PHP read file Various methods and examples tutorial

Share the PHP read the file in eight ways, collected a lot of PHP read file examples, small and classic, is to learn PHP file operation good information.

There are several ways to read files in PHP.
1.fread
string fread (int $handle, int $length)
Fread () reads up to length bytes from a file pointed to by handle. The function stops reading the file when it has read up to the maximum length of bytes, or when it reaches EOF, or (for a network stream) when a package is available, or when 8,192 bytes have been read (after opening a stream of user space), depending on which situation is encountered first.
Fread () returns the read string if an error returns FALSE.
<?php
$filename = "/usr/local/something.txt";
$handle = fopen ($filename, "R");//The second parameter needs to be set to ' RB ' when reading a binary file

Get the file size by FileSize and read the entire file into a string
$contents = Fread ($handle, FileSize ($filename));
Fclose ($handle);
?>
You cannot use this method if the file you are reading is not a local normal file, but a remote file or a stream file, because FileSize cannot get the size of these files. At this point, you need to determine whether the end of the file has been read by the return value of feof () or fread ().
　　
For example:
<?php
$handle = fopen (' http://www.jbxue.com ', ' R ');
$content = ";
while (!feof ($handle)) {
$content. = Fread ($handle, 8080);
}
Echo $content;
Fclose ($handle);
?>
Or:
<?php
$handle = fopen (' http://www.jbxue.com ', ' R ');
$content = ";
while (false! = ($a = fread ($handle, 8080))) {//returns false to indicate that the end of the file has been read
$content. = $a;
}
Echo $content;
Fclose ($handle);
?>
2.fgets
String fgets (int $handle [, int $length])
Fgets () reads a row from the file pointed to by handle and returns a string up to length-1 bytes in length. Stop after encountering a newline character (included in the return value), EOF, or having read the length-1 byte (see first the case). If length is not specified, the default is 1 K, or 1024 bytes.
<?php
$handle = fopen ('./file.txt ', ' R ');
while (!feof ($handle)) {
Echo fgets ($handle, 1024);
}
Fclose ($handle);
?>
The note:length parameter becomes optional from PHP 4.2.0, and if omitted, the length of the line is assumed to be 1024. starting with PHP 4.3, ignoring length will continue to read data from the stream until the end of the line. If most of the rows in the file are larger than 8KB, specifying the length of the largest row in the script is more efficient with resources. Starting with PHP 4.3 This function can be used safely in binary files. The earlier versions were not.
3.fgetss
String Fgetss (Resource $handle [, int $length [, String $allowable _tags]])
As with the Fgets function, but FGETSS tries to remove any HTML and PHP tags from the text that is being read, you can specify which tags are not removed with the optional third parameter.
<?php
$handle = fopen ('./file.txt ', ' R ');
while (!feof ($handle)) {
Echo fgetss ($handle, 1024x768, ' <br> ');
}
Fclose ($handle);
?>
4.file
Array file (string $filename [, int $use _include_path [, Resource $context]])
Reads the contents of a file into an array, each of which corresponds to a line in the file, including newline characters. You can use the RTrim () function to filter line breaks when you don't need a line terminator.
<?php
$a = File ('./file.txt ');
foreach ($a as $line = = $content) {
Echo ' line '. ($line + 1). ': ' $content;
}
?>
5.readfile
int ReadFile (string $filename [, bool $use _include_path [, Resource $context]])
Reads a file and writes to the output buffer. Returns the number of bytes read from the file. If an error returns false and the error message is displayed unless it is called in the form of @readfile ().
<?php
$size = ReadFile ('./file.txt ');
Echo $size;
?>
6.file_get_contents
String file_get_contents (String $filename [, bool $use _include_path [, Resource $context [, int $offset [, int $maxlen] ]]] )
Reads a file into a string. The third parameter, $context, can be used to set parameters such as setting timeouts when accessing remote files, and so on.
In addition, File_get_contents has a much better performance than several of these functions, so it should be preferable to use file_get_contents. But ReadFile looks better than file_get_contents (? ), because it does not need to call fopen.
<?php
$ctx = stream_context_create (Array (
' http ' = = Array (
' Timeout ' = 1//Set timeout
)
)
);
Echo file_get_contents ("http://www.jbxue.com/", 0, $ctx);
?>

Articles you may be interested in:

• Summary of common methods for reading files in PHP
• PHP file Programming (ii)-Four ways to read files
• Code that PHP reads the contents of a file into a string and processes it
• Learn how PHP reads the contents of a file

7.fpassthru
Int Fpassthru (resource $handle)
reads the given file pointer from the current location to EOF and writes the result to the output buffer.

<?php
Header ("Content-type:text/html;charset=utf-8");
$handle = fopen ('./test2.php ', ' R ');
Fseek ($handle, 1024);//Position the pointer at 1024 bytes
Fpassthru ($handle);
?
8.parse_ini_file
Array parse_ini_file (string $filename [, bool $process _sections])
Parse_ini_file () Loads an INI file specified by filename and returns the settings as a union array. If you set the last process_sections parameter to TRUE, you will get a multidimensional array that includes the name and settings of each section in the configuration file. The default value for Process_sections is FALSE.
Note:
1. If the value in the INI file contains any non-alphanumeric characters, you need to enclose it in double quotation marks (").
2. Some reserved words cannot be used as key names in the INI file, including: Null,yes,no,true and false. A value of Null,no and false is equivalent to "", and a value of Yes and true is equivalent to "1". Character {}|&~! [() "also cannot be used anywhere in the key name, and these characters have a special meaning in the option value.
Test.ini file contents:
; This is a sample configuration file
; Comments start with '; ', as in php.ini
[first_section]
one = 1
five = 5
animal = BIRD
[second_section]
P Ath = "/usr/local/bin"
URL = "Http://www.example.com/~username
test.php content:

<?php
$config = Parse_ini_file ('./test.ini ', ture);
Print_r ($config);
?
Output content:
Array
(
[first_section] + array
(
[one] + 1
[five] + 5
[Animal] = BIRD
)
[second_section] = Array
(
[path] +/usr/local/bin
[URL] = http://www.example.com/ ~username
)
)
Several caveats:
1. Encourage the use of the B flag when working with binary files, even if the system does not require it, to make the script more portable. The
2. Allow_url_fopen option activates the URL form of the fopen encapsulation protocol so that URL objects such as files can be accessed. The default encapsulation protocol provides access to remote files with FTP and HTTP protocols, and some extension libraries such as zlib may register more encapsulation protocols. For security reasons, this option can only be set in php.ini.
3. If you want to open a URL with special characters (for example, a space), you need to use UrlEncode () for URL encoding.