FileSystem Function in PHP: PART 8

Introduction

In this article I describe the PHP FileSystem functions filesize, filetype, flock and fnmatch. To learn some other FileSystem functions, go to:

  1. FileSystem Function in PHP: PART 1
  2. FileSystem Function in PHP: PART 2
  3. FileSystem Function in PHP: PART 3
  4. FileSystem Function in PHP: PART 4
  5. FileSystem Function in PHP: PART 5
  6. FileSystem Function in PHP: PART 6
  7. FileSystem Function in PHP: PART 7

PHP filesize() Function

The PHP filesize function gets the file size, in other words it returns the file size in bytes on success or false on failure.

Syntax

filesize(filename)

Parameter in filesize function

The parameter of the function is:

Parameter Description
filename It specifies the file to check.

Example

An example of the
function is:

<?
php
echo
filesize("test.txt");
?>


Output


file-size-function-in-php.gif

PHP filetype() Function

The PHP filetype function gets the type of file, basically this function returns one of the seven possible values on success or false on failure.

Values are:

Possible return values:

  • fifo
  • char
  • dir
  • block
  • link
  • file
  • unknown

Syntax

filetype(filename)

Parameter in filetype function

The parameters of the function is:

Parameter Description
filename It specifies the file to check.

Example

An example of the
function is:

<?
php
echo
filetype("test.txt")
?>


Output


file-type-function-in-php.gif

PHP flock() Function

The PHP flock function  provides a file locking capability that allows you to read from and write to a file and it return true on success and false on failure.

Syntax

flock(file,lock,block)

Parameter in flock function

The parameters of the function are:

Parameter Description
file It specifies an open file to lock or relase.
lock It specifies what kind of lock to use.

values are:
  • LOCK_EX - Exclusive lock (writer), prevents other processes from accessing the file.
  • LOCK_UN - Release a shared or exclusive lock
  • LOCK_SH - Shared lock (reader), allows other processes to access the file
block The optional thrid argument is set to TRUE if the lock should block.

Example

An example of the
function is:

<?
php
$
file = fopen("test.txt","w+");
if (flock($file,LOCK_SH))
{
fwrite($file,"
Welcome at MCN Solution!");
}
else
{
echo "
locking  problem in file";
}

?>


PHP fnmatch() Function

The filesystem fnmatch function matches a filename against a pattern and it returns true if there is match else it returns false.

Syntax

fnmatch(pattern,string,flag)

Parameter in fnmatch function

The parameters of the function are:

Parameter Description
pattern It specifies the pattern to search for.
string It specifies the string or file check.
flag It is an optional parameter and the value of flag mya be any combination of the following flags:
  • FNM_NOESCAPE - Disable backslash escaping.
  • FNM_PATHNAME - Slash in string only matches slash in the given pattern.
  • FNM_PERIOD - Leading period in string must be exactly matched by period in the given pattern.
  • FNM_CASEFOLD - Caseless match. Part of the GNU extension.

Example

An example of the
function is:

<?
php
$
str= "Work is Worship !";
if
(fnmatch("*gr[ae]y", $str)) {
echo
"It is fnmatch function ...";
}

?>

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