What is File Reading?
Working with online applications frequently needs reading data from files. PHP makes it easy to read files from your server. File reading is the process of opening a file and extracting its data for usage in your program. For example, you may want to read a text file that contains user information, configuration settings or product specifications.
How to Read a File in PHP?
There are a number of options in PHP for reading data from a file that has been opened with the fopen() function. The following built-in functions in PHP’s library can help us perform the read operation −
- file_get_contents() − reads a file into a string.
- fgets() − gets a line from the file pointer.
- fgetc() − returns a string with a single character from the file pointer.
- fread() − reads a specified number of bytes from the file pointer.
- fscanf() − reads data from the file and parses it as per the specified format.
Using file_get_contents() Function
This function reads the entire file into a string. It is the simplest way to read a file.
file_get_contents($path,$include_path,$context,$start,$max_length)
Example
The following code reads the entire available content from the “myfile.txt” file −
<?php
// Specify the path to the file
$filename = 'myfile.txt';
// Read the content of the file
$content = file_get_contents($filename);
// Check if the file was read successfully
if ($content === false) {
echo "Error reading the file.";
} else {
echo "File content: " . $content;
}
?>
Output
It will produce the following output −
File content: Hello this is an example of PHP read file. This is a new line in the file.
Using fgets() Function
The fgets() function can return a line from an open file. This function stops returning on a new line at a specified length or EOF, whichever comes first and returns false on failure.
fgets(resource$stream,?int$length=null):string|false
Here, the $stream parameter is a file pointer or handle to the file opened with the fopen() function with read or read/write mode, and $length is an optional parameter specifying the number of bytes to be read.
The read operation ends when “length-1” bytes are read or a newline is encountered, whichever is first.
Example
The following code reads the first available line from the “hello.txt” file −
<?php
$file = fopen("hello.txt", "r");
$str = fgets($file);
echo $str;
fclose($file);
?>
Output
It will produce the following output −
Hello World
Example
You can put the fgets() function in a loop to read the file until the end of file is reached.
<?php
$file = fopen("hello.txt", "r");
while(! feof($file)) {
echo fgets($file). "<br>";
}
fclose($file);
?>
Output
It will produce the following output −
Hello World TutorialsPoint PHP Tutorials
Here, we have used the feof() function which returns true if the file pointer is at EOF; otherwise returns false.
Using fgetc() Function
The fgetc() function returns a single character read from the current position of the file handle. It returns false when EOF is encountered.
fgetc(resource$stream):string|false
Here, the $stream parameter is a file pointer or handle to the file opened with the fopen() function with read or read/write mode.
Example
The following code displays the first character read from the “hello.txt” file −
<?php
$file = fopen("hello.txt", "r");
$str = fgets($file);
echo $str;
fclose($file);
?>
Output
It will produce the following output −
H
Example
You can also put the fgetc() function inside a loop to read the file character by character until it reaches EOF.
<?php
$file = fopen("hello.txt", "r");
while(! feof($file)) {
$char = fgetc($file);
if ($char == "\n")
echo "<br>";
echo $char;
}
fclose($file);
?>
Output
It will produce the following output −
Hello World TutorialsPoint PHP Tutorials
Using fread() Function
The fread() function in PHP is a binary-safe function for reading data from a file. While the fgets() function reads only from a text file, the fread() function can read a file in binary mode.
fread(resource$stream,int$length):string|false
Here, the $stream parameter is a file pointer or handle to the file opened with the fopen() function with binary read or read/write mode (rb or rb+). The $length parameter specifies number of bytes to be read.
If the $length parameter is not given, PHP tries to read the entire file until EOF is reached, subject to the chunk size specified.
Example
The following code reads a text file −
<?php $name = "hello.txt"; $file = fopen($name, "r"); $data = fread($file, filesize($name)); echo $data; fclose($file); ?>
Output
It will produce the following output −
Hello World TutorialsPoint PHP Tutorials
Example
You can also read a non-ASCII file such as an image file opened in rb mode.
<?php $name = "welcome.png"; $file = fopen($name, "rb"); $data = fread($file, filesize($name)); var_dump($data); fclose($file); ?>
The browser displays the “var_dump” information as the following −
Using fscanf() Function
The fscanf() function in PHP reads the input from a file stream and parses it according to the specified format, thereby converts it into the variables of respective types. Each call to the function reads one line from the file.
fscanf(resource$stream,string$format,mixed&...$vars):array|int|false|null
Here, the $stream parameter is the handle to the file opened with the fopen() function and in read mode. And, $format is a string containing one or more of the following formatting specifiers −
- %% − Returns a percent
- %b − Binary number
- %c − The character according to the ASCII value
- %f − Floating-point number
- %F − Floating-point number
- %o − Octal number
- %s − String
- %d − Signed decimal number
- %e − Scientific notation
- %u − Unsigned decimal number
- %x − Hexadecimal number for lowercase letters
- %X − Hexadecimal number for uppercase letters
$vars is an optional parameter that specifies variables by reference which will contain the parsed values.
Assuming that the “employees.txt” file is available in the same directory in which the PHP script given below is present. Each line in the text file has name, email, post and salary of each employee, separated by tab character.
Example
The following PHP script reads the file using the format specifiers in fscanf() function −
<?php
$fp = fopen("employees.txt", "r");
while ($employee_info = fscanf($fp, "%s\t%s\t%s\t%d\n")) {
list ($name, $email, $post, $salary) = $employee_info;
echo "<b>Name</b>: $name <b>Email</b>:
$email <b>Salary</b>: Rs. $salary <br>";
}
fclose($fp);
?>
Output
It will produce the following output −
Name: Ravishankar Email: [email protected] Salary: Rs. 40000 Name: Kavita Email: [email protected] Salary: Rs. 25000 Name: Nandkumar Email: [email protected] Salary: Rs. 30000