Copied verbatim from The GNU C Library Manual . When you have finished using a socket, you can simply close its file descriptor with close ; see Opening and Closing Files . If there is still data waiting to be transmitted over the connection, normally close tries to complete this transmission. You can control this behavior using the SO_LINGER socket option to specify a timeout period; see Socket Options . You can also shut down only reception or transmission on a connection by calling shutdown , which is declared in sys/socket.h . Function: int shutdown (int socket, int how) The shutdown function shuts down the connection of socket socket. The argument how specifies what action to perform: 0 - Stop receiving data for this socket....

The longjmp function jumps to the line where setjmp was last called. In return, setjmp returns the value passed in as the second parameter to longjmp . #include <stdio.h> #include <stdlib.h> #incl... Result: $ ./longjmp val is 0 val is 1 --> val is ...

There are two sides to an IP socket: the local side and the remote side: The getpeername function retrieves the peer address of the specified socket. #include <sys/socket.h> int getpeername(int soc... Example: struct sockaddr_in addr; socklen_t socklen = si... The getsockname function retrieves the locally-bound name of the specified socket. #include <sys/socket.h> int getsockname(int soc... Example: struct sockaddr_in addr; socklen_t socklen = si...

A pair of C functions convert between an Internet address and a string (ASCII): #include <arpa/inet.h> /* * Returns a poin... However , these functions do not support IPv6. The new pair is: #include <arpa/inet.h> /* Convert a Internet ad... Examples: #include <sys/socket.h> #include <netinet/in.h>...

The PHP function strval returns the string value of a variable. It does the same thing as casting a variable to string, or automatic conversion where string is expected. Conversion rules: Type String Value Boolean TRUE '1' Boolean FALSE '' (empty string) integer of float string representing the number Array The string 'Array' Object Result of __toString() if defined, error otherwise Resource 'Resource id #n' , where n is a number assigned to the resource. NULL '' (empty string) Example: <?php set_error_handler(function($errno, $errst... Results: bool(true) --------------------- strval: '1'...

The PHP function ctype_digit returns true when all characters in a string is numeric. Use this function only on strings. You get unexpected results with other data types. Example: <?php $a = array("124.34", "00088760", "1.3e5",... Results: string(6) "124.34" ----------------- ctype_d...

List of functions testing variable type: Function Description is_bool Finds out whether a variable is a boolean is_double Alias of is_float() is_float Finds whether the type of a variable is float is_int Find whether the type of a variable is integer is_integer Alias of is_int() is_long Alias of is_int() is_null Finds whether a variable is NULL is_numeric Finds whether a variable is a number or a numeric string is_object Finds whether a variable is an object is_real Alias of is_float() is_scalar Finds whether a variable is a scalar is_string Find whether the type of a variable is string Test code: <?php class A { } $a = ar... Output: var_dump: int(1) ------------------------- i...

The PHP function array_unique removes duplicate values from arrays. It takes an optional parameter $sort_flags , which can be one of: SORT_REGULAR : compare items normally (don't change types) SORT_NUMERIC : compare items numerically SORT_STRING : compare items as strings SORT_LOCALE_STRING : compare items as strings, based on the current locale. Example: <?php $a = array( '1' => 'Apple', ... Output: array_unique results: array(3) { [1]=> ...

Python defines a long list of special methods to customize class behavior. This is a short list for the Basic Customizations . Method Description object.__new__(cls[, ...]) Called to create a new instance of class cls. __new__() is a static method (special-cased so you need not declare it as such) that takes the class of which an instance was requested as its first argument. __new__() is intended mainly to allow subclasses of immutable types (like int, str, or tuple) to customize instance creation. It is also commonly overridden in custom metaclasses in order to customize class creation. object.__init__(self[,...]) Called when the instance is created. The arguments are those passed to the class constructor expression. If a base class has an __init__() method, the derived class’s __init__()...

There are two functions: int strcasecmp (string $str1 , string $str2) : binary safe case-insensitive string comparison. int strnatcasecmp (string $str1 , string $str2) : case insensitive string comparisons using a "natural order" algorithm (a comparison algorithm that orders alphanumeric strings in the way a human being would). In both cases the function returns: < 0 if str1 is less than str2 = 0 if str1 is equal to str2 > 0 if str1 is greater than str2