fread
The fgetd() function suggested by worldwideroach on 14-Jul-2005 04:33 does not handle the last buffer-load of data correctly. At least not for my requirement. It is possible for EOF to have been reached but for there still to be characters in $sRecord.
For the, er... record I got better results with this version:
<?php
function fgetd(&$rFile, $sDelim, $iBuffer=1024) {
$sRecord = '';
while(!feof($rFile)) {
$iPos = strpos($sRecord, $sDelim);
if ($iPos === FALSE) {
$sRecord .= fread($rFile, $iBuffer);
} else {
fseek($rFile, 0-strlen($sRecord)+$iPos+strlen($sDelim), SEEK_CUR);
return substr($sRecord, 0, $iPos);
}
}
// Last read got some more data before hitting EOF?
if ($sRecord != '') {
if (($iPos = strpos($sRecord, $sDelim)) !== FALSE) {
fseek($rFile, 0-strlen($sRecord)+$iPos+strlen($sDelim), SEEK_CUR);
return substr($sRecord, 0, $iPos);
}
else {
return $sRecord;
}
}
else {
return FALSE;
}
}
?>
fscanf
(PHP 4 >= 4.0.1, PHP 5)
fscanf — Analiza la entrada desde un archivo de acuerdo a un formato
Descripción
La función fscanf() es similar a
sscanf(), excepto que toma su entrada desde un archivo
asociado con handle e interpreta la
entrada de acuerdo al parámetro format especificado, que es
descrito en la documentación de sprintf().
Cualquier espacio en blanco en la cadena de formato coincide con cualquier espacio en blanco en el flujo de entrada. Esto significa que incluso una tabulación \t en la cadena de formato puede coincidir con un simple caráter espacio en el flujo de entrada.
Cada llamada a fscanf() lee una línea del archivo.
Parámetros
Valores devueltos
Si sólo se pasaron dos parámetros a esta función, los valores analizados serán devueltos como una matriz. De otro modo, si se pasaron los parámetros opcionales, la función devolverá el número de valores asignados. Los parámetros opcionales pueden ser pasados por referencia.
Historial de cambios
| Versión | Descripción |
|---|---|
| 4.3.0 | Antes de esta verisión, el número máximo de caracteres leídos desde el archivo era 512 (o hasta el primer \n, lo que sucediera primero). Pero ahora, se pueden leer y analizar líneas de longitud arbitraria. |
Ejemplos
Ejemplo #1 Ejemplo de fscanf()
<?php
$gestor = fopen("usuarios.txt", "r");
while ($userinfo = fscanf($gestor, "%s\t%s\t%s\n")) {
list ($nombre, $profesión, $código_país) = $userinfo;
//... hacer algo con los valores
}
fclose($gestor);
?>
Ejemplo #2 Contenido de usuarios.txt
javier argonaut pe hiroshi sculptor jp robert slacker us luigi florist it
Ver también
- fread() - Lectura de un fichero en modo binario seguro
- fgets() - Obtiene un línea del puntero a un archivo
- fgetss() - Obtiene un línea desde un puntero a un archivo y elimina las etiquetas HTML
- sscanf() - Interpreta un string de entrada de acuerdo con un formato
- printf() - Imprimir una cadena con formato
- sprintf() - Devuelve un string formateado
add a note
User Contributed Notes
fscanf
dave at dave dot st
01-Jan-2009 04:58
arentzen at religion dot dk
29-Sep-2007 08:56
If you want fscanf()to scan one variable in a large number of lines, e.g an Ipadress in a line with more variables, then use fscanf with explode()
<?
$filename = "somefile.txt";
$fp = fopen($filename, "r") or die ("Error opening file! \n");
$u = explode(" ",$line); // $u is the variable eg. an IPadress
while ($line = fscanf($fp,"%s",$u)) {
if(preg_match("/^$u/",$_SERVER['REMOTE_ADDR'])) {$badipadresss++;} // do something and continue scan
}
?>
Besides, fscanf()is much faster than fgets()
Bertrand dot Lecun at prism dot uvsq dot Fr
29-May-2007 06:48
It would be great to precise in the fscanf documentation
that one call to the function, reads a complete line.
and not just the number of values defined in the format.
If a text file contains 2 lines each containing 4 integer values,
reading the file with 8 fscanf($fd,"%d",$v) doesnt run !
You have to make 2
fscanf($fd,"%d %d %d %d",$v1,$v2,$v3,$v4);
Then 1 fscanf per line.
loco.xxx at gmail dot com
23-Jul-2006 06:46
to include all type of visible chars you should try:
<?php fscanf($file_handler,"%[ -~]"); ?>
worldwideroach at hotmail dot com
14-Jul-2005 03:33
Yet another function to read a file and return a record/string by a delimiter. It is very much like fgets() with the delimiter being an additional parameter. Works great across multiple lines.
function fgetd(&$rFile, $sDelim, $iBuffer=1024) {
$sRecord = '';
while(!feof($rFile)) {
$iPos = strpos($sRecord, $sDelim);
if ($iPos === false) {
$sRecord .= fread($rFile, $iBuffer);
} else {
fseek($rFile, 0-strlen($sRecord)+$iPos+strlen($sDelim), SEEK_CUR);
return substr($sRecord, 0, $iPos);
}
}
return false;
}
rudigreen at gmail dot com
01-Jul-2005 09:43
I have a function for reading delimited files, it works for multiple lines too (i think...)
<?
//$fh - is the file pointer
//$delim - is the seperator
//$callback - self explanatory
//$len - optional
function file_read_delim($fh,$delim,$callback,$len=1024)
{
$rec = '';
while(!feof($fh))
{
$buf = fread($fh,$len);
if(strpos($buf,$delim) === false)
{
$rec .= $buf;
}
else
{
$strs = explode($delim,$buf);
foreach ($strs as $ele)
{
$rec .= $ele;
call_user_func($callback,$rec);
$rec = '';
}
}
}
}
//Here is an example how to use the function
$fh = fopen($filename,'r');
if(!$fh)
{
die 'Could not open file for reading';
}
//call the function
file_read_delim($fh,'-','cb');
fclose($fh);
function cb($rec)
{
echo "$rec \n";
}
?>
me at hesterc dot fsnet dot co dot uk
25-May-2004 01:03
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
20-Jan-2004 05:36
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 10:08
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 07:01
Clear the variables before you scan them in. As a programmer this should have been very apparent. Goof.
eugene at pro-access dot com
15-Mar-2002 05:39
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
06-Mar-2002 11:53
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|Página principal de Fanhunter.|castellano|==|0|0|0
2|fanhunter|Sección principal dedicada al universo Fanhunter.|castellano|fanhunter/|1|0|0
3|outfan|Sección principal dedicada al universo Outfan.|castellano|outfan/|1|0|0
4|fanpiro|Sección principal dedicada al universo Fanpiro.|castellano|fanpiro/|1|0|0
5|tienda|La tienda de Fanhunter.|castellano|tienda/|1|0|0
6|the zone|Sección principal Miscelánea.|castellano|thezone/|1|0|0
7|flfcn|Sección principal dedicada a Fan Letal/Fan con Nata.|castellano|fanletal/|1|0|0
8|foro|Nuestro foro de discusión.|castellano|foro/|1|0|0
9|chat|Sección para chatear.|castellano|chat/|1|0|0
10|links|Sección recopilatoria de enlaces de interés a otras páginas.|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
07-Jul-2001 06:29
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
12-Mar-2001 04:59
For C/C++ programmers.
fscanf() does not work like C/C++, because PHP's fscanf() move file pointer the next line implicitly.