PHP: fscanf - Manual

Description

mixed fscanf ( resource handle, string format [, mixed &...] )

The function fscanf() is similar to sscanf(), but it takes its input from a file associated with handle and interprets the input according to the specified format, which is described in the documentation for sprintf(). If only two parameters were passed to this function, the values parsed will be returned as an array. Otherwise, if optional parameters are passed, the function will return the number of assigned values. The optional parameters must be passed by reference.

Any whitespace in the format string matches any whitespace in the input stream. This means that even a tab \t in the format string can match a single space character in the input stream.

Example 1. fscanf() Example

<?php $handle = fopen("users.txt", "r"); while ($userinfo = fscanf($handle, "%s\t%s\t%s\n")) { list ($name, $profession, $countrycode) = $userinfo; //... do something with the values } fclose($handle); ?>

Example 2. Contents of users.txt
javier argonaut pe hiroshi sculptor jp robert slacker us luigi florist it

Note: Prior to PHP 4.3.0, the maximum number of characters read from the file was 512 (or up to the first \n, whichever came first). As of PHP 4.3.0 arbitrarily long lines will be read and scanned.

User Contributed Notes
fscanf

me at hesterc dot fsnet dot co dot uk
25-May-2004 09:03


I have a simpler method I use to parse delimited text. Using the data posted by gozer at fanhunter dot com, here is my script. Maybe it is faster?



<?php



$fp = fopen ("sections.dat","r");



if (!$fp) {echo "<p>Unable to open remote file.</p>"; exit;}



while (!feof($fp)):

 $line = fgets($fp, 2048);

 $out = array($line);

 list ($id, $name, $description, $language, $directory, $id_uplevel, $order, $hassubsection) = split ("\|", $out[0]);

 echo "$id-$name-$description-$language-$directory-

$id_uplevel-$order-$hassubsection<br />\n";

 $fp++;

endwhile;



fclose($fp);

?>



Notes:



Avoid the php extension on a data file - it will cause PHP to parse the file, but there is no PHP in it.



The "2048" value on line 2 of the loop is set for long lines. 1024 works fine, but I had to increase it with a large database I use a similar script to read.



You don't need to open and close the speech marks (as in gozer at fanhunter dot com's example) in the echo line, just use the variables inbetween the dashes.



(Remove the line break halfway through the echo line - it is just there for this forum.)

matt at mattsinclair dot com
21-Jan-2004 02:36


A better way to use fscanf() would be this:



<?php

$handle = fopen("users.txt", "r");

while (!feof($handle)) {

   $userinfo = fscanf($handle, "%s\t%s\t%s\n");

   if ($userinfo) {

     list ($name, $profession, $countrycode) = $userinfo;

     //... do something with the values

   }

   $userinfo=NULL;

}

fclose($handle);

?> 



as you can see, instead of waiting for fscanf() to fail to return a value... it waits for the the pointer to get to the end of the file... this way, if for some reason one of your lines does not match your expression, it will not kill the loop.  it will simply go on to the next line.

robert at NOSPAM dot NOSPAM
24-Oct-2002 06:08


actually, instead of trying to think of every character that might be in your file, excluding the delimiter would be much easier.



for example, if your delimiter was a comma use:



%[^,]



instead of:



%[a-zA-Z0-9.| ... ]



Just make sure to use %[^,\n] on your last entry so you don't include the newline.

ruiner911 at yahoo dot com
15-Aug-2002 03:01


Clear the variables before you scan them in.  As a programmer this should have been very apparent.  Goof.

eugene at pro-access dot com
16-Mar-2002 02:39


If you want to read text files in csv format or the like(no matter what character the fields are separated with), you should use fgetcsv() instead. When a text for a field is blank, fscanf() may skip it and fill it with the next text, whereas fgetcsv() correctly regards it as a blank field.

gozer at fanhunter dot com
07-Mar-2002 08:53


Hi,

A few days ago we got multiple mySQL crashes due to a hardware failure and other processes running.

While we thought it could be the mySQL daemon overloaded, we started looking for alternate ways to get our little databases working so we started using fscanf to parse files.



We ran into multiple problems due to the whitespace and other characters that were in our database. Finally, we made it to work using sets as james@zephyr-works.com remarked.



Our final function is:



  function get_sections($include_dir){

    $filename = $include_dir . "sections.dat.php";

    $datafile = fopen ($filename ,"r");

    while ($sectioninfo = fscanf ($datafile, "%[0-9]|%[a-zA-Z0-9@&;:,. /!?-]|%[a-zA-Z0-9@&;:,. /!?-]|%[a-zA-Z]|%[a-zA-Z0-9@/?&;.+=-]|%[0-9]|%[0-9]|%[0-9]\n")) {

        list($id, $name, $description, $language, $directory, $id_uplevel, $order, $hassubsection) = $sectioninfo;



        // Show output

        echo $id . "-" . $name. "-" . $description . "-" . $language . "-" . $directory . "-" . $id_uplevel . "-" . $order . "-" . $hassubsection . "<br>\n";

    }

    fclose($datafile);

  }



The contents of sections.dat.php (for example):



1|home|P&aacute;gina principal de Fanhunter.|castellano|==|0|0|0

2|fanhunter|Secci&oacute;n principal dedicada al universo Fanhunter.|castellano|fanhunter/|1|0|0

3|outfan|Secci&oacute;n principal dedicada al universo Outfan.|castellano|outfan/|1|0|0

4|fanpiro|Secci&oacute;n principal dedicada al universo Fanpiro.|castellano|fanpiro/|1|0|0

5|tienda|La tienda de Fanhunter.|castellano|tienda/|1|0|0

6|the zone|Secci&oacute;n principal Miscel&aacute;nea.|castellano|thezone/|1|0|0

7|flfcn|Secci&oacute;n principal dedicada a Fan Letal/Fan con Nata.|castellano|fanletal/|1|0|0

8|foro|Nuestro foro de discusi&oacute;n.|castellano|foro/|1|0|0

9|chat|Secci&oacute;n para chatear.|castellano|chat/|1|0|0

10|links|Secci&oacute;n recopilatoria de enlaces de inter&eacute;s a otras p&aacute;ginas.|castellano|links/|1|0|0



Note: The '==' in directory means no directory needed to be specified.

Pay attention to linebreaks, as this forum puts some of them into the code I pasted.



Good luck guys.

james at zephyr-works dot com
08-Jul-2001 02:29


fscanf works a little retardedly I've found. Instead of using just a plain %s you probably will need to use sets instead. Because it works so screwy compared to C/C++, fscanf does not have the ability to scan ahead in a string and pattern match correctly, so a seemingly perfect function call like:





fscanf($fh, "%s::%s");





With a file like:





user::password





Will not work. When fscanf looks for a string, it will look and stop at nothing except for a whitespace so :: and everything except whitespace is considered part of that string, however you can make it a little smarter by:





fscanf($fh, "%[a-zA-Z0-9,. ]::%[a-zA-Z0-9,. ]" $var1, $var2);





Which tells it that it can only accept a through z A through Z 0 through 9 a comma a period and a whitespace as input to the string, everything else cause it to stop taking in as input and continue parsing the line. This is very useful if you want to get a sentence into the string and you're not sure of exactly how many words to add, etc.

yasuo_ohgaki at hotmail dot com
13-Mar-2001 01:59


For C/C++ programmers.





fscanf() does not work like C/C++, because PHP's fscanf() move file pointer the next line implicitly.