PHP/File Directory/fopen
Содержание
- 1 Acceptable fopen() Modes
- 2 Calling fopen() with a Context Resource
- 3 File open with exception checking
- 4 fopen() function opens a file, returns an integer, as a file handle.
- 5 fopen() requires the file path and the mode in which the file is to be opened.
- 6 fopen() returns false if the file cannot be opened for any reason.
- 7 Getting and Printing a Web Page with fopen()
- 8 Getting and Putting Files with FTP
- 9 If you are writing a binary file on a Windows system, you should add a "b" flag.
- 10 Load remote file
- 11 Open a connection with the PHP site (http://www.php.net):
- 12 Opening a file
- 13 Opening a file on Windows
- 14 Opening a remote file
- 15 Opening Files
- 16 Opening files in the include_path
- 17 PHP 5 Arguments for Opening a File
- 18 Reading a File with fread()
- 19 Reading from standard input
- 20 Safely reading a binary file
- 21 Using fopen( )
- 22 Using the fopen() Function
Acceptable fopen() Modes
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r Open the file for reading.
r+ Open the file for reading and writing.
w Open the file for writing, overwriting existing files, and creating the file if it does not exist.
w+ Open the file for reading and writing, overwriting existing files, and creating the file if it does not exist.
a Open the file for writing, creating the file if it does not exist, and appending to the file if it does.
a+ Open the file for reading and writing, creating the file if it does not exist, and appending to the file if it does.
b Open the file in binary reading/writing mode (applicable only on Windows systems; however, recommended in all scripts).
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Calling fopen() with a Context Resource
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<?php $url = "http://www.wbex.ru/index.htm"; $options = array ("http" => array ("user_agent" => "php24-test-script", "header" => "referer: http://www.example.ru/index.html\r\n" ) ); $context = stream_context_create ( $options ); $res = fopen ( $url, "r", 0, $context ) or die ( "could not open page" ); while ( ! feof ( $res ) ) {
print fgets ( $res, 1024 );
} ?>
</source>
File open with exception checking
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<?php try {
$fh = fopen("data.txt", "r");
if (! $fh) {
throw new Exception("Could not open the file!");
}
} catch (Exception $e) {
echo "Error (File: ".$e->getFile().", line ".
$e->getLine()."): ".$e->getMessage();
} ?>
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fopen() function opens a file, returns an integer, as a file handle.
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Its syntax is: int fopen (string file, string mode [, int use_include_path]) The mode specifies the read/write readiness of the file. MODE MEANING r Read only. r+ Reading and writing. w Write only. w+ Reading and writing. a Write only. a+ Reading and writing.
If use_include_path is set to 1, file path is compared to the include path contained in the php.ini file. <?
$file = "data.txt"; // some file
$fh = fopen($file, "a+") or die("File ($file) does not exist!");
?>
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fopen() requires the file path and the mode in which the file is to be opened.
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The most common modes are read ("r"), write ("w"), and append ("a"). fopen() returns a file resource you will later use to work with the open file. To open a file for reading, you would use the following: $fp = fopen( "test.txt", "r" );
You would use the following to open a file for writing:
$fp = fopen( "test.txt", "w" );
To open a file for appending, you would use this:
$fp = fopen( "test.txt", "a" );
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fopen() returns false if the file cannot be opened for any reason.
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if ( $fp = fopen( "test.txt", "w" ) ) {
// do something with $fp
} Or you can use a logical operator to end execution if an essential file can"t be opened:
( $fp = fopen( "test.txt", "w" ) ) or die ("Couldn"t open file, sorry");
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Getting and Printing a Web Page with fopen()
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<html> <head> <title>Getting a Web Page with fopen()</title> </head> <body>
<?php $webpage = "http://www.wbex.ru/index.htm"; $fp = fopen( $webpage, "r" ) or die("couldn"t open $webpage"); while ( ! feof( $fp )) {
print fgets( $fp, 1024 );
} ?>
</body> </html>
</source>
Getting and Putting Files with FTP
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<?php $file_name = "somefile.ext"; $fp = fopen($file_name, "rb"); if ($fp) {
$data = fread($fp, filesize($file_name)); fclose($fp);
} ?>
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If you are writing a binary file on a Windows system, you should add a "b" flag.
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$fp = fopen( "binary_file", "wb" ); and read them like this: $fp = fopen( "binary_file", "rb" );
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Load remote file
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<?php $file_name = "http://php.net/index.php"; $fp = fopen ( $file_name, "r" ); if ($fp) {
$data = "";
while ( ! feof ( $fp ) ) {
$data .= fread ( $fp, 4096 );
}
fclose ( $fp );
} echo $data; ?>
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Open a connection with the PHP site (http://www.php.net):
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<?
$site = "http://www.php.net"; // some server that can communicate via HTTP $sh = fopen($site, "r"); // assigns PHP.net index page to a filehandle.
?>
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Opening a file
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<?php $fh = fopen("file.txt","r") or die("can"t open file.txt: $php_errormsg"); ?>
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Opening a file on Windows
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$fh = fopen("c:/settings.txt","rb");
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Opening a remote file
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<?php $fh = fopen("http://www.example.ru/robots.txt","r") or die($php_errormsg); ?>
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Opening Files
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<?php $file = "data.txt"; if (file_exists ($file)){
try {
if ($readfile = fopen ($file, "r")){
echo "File opened successfully.";
} else {
throw new exception ("Sorry, the file could not be opened.");
}
} catch (exception $e) {
echo $e->getmessage();
}
} else {
echo "File does not exist.";
} ?>
</source>
Opening files in the include_path
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<?php $fh = fopen("file.inc","r",true) or die("can"t open file.inc: $php_errormsg"); ?>
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PHP 5 Arguments for Opening a File
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Argument Description r Opens a file for reading r+ Opens a file for both reading and writing w Opens a file for writing only w+ Opens a file for reading and writing a Opens a file for appending (write-only) a+ Opens a file for appending (read/write) X Creates a file and opens it for writing only x+ Creates a file and opens it for reading and writing
<?php $file = "data.txt"; if (file_exists ($file)){
try {
if ($readfile = fopen ($file, "r")){
$curvalue = fread ($readfile,100);
echo $curvalue;
} else {
throw new exception ("the file could not be opened.");
}
} catch (exception $e) {
echo $e->getmessage();
}
} else {
echo "File does not exist.";
} ?>
</source>
Reading a File with fread()
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<html> <head> <title>Reading a File with fread()</title> </head> <body>
<?php $filename = "data.txt"; $fp = fopen( $filename, "r" ) or die("Couldn"t open $filename"); while ( ! feof( $fp ) ) {
$chunk = fread( $fp,16 ); print "$chunk
";
} ?>
</body> </html>
</source>
Reading from standard input
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<?php $fh = fopen("php://stdin","r") or die($php_errormsg); while($s = fgets($fh)) {
print "You typed: $s";
} ?>
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Safely reading a binary file
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<?php $fh = fopen("c:/images/logo.gif","rb"); ?>
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Using fopen( )
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<?
$fp = fsockopen ("data.org", 80);
if ($fp) {
fwrite($fp, "GET / HTTP/1.1\r\nHOST: data.org\r\n
ACCEPT-ENCODING: gzip\r\n\r\n");
while (!feof($fp)) {
print fread($fp,256);
}
fclose ($fp);
} else {
print "Fatal error\n";
}
?>
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Using the fopen() Function
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<?php
$fr = fopen("myfile.txt", "r");
$fr = fopen("myfile.dat", "ba+");
$fr = fopen("code.php", "w+", true);
$fr = fopen("http://www.php.net/index.php", "r");
$fr = fopen("ftp://ftp.php.net/index.php", "r");
$url = "http://www.php.net/this is my invalid URL.php";
$url = urlencode($url);
$fr = fopen($url, "r");
?>
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