PHP/File Directory/fgets

Checking for an error from fopen(), fgets(), or fclose()

 
<?
$fh = fopen("data.txt","rb");
if (! $fh) {
    print "Error opening people.txt: $php_errormsg";
} else {
    for ($line = fgets($fh); ! feof($fh); $line = fgets($fh)) {
        if ($line === false) {
            print "Error reading line: $php_errormsg";
        } else {
            $line = trim($line);
            $info = explode("|", $line);
            print "<li><a href="mailto:" . $info[0] . "">" . $info[1] ."</li>\n";
        }
    }
    if (! fclose($fh)) {
        print "Error closing people.txt: $php_errormsg";
    }
}
?>
//data.txt
a@example.ru|Alice
b@example.org|Bill
c@example.ru|Charlie
d@example.ru|Lewis

Counting paragraphs in a file

 
<?php
$paragraphs = 0;
if ($fh = fopen("great-american-novel.txt","r")) {
  while (! feof($fh)) {
    $s = fgets($fh);
    if (("\n" == $s) || ("\r\n" == $s)) {
      $paragraphs++;
    }
  }
}
print $paragraphs;
?>

Counting records in a file

 
<?php
$records = 0;
$record_separator = "--end--";
if ($fh = fopen("great-american-textfile-database.txt","r")) {
  while (! feof($fh)) {
    $s = rtrim(fgets($fh));
    if ($s == $record_separator) {
      $records++;
    }
  }
}
print $records;
?>

Creating and Using a File Class

 
<?php 
// Copyright 2005, Lee Babin (lee@thecodeshoppe.ru) 
// This code may be used and redistributed without charge 
// under the terms of the GNU General Public 
// License version 2.0 or later -- www.gnu.org 
// Subject to the retention of this copyright 
// and GPL Notice in all copies or derived works 

class cfile { 
    //The path to the file you want to work with. 
    protected $thepath; 
    
    
    //Error messages in the form of constants for ease of use. 
    const FOUNDERROR = "Sorry, the file in question does not exist."; 
    const PERMERROR = "Sorry, you do not have the proper permissions on this file"; 
    const OPENERROR = "Sorry, the file in question could not be opened."; 
    const CLOSEERROR = "Sorry, the file could not be closed."; 
    
    
    //The constructor function. 
    public function __construct (){ 
        $num_args = func_num_args(); 
        
        if($num_args > 0){ 
            $args = func_get_args(); 
            $this->thepath = $args[0]; 
        } 
    } 

    //A function to open the file. 
    private function openfile ($readorwrite){ 
    //First, ensure the file exists. 
    try { 
        if (file_exists ($this->thepath)){ 
            //Now, you need to see if you are reading or writing or both. 
            $proceed = false; 
            if ($readorwrite == "r"){ 
                if (is_readable($this->thepath)){ 
                    $proceed = true; 
                } 
            } elseif ($readorwrite == "w"){ 
                if (is_writable($this->thepath)){ 
                    $proceed = true; 
                } 
            } else { 
                if (is_readable($this->thepath) && is_writable($this->thepath)){ 
                    $proceed = true; 
                } 
            } 
            try { 
                if ($proceed){ 
                    //You can now attempt to open the file. 
                    try { 
                        if ($filepointer = fopen ($this->thepath, $readorwrite)){ 
                            return $filepointer; 
                        } else { 
                            throw new exception (self::OPENERROR); 
                            return false; 
                        } 
                    } catch (exception $e) { 
                        echo $e->getmessage(); 
                    } 
                } else { 
                    throw new exception (self::PERMERROR); 
                } 
            } catch (exception $e) { 
                echo $e->getmessage(); 
            } 
        } else { 
            throw new exception (self::FOUNDERROR); 
        } 
    } catch (exception $e) { 
        echo $e->getmessage(); 
    } 
    } 
    
    //A function to close a file. 
    function closefile () { 
    try { 
    if (!fclose ($this->thepath)){ 
    throw new exception (self::CLOSEERROR); 
    } 
    } catch (exception $e) { 
    echo $e->getmessage(); 
    } 
    } 
    
    //A function to read a file, then return the results of the read in a string. 
    
    public function read () { 
    //First, attempt to open the file. 
    $filepointer = $this->openfile ("r"); 
    
    //Now, return a string with the read data. 
    
    
    if ($filepointer != false){ 
    //Then you can read the file. 
    return fread ($filepointer,filesize ($this->thepath)); 
    
    } 
    
    //Lastly, close the file. 
    $this->closefile (); 
    } 
    
    
    //A function to write to a file. 
    
    public function write ($towrite) { 
    //First, attempt to open the file. 
    $filepointer = $this->openfile ("w"); 
    
    
    //Now, return a string with the read data. 
    
    if ($filepointer != false){ 
    //Then you can read the file. 
    return fwrite ($filepointer, $towrite); 
    
    
    } 
    
    //Lastly, close the file. 
    $this->closefile (); 
    } 
    
    
    //A function to append to a file. 
    
    public function append ($toappend) { 
    //First, attempt to open the file. 
    $filepointer = $this->openfile ("a"); 
    
    
    //Now, return a string with the read data. 
    
    if ($filepointer != false){ 
    //Then you can read the file. 
    return fwrite ($filepointer, $toappend); 
    
    
    } 
    
    //Lastly, close the file. 
    $this->closefile (); 
    } 
    
    
    //A function to set the path to a new file. 
    public function setpath ($newpath) { 
    $this->thepath = $newpath; 
    } 
    
} 
?> 

<?php 
//Include the class. 
require_once ("file.class.inc.php"); 
//Then create a new instance of the class. 
$myfile = new cfile ("data.txt"); 
//Now, let"s try reading it. 
echo $myfile->read(); 

//Then let"s try writing to the file. 
$myfile->write ("Hello World!"); 

//Then, let"s try appending. 
$myfile->append ("Hello Again!"); 

?>

fgets() function returns a string read from a file.

 
Its syntax is: string fgets (int filepointer, int length)
<?
$fh = fopen("data.txt", "r");
while (! feof($fh)) :
     $line = fgets($fh, 4096);
     print $line."<br>";
endwhile;
fclose($fh);
?>

fgets.php

 
<?php
   $fh = fopen("/home/www/data/users.txt", "rt");
   while (!feof($fh)) echo fgets($fh);
   fclose($fh);
?>

Processing a list of books

 
<?php
$fh = fopen("books.txt","r") or die("can"t open: $php_errormsg");
while (! feof($fh)) {
    $s = rtrim(fgets($fh));
    list($title,$author,$publication_year) = explode("|",$s);
}
fclose($fh) or die("can"t close: $php_errormsg");
?>

Processing each word in a file

 
<?php
$fh = fopen("novel.txt","r") or die($php_errormsg);
while (! feof($fh)) {
    if ($s = fgets($fh)) {
        $words = preg_split("/\s+/",$s,-1,PREG_SPLIT_NO_EMPTY);
    }
}
fclose($fh) or die($php_errormsg);
?>

Reading a compressed file

 
<?php
$fh = fopen("compress.zlib://lots-of-data.gz","r") or die("can"t open: $php_errormsg");
while ($line = fgets($fh)) {
    // $line is the next line of uncompressed data
}
fclose($fh) or die("can"t close: $php_errormsg");
?>

Reading a file a line at a time

 
<?
$fh = fopen("people.txt","rb");
for ($line = fgets($fh); ! feof($fh); $line = fgets($fh)) {
    $line = trim($line);
    $info = explode("|", $line);
    print "<li><a href="mailto:" . $info[0] . "">" . $info[1] ."</li>\n";
}
fclose($fh);
?>
//people.txt
a@example.ru|Alice
b@example.org|Bill
c@example.ru|Charlie
d@example.ru|Lewis