string get_cfg_var(string function_name[,mixed parrameter[,mixed...]])
//Return the port (protocol) associated with service, which must be TCP or UDP

int getservbyname(string service,string protocol)
//Returns the service name (protocol) associated with port, which must be TCP or UDP

string getservbyport(int port,string protocol)
// Take the absolute value

mixed abs(mixed number)
//Square root

float sqrt(float arg)
//The power of the natural logarithm e

float exp(float arg)
//Return pi

double pi(void)
//Round

double round(double val)
// Calculate the smallest integer greater than the specified number

int ceil(float number)
//Calculate the largest integer less than the specified number

int floor(float number)
//Get the maximum value

mixed max(mixed arg1,mixed arg2...mixed argn)
//Take the minimum value

mixed min(mixed arg1,mixed arg2...mixed argn)
//Get random numbers

int rand([int min],[int max])
//Number system conversion

string base_convert(string number,int frombase,int tobase )
//Format number string

string number_format(float number,int[decimals],string[decpoint],string[thounsands_sep])