PHP File Handling
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:
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
|
Note: If the fopen() function is unable to open the specified file, it returns 0 (false).
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>
|
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);
?>
|
Reading from a File
The feof() function is used to determine if the end of file is true.Note: You cannot read from files opened in w, a, and x mode!
if (feof($f))
echo "End of file";
|
Reading a Character
The fgetc() function is used to read a single character from a file.Note: After a call to this function the file pointer has moved to the next character.
Example
The example below reads a file character by character, until the end of file is true:<?php
$f=fopen("welcome.txt","r") or exit("Unable to open file!");
while (!feof($f))
{
$x=fgetc($f);
echo $x;
}
fclose($f);
?>
|
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