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A.2b. Alphabetical Listing of PHP Functions (f-i)

fclose

bool fclose(int handle)

Closes the file referenced by handle; returns true if successful and false if not.

feof

int feof(int handle)

Returns true if the marker for the file referenced by handle is at the end of the file (EOF) or if an error occurs. If the marker is not at EOF, returns false.

fflush

int fflush(int handle)

Commits any changes to the file referenced by handle to disk, ensuring that the file contents are on disk and not just in a disk buffer. If the operation succeeds, the function returns true; otherwise it returns false.

fgetc

string fgetc(int handle)

Returns the character at the marker for the file referenced by handle and moves the marker to the next character. If the marker is at the end of the file, the function returns false.

fgetcsv

array fgetcsv(int handle, int length[, string delimiter])

Reads the next line from the file referenced by handle and parses the line as a comma-separated values (CSV) line. The longest line to read is given by length. If supplied, delimiter is used to delimit the values for the line instead of commas. For example, to read and display all lines from a file containing tab-separated values, use:

$fp = fopen("somefile.tab", "r");
 
while($line = fgetcsv($fp, 1024, "\t")) {
  print "<p>" . count($line) . "fields:</p>";
  print_r($line);
}

fclose($fp);
fgets

string fgets(int handle, int length)

Reads a string from the file referenced by handle; a string of no more than length characters is returned, but the read ends at length - 1 (for the end-of-line character) characters, at an end-of-line character, or at EOF. Returns false if any error occurs.

fgetss

string fgetss(int handle, int length[, string tags])

Reads a string from the file referenced by handle; a string of no more than length characters is returned, but the read ends at length-1 (for the end-of-line character) characters, at an end-of-line character, or at EOF. Any PHP and HTML tags in the string, except those listed in tags, are stripped before returning it. Returns false if any error occurs.

file

array file(string path[, int include])

Reads the file at path and returns an array of lines from the file. The strings include the end-of-line characters. If include is specified and is true, the include path is searched for the file.

file_exists

bool file_exists(string path)

Returns true if the file at path exists and false if not.

fileatime

int fileatime(string path)

Returns the last access time, as a Unix timestamp value, for the file path. Because of the cost involved in retrieving this information from the filesystem, this information is cached; you can clear the cache with clearstatcache( ).

filectime

int filectime(string path)

Returns the creation date, as a Unix timestamp value, for the file path. Because of the cost involved in retrieving this information from the filesystem, this information is cached; you can clear the cache with clearstatcache( ).

filegroup

int filegroup(string path)

Returns the group ID of the group owning the file path. Because of the cost involved in retrieving this information from the filesystem, this information is cached; you can clear the cache with clearstatcache( ).

fileinode

int fileinode(string path)

Returns the inode number of the file path, or false if an error occurs. This information is cached; see clearstatcache.

filemtime

int filemtime(string path)

Returns the last-modified time, as a Unix timestamp value, for the file path. This information is cached; you can clear the cache with clearstatcache( ).

fileowner

int fileowner(string path)

Returns the user ID of the owner of the file path, or false if an error occurs. This information is cached; you can clear the cache with clearstatcache( ).

fileperms

int fileperms(string path)

Returns the file permissions for the file path; returns false if any error occurs. This information is cached; you can clear the cache with clearstatcache( ).

filesize

int filesize(string path)

Returns the size, in bytes, of the file path. If the file does not exist, or any other error occurs, the function returns false. This information is cached; you can clear the cache with clearstatcache( ).

filetype

string filetype(string path)

Returns the type of file given in path. The possible types are:

 

fifo

 

The file is a fifo pipe.

 

char

 

The file is a text file.

 

dir

 

path is a directory.

 

block

 

A block reserved for use by the filesystem.

 

link

 

The file is a symbolic link.

 

file

 

The file contains binary data.

 

unknown

 

The file's type could not be determined.

flock

bool flock(int handle, int operation[, int would_block])

Attempts to lock the file path of the file specified by handle. The operation is one of the following values:

 

LOCK_SH

 

Shared lock (reader)

 

LOCK_EX

 

Exclusive lock (writer)

 

LOCK_UN

 

Release a lock (either shared or exclusive)

 

LOCK_NB

 

Add to LOCK_SH or LOCK_EX to obtain a non-blocking lock

If specified, would_block is set to true if the operation would cause a block on the file. The function returns false if the lock could not be obtained, and true if the operation succeeded.

Because file locking is implemented at the process level on most systems, flock( ) cannot prevent two PHP scripts running in the same web server process from accessing a file at the same time.

floor

double floor(double number)

Returns the largest integer value less than or equal to number.

flush

void flush( )

Sends the current output buffer to the client and empties the output buffer. See Chapter 13 for more information on using the output buffer.

fopen

int fopen(string path, string mode[, bool include])

Opens the file specified by path and returns a file resource handle to the open file. If path begins with http://, an HTTP connection is opened and a file pointer to the start of the response is returned. If path begins with ftp://, an FTP connection is opened and a file pointer to the start of the file is returned; the remote server must support passive FTP.

If path is php://stdin, php://stdout, or php://stderr, a file pointer to the appropriate stream is returned.

The parameter mode specifies the permissions to open the file with. It must be one of the following:

 

r

 

Open the file for reading; file pointer will be at beginning of file.

 

r+

 

Open the file for reading and writing; file pointer will be at beginning of file.

 

w

 

Open the file for writing. If the file exists, it will be truncated to zero length; if the file doesn't already exist, it will be created.

 

w+

 

Open the file for reading and writing. If the file exists, it will be truncated to zero length; if the file doesn't already exist, it will be created. The file pointer starts at the beginning of the file.

 

a

 

Open the file for writing. If the file exists, the file pointer will be at the end of the file; if the file does not exist, it is created.

 

a+

 

Open the file for reading and writing. If the file exists, the file pointer will be at the end of the file; if the file does not exist, it is created.

If include is specified and is true, fopen( ) tries to locate the file in the current include path.

If any error occurs while attempting to open the file, false is returned.

fpassthru

int fpassthru(int handle)

Outputs the file pointed to by handle and closes the file. The file is output from the current file pointer location to EOF. If any error occurs, false is returned; if the operation is successful, true is returned.

fputs

bool fputs(int handle, string string[, int length])

This function is an alias for fwrite( ).

fread

string fread(int handle, int length)

Reads length bytes from the file referenced by handle and returns them as a string. If fewer than length bytes are available before EOF is reached, the bytes up to EOF are returned.

fscanf

mixed fscanf(int handle, string format[, string name1[, ... string nameN]])

Reads data from the file referenced by handle and returns a value from it based on format. For more information on how to use this function, see sscanf.

If the optional name1 through nameN parameters are not given, the values scanned from the file are returned as an array; otherwise, they are put into the variables named by name1 through nameN.

fseek

int fseek(int handle, int offset[, int from])

Moves the file pointer in handle to the byte offset. If from is specified, it determines how to move the file pointer. from must be one of the following values:

 

SEEK_SET

 

Sets the file pointer to the byte offset (the default)

 

SEEK_CUR

 

Sets the file pointer to the current location plus offset bytes

 

SEEK_END

 

Sets the file pointer to EOF minus offset bytes

This function returns 0 if the function was successful and -1 if the operation failed.

fsockopen

int fsockopen(string host, int port[, int error[, string message[, double timeout]]])

Opens a TCP or UDP connection to a remote host on a specific port. By default, TCP is used; to connect via UDP, host must begin with the protocol udp://. If specified, timeout indicates the length of time in seconds to wait before timing out.

If the connection is successful, a virtual file pointer is returned, which can be used with functions such as fgets( ) and fputs( ). If the connection fails, false is returned. If error and message are supplied, they are set to the error number and error string, respectively.

fstat

array fstat(int handle)

Returns an associative array of information about the file referenced by handle. The following values(given here with their numeric and key indexes) are included in the array:

 

dev (0)

 

The device on which the file resides

 

ino (1)

 

The file's inode

 

mode (2)

 

The mode with which the file was opened

 

nlink (3)

 

The number of links to this file

 

uid (4)

 

The user ID of the file's owner

 

gid (5)

 

The group ID of the file's owner

 

rdev (6)

 

The device type (if the file is on an inode device)

 

size (7)

 

The file's size (in bytes)

 

atime (8)

 

The time of last access (in Unix timestamp format)

 

mtime (9)

 

The time of last modification (in Unix timestamp format)

 

ctime (10)

 

The time the file was created (in Unix timestamp format)

 

blksize (11)

 

The blocksize (in bytes) for the filesystem

 

blocks (12)

 

The number of blocks allocated to the file

ftell

int ftell(int handle)

Returns the byte offset to which the file referenced by handle is set. If an error occurs, returns false.

ftruncate

int ftruncate(int handle, int length)

Truncates the file referenced by handle to length bytes. Returns true if the operation is successful and false if not.

func_get_arg

mixed func_get_arg(int index)

Returns the index element in the function argument array. If called outside a function, or if index is greater than the number of arguments in the argument array, func_get_arg( ) generates a warning and returns false.

func_get_args

array func_get_args( )

Returns the array of arguments given to the function as an indexed array. If called outside a function, func_get_args( ) returns false and generates a warning.

func_num_args

int func_num_args( )

Returns the number of arguments passed to the current user-defined function. If called outside a function, func_num_args( ) returns false and generates a warning.

function_exists

bool function_exists(string function)

Returns true if a function with function has been defined, and false otherwise. The comparison to check for a matching function is case-insensitive.

fwrite

int fwrite(int handle, string string[, int length])

Writes string to the file referenced by handle. The file must be open with write privileges. If length is given, only that many bytes of the string will be written. Returns the number of bytes written, or -1 on error.

get_browser

string get_browser([string name])

Returns an object containing information about the user's current browser, as found in $HTTP_USER_AGENT, or the browser identified by the user agent name. The information is gleaned from the browscap.ini file. The version of the browser and various capabilities of the browser, such as whether or not the browser supports frames, cookies, and so on, are returned in the object.

get_cfg_var

string get_cfg_var(string name)

Returns the value of the PHP configuration variable name. If name does not exist, get_cfg_var( ) returns false. Only those configuration variables set in a configuration file, as returned by cfg_file_path( ), are returned by this function—compile-time settings and Apache configuration file variables are not returned.

get_class

string get_class(object object)

Returns the name of the class of which the given object is an instance. The class name is returned as a lowercase string.

get_class_methods

array get_class_methods(mixed class)

If the parameter is a string, returns an array containing the names of each method defined for the specified class. If the parameter is an object, this function returns the methods defined in the class of which the object is an instance.

get_class_vars

array get_class_vars(string class)

Returns an associative array of default properties for the given class. For each property, an element with a key of the property name and a value of the default value is added to the array. Properties that do not have default values are not returned in the array.

get_current_user

string get_current_user( )

Returns the name of the user under whose privileges the current PHP script is executing.

get_declared_classes

array get_declared_classes( )

Returns an array containing the name of each defined class. This includes any classes defined in extensions currently loaded in PHP.

get_defined_constants

array get_defined_constants( )

Returns an associative array of all constants defined by extensions and the define( ) function and their values.

get_defined_functions

array get_defined_functions( )

Returns an array containing the name of each defined function. The returned array is an associative array with two keys, internal and user. The value of the first key is an array containing the names of all internal PHP functions; the value of the second key is an array containing the names of all user-defined functions.

get_defined_vars

array get_defined_vars( )

Returns an array of all defined environment, server, and user-defined variables.

get_extension_funcs

array get_extension_funcs(string name)

Returns an array of functions provided by the extension specified by name.

get_html_translation_table

array get_html_translation_table([int which[, int style]])

Returns the translation table used by either htmlspecialchars( ) or htmlentities( ). If which is HTML_ENTITIES, the table used by htmlentities( ) is returned; if which is HTML_SPECIALCHARS, the table used by htmlspecialchars( ) is returned. Optionally, you can specify which quotes style you want returned; the possible values are the same as those in the translation functions:

 

ENT_COMPAT (default)

 

Converts double quotes, but not single quotes

 

ENT_NOQUOTES

 

Does not convert either double quotes or single quotes

 

ENT_QUOTES

 

Converts both single and double quotes

get_included_files

array get_included_files( )

Returns an array of the files included into the current script by include( ), include_once( ), require( ), and require_once( ).

get_loaded_extensions

array get_loaded_extensions( )

Returns an array containing the names of every extension compiled and loaded into PHP.

get_magic_quotes_gpc

bool get_magic_quotes_gpc( )

Returns the current value of the quotes state for GET/POST/cookie operations. If true, all single quotes (''), double quotes (""), backslashes (\), and NUL-bytes ("\0") are automatically escaped and unescaped as they go from the server to the client and back.

get_meta_tags

array get_meta_tags(string path[, int include])

Parses the file path and extracts any HTML meta tags it locates. Returns an associative array, the keys of which are name attributes for the meta tags, and the values of which are the appropriate values for the tags. The keys are in lowercase, regardless of the case of the original attributes. If include is specified and true, the function searches for path in the include path.

get_object_vars

array get_object_vars(object object)

Returns an associative array of the properties for the given object. For each property, an element with a key of the property name and a value of the current value is added to the array. Properties that do not have current values are not returned in the array, even if they are defined in the class.

get_parent_class

string get_parent_class(mixed object)

Returns the name of the parent class for the given object. If the object does not inherit from another class, returns an empty string.

get_required_files

array get_required_files( )

This function is an alias for get_included_files( ).

get_resource_type

string get_resource_type(resource handle)

Returns a string representing the type of the specified resource handle. If handle is not a valid resource, the function generates an error and returns false. The kinds of resources available are dependent on the extensions loaded, but include "file", "mysql link", and so on.

getcwd

string getcwd( )

Returns the path of the PHP process's current working directory.

getdate

array getdate([int timestamp])

Returns an associative array containing values for various components for the given timestamp time and date. If no timestamp is given, the current date and time is used. The array contains the following keys and values:

 

seconds

 

Seconds

 

minutes

 

Minutes

 

hours

 

Hours

 

mday

 

Day of the month

 

wday

 

Numeric day of the week (Sunday is "0")

 

mon

 

Month

 

year

 

Year

 

yday

 

Day of the year

 

weekday

 

Name of the day of the week ("Sunday" through "Saturday")

 

month

 

Name of the month ("January" through "December")

getenv

string getenv(string name)

Returns the value of the environment variable name. If name does not exist, getenv( ) returns false.

gethostbyaddr

string gethostbyaddr(string address)

Returns the hostname of the machine with the IP address address. If no such address can be found, or if address doesn't resolve to a hostname, address is returned.

gethostbyname

string gethostbyname(string host)

Returns the IP address for host. If no such host exists, host is returned.

gethostbynamel

array gethostbynamel(string host)

Returns an array of IP addresses for host. If no such host exists, returns false.

getlastmod

int getlastmod( )

Returns the Unix timestamp value for the last-modification date of the file containing the current script. If an error occurs while retrieving the information, returns false.

getmxrr

int getmxrr(string host, array hosts[, array weights])

Searches DNS for all Mail Exchanger (MX) records for host. The results are put into the array hosts. If given, the weights for each MX record are put into weights. Returns true if any records are found and false if none are found.

getmyinode

int getmyinode( )

Returns the inode value of the file containing the current script. If an error occurs, returns false.

getmypid

int getmypid( )

Returns the process ID for the PHP process executing the current script. When PHP runs as a server module, any number of scripts may share the same process ID, so it is not necessarily a unique number.

getprotobyname

int getprotobyname(string name)

Returns the protocol number associated with name in /etc/protocols.

getprotobynumber

string getprotobynumber(int protocol)

Returns the protocol name associated with protocol in /etc/protocols.

getrandmax

int getrandmax( )

Returns the largest value that can be returned by rand( ).

getrusage

array getrusage([int who])

Returns an associative array of information describing the resources being used by the process running the current script. If who is specified and is equal to 1, information about the process's children is returned. A list of the keys and descriptions of the values can be found under the getrusage(2) Unix command.

getservbyname

int getservbyname(string service, string protocol)

Returns the port associated with service in /etc/services. protocol must be either TCP or UDP.

getservbyport

string getservbyport(int port, string protocol)

Returns the service name associated with port and protocol in /etc/services. protocol must be either TCP or UDP.

gettimeofday

array gettimeofday( )

Returns an associative array containing information about the current time, as obtained through gettimeofday(2).

The array contains the following keys and values:

 

sec

 

The current number of seconds since the Unix epoch.

 

msec

 

The current number of microseconds to add to the number of seconds.

 

minuteswest

 

The number of minutes west of Greenwich the current time zone is.

 

dsttime

 

The type of Daylight Savings Time correction to apply (during the appropriate time of year, a positive number if the time zone observes Daylight Savings Time).

gettype

string gettype(mixed value)

Returns a string description of the type of value. The possible values for value are "boolean", "integer", "double", "string", "array", "object", "resource", "NULL", and "unknown type".

gmdate

string gmdate(string format[, int timestamp])

Returns a formatted string for a timestamp date and time. Identical to date( ), except that it always uses Greenwich Mean Time (GMT), rather than the time zone specified on the local machine.

gmmktime

int gmmktime(int hour, int minutes, int seconds, int month, int day, int year)

Returns a timestamp date and time value from the provided set of values. Identical to mktime( ), except that the values represent a GMT time and date, rather than one in the local time zone.

gmstrftime

string gmstrftime(string format[, int timestamp])

Formats a GMT timestamp. See strftime for more information on how to use this function.

header

void header(string header[, bool replace])

Sends header as a raw HTTP header string; must be called before any output is generated (including blank lines, a common mistake). If the header is a Location header, PHP also generates the appropriate REDIRECT status code. If replace is specified and false, the header does not replace a header of the same name; otherwise, the header replaces any header of the same name.

headers_sent

bool headers_sent( )

Returns true if the HTTP headers have already been sent. If they have not yet been sent, the function returns false.

hebrev

string hebrev(string string[, int size])

Converts the logical Hebrew text string to visual Hebrew text. If the second parameter is specified, each line will contain no more than size characters; the function attempts to avoid breaking words.

hebrevc

string hebrev(string string[, int size])

Performs the same function as hebrev( ), except that in addition to converting string, newlines are converted to <br>\n. If specified, each line will contain no more than size characters; the function attempts to avoid breaking words.

highlight_file

bool highlight_file(string filename)

Prints a syntax-colored version of the PHP source file filename using PHP's built-in syntax highlighter. Returns true if filename exists and is a PHP source file; otherwise, returns false.

highlight_string

bool highlight_string(string source)

Prints a syntax-colored version of the string source using PHP's built-in syntax highlighter. Returns true if successful; otherwise, returns false.

hexdec

int hexdec(string hex)

Converts hex to its decimal value. Up to a 32-bit number, or 2,147,483,647 decimal (0x7FFFFFFF hexadecimal), can be converted.

htmlentities

string htmlentities(string string[, int style)

Converts all characters in string that have special meaning in HTML and returns the resulting string. All entities defined in the HTML standard are converted. If supplied, style determines the manner in which quotes are translated. The possible values for style are:

 

ENT_COMPAT (default)

 

Converts double quotes, but not single quotes

 

ENT_NOQUOTES

 

Does not convert either double quotes or single quotes

 

ENT_QUOTES

 

Converts both single and double quotes

htmlspecialchars

string htmlspecialchars(string string[, int style])

Converts characters in string that have special meaning in HTML and returns the resulting string. A subset of all HTML entities covering the most common characters is used to perform the translation. If supplied, style determines the manner in which quotes are translated. The characters translated are:

The possible values for style are:

 

ENT_COMPAT (default)

 

Converts double quotes, but not single quotes

 

ENT_NOQUOTES

 

Does not convert either double quotes or single quotes

 

ENT_QUOTES

 

Converts both single and double quotes

ignore_user_abort

int ignore_user_abort([bool ignore])

Sets whether the client disconnecting from the script should stop processing of the PHP script. If ignore is true, the script will continue processing, even after a client disconnect. Returns the current value; if ignore is not given, the current value is returned without a new value being set.

implode

string implode(array strings, string separator)

Returns a string created by joining every element in strings with separator.

import_request_variables

bool import_request_variables(string types[, string prefix])

Imports GET, POST, and cookie variables into the global scope. The types parameter defines which variables are imported, and in which order—the three types are "g" or "G", "p" or "P", and "c" or "C". For example, to import POST and cookie variables, with cookie variables overwriting POST variables, types would be "cp". If given, the variable names are prefixed with prefix. If prefix is not specified or is an empty string, a notice-level error is sent due to the possible security hazard.

in_array

bool in_array(mixed value, array array[, bool strict])

Returns true if the given value exists in the array. If the third argument is provided and is true, the function will return true only if the element exists in the array and has the same type as the provided value (that is, "1.23" in the array will not match 1.23 as the argument). If the argument is not found in the array, the function returns false.

ini_alter

string ini_alter(string variable, string value)

This function is an alias for ini_set( ).

ini_get

string ini_get(string variable)

Returns the value for the configuration option variable. If variable does not exist, returns false.

ini_restore

string ini_restore(string variable)

Restores the value for the configuration option variable. This is done automatically when a script completes execution for all configuration options set using ini_set( ) during the script.

ini_set

string ini_set(string variable, string value)

Sets the configuration option variable to value. Returns the previous value if successful or false if not. The new value is kept for the duration of the current script and is restored after the script ends.

intval

int intval(mixed value[, int base])

Returns the integer value for value using the optional base base (if unspecified, base 10 is used). If value is a nonscalar value (object or array), the function returns 0.

ip2long

int ip2long(string address)

Converts a dotted (standard format) IP address to an IPv4 address.

iptcparse

array iptcparse(string data)

Parses the IPTC (International Press Telecommunications Council) data block data into an array of individual tags with the tag markers as keys. Returns false if an error occurs or if no IPTC data is found in data.

is_array

bool is_array(mixed value)

Returns true if value is an array; otherwise, returns false.

is_bool

bool is_bool(mixed value)

Returns true if value is a Boolean; otherwise, returns false.

is_dir

bool is_dir(string path)

Returns true if path exists and is a directory; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_double

bool is_double(mixed value)

Returns true if value is a double; otherwise, returns false.

is_executable

bool is_executable(string path)

Returns true if path exists and is executable; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_file

bool is_file(string path)

Returns true if path exists and is a file; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_float

bool is_float(mixed value)

This function is an alias for is_double( ).

is_int

bool is_int(mixed value)

This function is an alias for is_long( ).

is_integer

bool is_integer(mixed value)

This function is an alias for is_long( ).

is_link

bool is_link(string path)

Returns true if path exists and is a symbolic link file; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_long

bool is_long(mixed value)

Returns true if value is an integer; otherwise, returns false.

is_null

bool is_null(mixed value)

Returns true if value is null—that is, is the keyword NULL; otherwise, returns false.

is_numeric

bool is_numeric(mixed value)

Returns true if value is an integer, a floating-point value, or a string containing a number; otherwise, returns false.

is_object

bool is_object(mixed value)

Returns true if value is an object; otherwise, returns false.

is_readable

bool is_readable(string path)

Returns true if path exists and is readable; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_real

bool is_real(mixed value)

This function is an alias for is_double( ).

is_resource

bool is_resource(mixed value)

Returns true if value is a resource; otherwise, returns false.

is_scalar

bool is_scalar(mixed value)

Returns true if value is a scalar value—an integer, Boolean, floating-point value, resource, or string. If value is not a scalar value, the function returns false.

is_string

bool is_string(mixed value)

Returns true if value is a string; otherwise, returns false.

is_subclass_of

bool is_subclass_of(object object, string class)

Returns true if object is an instance of the class class or is an instance of a subclass of class. If not, the function returns false.

is_uploaded_file

bool is_uploaded_file(string path)

Returns true if path exists and was uploaded to the web server using the file element in a web page form; otherwise, returns false. See Chapter 7 for more information on using uploaded files.

is_writable

bool is_writable(string path)

Returns true if path exists and is a directory; otherwise, returns false. This information is cached; you can clear the cache with clearstatcache( ).

is_writeable

bool is_writeable(string path)

This function is an alias for is_writable( ).

isset

bool isset(mixed value)

Returns true if value, a variable, has been set; if the variable has never been set, or has been unset( ), the function returns false.



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