Server Side Programming Articles - Page 2359 of 2650

The filter_list() function is used to list all supported filters.Syntaxfilter_list()ReturnThe filter_list() function returns an array of filters available. It returns an empty array if there are no filters.Example Live DemoOutputThe following is the output.int257 boolean258 float259 validate_regexp272 validate_domain277 validate_url273 validate_email274 validate_ip275 validate_mac276 string513 stripped513 encoded514 special_chars515 full_special_chars522 unsafe_raw516 email517 url518 number_int519 number_float520 magic_quotes521 callback1024

The filter_input_array() function gets names of external variables and filters them optionally. Syntax filter_input_array(type, arraydefine, add_empty) Parameters type − There are five types of inputs to check i.e. INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV. arraydefine − It specifies an array of filter arguments. It is optional. add_empty − If value is True, it adds missing keys as NULL to the return value. Return The filter_input_array() function returns an array containing the values of the variables on success, or false on failure. Example The following is an example that use the filter_input_array() function to filter POST ... Read More

The filter_input() function gets a name of external variable and filters it optionally.Syntaxfilter_input(type, var, filtername, options)Parameterstype − There are five types of inputs to check i.e. INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.var − The name of variable.filtername − The name of filter to get ID.options − Specifies options to use.ReturnThe filter_input() function returns the value of the variable on success, false on failure, or null if the parameter of variable is not set.Example Live Demo

The filter_id() function returns the filter ID of provided filter name.Syntaxfilter_id(filtername)Parametersfiltername − The name of filter to get the ID from.ReturnThe filter_id() function returns filter ID on success or FALSE, if the filter does not exist.ExampleOutputThe following is the output.int = 257 boolean = 258 float = 259 validate_regexp = 272 validate_domain = 277 validate_url = 273 validate_email = 274 validate_ip = 275 validate_mac = 276 string = 513 stripped = 513 encoded = 514 special_chars = 515 full_special_chars = 522 unsafe_raw = 516 email = 517 url = 518number_int = 519 number_float = 520 magic_quotes = 521 callback = 1024

The filter_has_var() function is used to check that variable of specified type exists or not.Syntaxfilter_has_var(type, var)Parameterstype − There are five types of inputs to check i.e. INPUT_GET, INPUT_POST, INPUT_COOKIE, INPUT_SERVER, or INPUT_ENV.var − The name of variable.ReturnThe filter_has_var() function returns true on success and false on failure.ExampleThe following is an example that is a quick check for the input variable "email”. The value INPUT_GET is used for this. Live Demo

The die() function can be used to stop the script and can be used to display a message to the end user. It can be used at the right side of the OR ( || ) operator and at left side can be any expression like the eval() function. Case 1 − Using die() function with no parameter The following is the output. Now we can use $! to print the error number and a message to the user in the die() function. Case 2 − Use of $! in the die() function The following is the ... Read More

Like other languages, Python also has some reserved words. These words hold some special meaning. Sometimes it may be a command, or a parameter etc. We cannot use keywords as variable names. The Python Keywords are True False class def return if elif else try except raise finally for in is not from import global lambda nonlocal pass while break continue and with as yield del or assert None The True & False Keywords The True and False are the truth ... Read More

Python can handle the precision of floating point numbers using different functions. Most functions for precision handling are defined in the math module. So to use them, at first we have to import the math module, into the current namespace. import math Now we will see some of the functions for precision handling. The trunc() function The trunc() method is used to remove all fractional part from a floating point number. So it returns only the integer part from the number. The ceil() function The ceil() method is used to return the Ceiling value of a ... Read More

In this section, we will see how to print formatted texts in Linux terminal. By formatting, we can change the text color, style, and some special features. Linux terminal supports some ANSI escape sequences to control the formatting, color and other features. So we have to embed some bytes with the text. So when the terminal is trying to interpret them, those formatting will be effective. The general syntax of ANSI escape sequence is like below − \x1b[A;B;C A is the Text Formatting Style B is the Text Color or Foreground Color C is the Background ... Read More

Like other languages, Python provides some inbuilt functions for reading, writing, or accessing files. Python can handle mainly two types of files. The normal text file and the binary files. For the text files, each lines are terminated with a special character '' (It is known as EOL or End Of Line). For the Binary file, there is no line ending character. It saves the data after converting the content into bit stream. In this section we will discuss about the text files. File Accessing Modes Sr.No Modes & Description 1 r It is Read ... Read More