fscanf

(PHP 4 >= 4.0.1, PHP 5)

fscanfAnalizza l'input da un file secondo un determinato formato

Descrizione

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

La funzione fscanf() è simile a sscanf(), ma prende il proprio input da un file associato con handle e interpreta l'input in accordo con il parametro format, che viene descritto nella documentazione della funzione sprintf(). Se vengono passati solo due parametri a questa funzione, i valori esaminati verranno restituiti in un vettore. Altrimenti, se vengono passati i parametri opzionali, la funzione restituirà il numero dei valori assegnati. I parametri opzionali devono essere passati da reference.

Ogni spazio nella stringa di formato identifica uno spazio nel flusso di input. Questo significa che anche i tab \t presenti nella stringa di formato possono identiicare uno spazio nel flusso di input.

Example #1 Esempio di fscanf()

<?php
$handle 
fopen("users.txt""r");
while (
$userinfo fscanf ($handle"%s\t%s\t%s\n")) {
    list (
$name$profession$countrycode) = $userinfo;
    
//... fai quacosa coi valori ...
}
fclose($handle);
?>

Example #2 Cntyennts of users.txt

javier  argonaut        pe
hiroshi sculptor        jp
robert  slacker us
luigi   florist it

Nota: Nelle versioni di PHP precedenti alla 4.3.0, il numero massimo di caratteri letti da un file era di 512 (o fino al primo \n, dipende da quale si incontra prima). Dal PHP 4.3.0 si possono esaminare linee di lunghezza arbitraria.

Vedere anche fread(), fgets(), fgetss(), sscanf(), printf() e sprintf().

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User Contributed Notes 9 notes

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1
nico at nicoswd dot com
7 months ago
If you want to parse a cron file, you may use this pattern:

<?php

while ($cron = fscanf($fp, "%s %s %s %s %s %[^\n]s"))
{

}

?>
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1
arentzen at religion dot dk
6 years ago
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()
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1
worldwideroach at hotmail dot com
8 years ago
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;
}
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1
eugene at pro-access dot com
12 years ago
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.
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0
Bertrand dot Lecun at prism dot uvsq dot Fr
6 years ago
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.
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0
loco.xxx at gmail dot com
7 years ago
to include all type of visible chars you should try:

<?php fscanf($file_handler,"%[ -~]"); ?>
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0
robert at NOSPAM dot NOSPAM
11 years ago
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.
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0
james at zephyr-works dot com
12 years ago
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.
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yasuo_ohgaki at hotmail dot com
13 years ago
For C/C++ programmers.

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