Introduction
In this article I describe the PHP FileSystem functions ftell, ftruncate, fwrite and glob. To learn some other FileSystem functions, go to:
- FileSystem Function in PHP: PART 1
- FileSystem Function in PHP: PART 2
- FileSystem Function in PHP: PART 3
- FileSystem Function in PHP: PART 4
- FileSystem Function in PHP: PART 5
- FileSystem Function in PHP: PART 6
- FileSystem Function in PHP: PART 7
- FileSystem Function in PHP: PART 8
- FileSystem Function in PHP: PART 9
- FileSystem Function in PHP: PART 10
PHP ftell() Function
The PHP FileSystem ftell function is used to fetch the current position of the file pointer of an open file and it returns the current position in an open file.
Syntax
Parameters in ftell function
The parameter of the function is:
| Parameter |
Description |
| file |
It specifies the open file to check. |
Example of ftell function
An example of the function is:
<?php
$file = fopen("test.txt","r");
echo ftell($file);
fseek($file,"15");
// print current position again
echo "<br />" . ftell($file);
fclose($file);
?>
Output
![ftell-function-in-php.jpg]()
PHP ftruncate() Function
The PHP FileSystem ftruncate function is used to truncates a file to a specified length and it returns true on success or false on failure.
Syntax
Parameters in ftruncate function
The parameter of the function are:
| Parameter |
Description |
| file |
It specifies the open file to truncate. |
| size |
It specifies the new file size. |
Example of ftruncate function
An example of the function is:
<?php
echo filesize("test.txt")."</br>";
$file = fopen("test.txt", "a+");
ftruncate($file,50);
fclose($file);
//Clear cache and check filesize again
clearstatcache();
echo filesize("test.txt");
?>
Output
![ftruncate-function-in-php.jpg]()
PHP fwrite() Function
The PHP FileSystem fwrite is used to write to an open file and it returns number of bytes on success or false on failure.
Syntax
| fread(file,string, length) |
Parameters in fwrite function
The parameters of the function are:
| Parameter |
Description |
| file |
It specifies the open file to truncate. |
| string |
It specifies the string to the open file. |
| length |
It specifies the maximum number of bytes to write. |
Example of fwrite function
An example of the function is:
<?php
$fileHandler = fopen("test.txt", "w");
// Write to the file
fwrite($fileHandler, "Welcome at MCNSolution!");
fclose($fileHandler);
// Access the file data and echo it
$data = file_get_contents("test.txt");
echo $data;
?>
Output
![fwrite-function-in-php.jpg]()
PHP glob() Function
The PHP FileSystem glob function returns an array of filenames or directories matching a specified pattern.
Syntax
Parameters in fwrite function
The parameters of the function are:
| Parameter |
Description |
| pattern |
It specifies the pattern to search for. |
| flag |
It specifies special settings and the possible values are:
- GLOB_MARK - Adds a slash to each item returned.
- GLOB_NOSORT - Return files as they appear in the directory.
- GLOB_NOCHECK - Returns the search pattern if no match were found.
- GLOB_NOESCAPE - Backslashes do not quote metacharacters.
- GLOB_BRACE - Expands {a,b,c} to match "a", "b", or "c".
- GLOB_ONLYDIR - Return only directories that match the pattern.
- GLOB_ERR - Stop on errors.
|
Example of glob function
An example of the function is:
<?php
print_r(glob("*.txt"));
?>
Output
![glob-function-in-php.jpg]()