Opening a File
The fopen() function is used to open files in PHP.
The first parameter of this function contains the name of the file to be opened and the second parameter specifies in which mode the file should be opened:
<html>
<body>
<?php
$file=fopen("welcome.txt","r");
?>
</body>
</html>
The file may be opened in one of the following modes:
Note: If the fopen() function is unable to open the specified file, it returns 0 (false).
<body>
<?php
$file=fopen("welcome.txt","r");
?>
</body>
</html>
The file may be opened in one of the following modes:
| Modes | Description |
|---|---|
| r | Read only. Starts at the beginning of the file |
| r+ | Read/Write. Starts at the beginning of the file |
| w | Write only. Opens and clears the contents of file; or creates a new file if it doesn't exist |
| w+ | Read/Write. Opens and clears the contents of file; or creates a new file if it doesn't exist |
| a | Append. Opens and writes to the end of the file or creates a new file if it doesn't exist |
| a+ | Read/Append. Preserves file content by writing to the end of the file |
| x | Write only. Creates a new file. Returns FALSE and an error if file already exists |
| x+ | Read/Write. Creates a new file. Returns FALSE and an error if file already exists |
Example
The following example generates a message if the fopen() function is unable to open the specified file: <html>
<body>
<?php
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
?>
</body>
</html>
<body>
<?php
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
?>
</body>
</html>
Closing a File
The fclose() function is used to close an open file: <?php
$file = fopen("test.txt","r");
//some code to be executed
fclose($file);
?>
The feof() function is useful for looping through data of unknown length.
Note: You cannot read from files opened in w, a, and x mode!
$file = fopen("test.txt","r");
//some code to be executed
fclose($file);
?>
Check End-of-file
The feof() function checks if the "end-of-file" (EOF) has been reached.The feof() function is useful for looping through data of unknown length.
Note: You cannot read from files opened in w, a, and x mode!
if (feof($file)) echo "End of file";
Note: After a call to this function the file pointer has moved to the next line.
Reading a File Line by Line
The fgets() function is used to read a single line from a file.Note: After a call to this function the file pointer has moved to the next line.
Example
The example below reads a file line by line, until the end of file is reached: <?php
$file = fopen("welcome.txt", "r") or exit("Unable to open file!");
//Output a line of the file until the end is reached
while(!feof($file))
{
echo fgets($file). "<br />";
}
fclose($file);
?>
Note: After a call to this function the file pointer moves to the next character.
$file = fopen("welcome.txt", "r") or exit("Unable to open file!");
//Output a line of the file until the end is reached
while(!feof($file))
{
echo fgets($file). "<br />";
}
fclose($file);
?>
Reading a File Character by Character
The fgetc() function is used to read a single character from a file.Note: After a call to this function the file pointer moves to the next character.
Example
The example below reads a file character by character, until the end of file is reached: <?php
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
while (!feof($file))
{
echo fgetc($file);
}
fclose($file);
?>
http://www.w3schools.com/php/php_file.asp
$file=fopen("welcome.txt","r") or exit("Unable to open file!");
while (!feof($file))
{
echo fgetc($file);
}
fclose($file);
?>
PHP Filesystem Reference
For a full reference of the PHP filesystem functions, visit our PHP Filesystem Reference.http://www.w3schools.com/php/php_file.asp
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