this function is a great way to get integer rgb values from the html equivalent hex.
list($r, $g, $b) = sscanf('00ccff', '%2x%2x%2x');
(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
sscanf — Überträgt einen String in ein angegebenes Format
Die Funktion sscanf() ist das Eingabegegenstück zu
printf(). sscanf() liest den String
string und interpretiert ihn entsprechend dem
übergegebenen format-Parameter.
Beliebige Whitespaces im Formatstring entsprechen beliebigen Whitespaces im
Inputstring. Das heißt, dass auch ein Tabulator (\t) im
Formatstring einem einzelnen Leerzeichen des Inputstrings entsprechen kann.
stringDer zu parsende Eingabestring.
format
Das interpretierte Format für string, wie es in
der Dokumentation zu sprintf() beschrieben ist, mit
den folgenden Unterschieden:
F, g, G und
b werden nicht unterstützt.
D steht für eine Dezimalzahl.
i steht für eine Ganzzahl mit Angabe der Basis.
n steht für die Anzahl der bisher verarbeiteten Zeichen.
s beendet das Lesen beim ersten Whitespace-Zeichen.
* anstelle von argnum$
unterdrückt die Zuweisung dieser Umwandlungsspezifikation.
varsOptionale als Referenz übergebene Variablen, die die geparsten Werte enthalten.
Werden nur 2 Parameter an die Funktion übergeben, werden die analysierten Werte als Array zurückgegeben. Andernfalls, wenn optionale Parameter übergeben wurden, gibt die Funktion die Anzahl der ermittelten Werte zurück. Die optionalen Parameter müssen als Referenz übergeben werden.
Werden mehr Teilzeichenketten in format erwartet
als in string verfügbar sind, wird null
zurückgegeben.
Beispiel #1 sscanf()-Beispiel
<?php
// Ermittlung der Serien-Nr.
list($serial) = sscanf("SN/2350001", "SN/%d");
// und des Herstellungsdatums
$mandate = "Januar 01 2000";
list($monat, $tag, $jahr) = sscanf($mandate, "%s %d %d");
echo "Das Teil $serial wurde hergestellt am: "
. "$jahr-" . substr($monat, 0, 3) . "-$tag\n";
?>Werden optionale Parameter übergeben, gibt die Funktion die Anzahl der ermittelten Werte zurück.
Beispiel #2 sscanf() - Verwendung optionaler Parameter
<?php
// Auslesen der Autoren-Info und Erzeugung eines DocBook-Eintrages
$auth = "24\tLewis Carroll";
$n = sscanf($auth, "%d\t%s %s", $id, $first, $last);
echo "<author id='$id'>
<firstname>$first</firstname>
<surname>$last</surname>
</author>\n";
?>
this function is a great way to get integer rgb values from the html equivalent hex.
list($r, $g, $b) = sscanf('00ccff', '%2x%2x%2x');After playing around with this for a while, I found that if you use %[^[]] instead of %s (since php has problems with spaces when using %s) it works nicely.
For those that aren't familiar with regular expressions, %[^[]] basically matches anything that isn't nothing.
Hope this helps. - GabeFYI - if you are trying to scan from a string which contains a filename with extension. For instance:
<?php
$out = sscanf('file_name.gif', 'file_%s.%s', $fpart1, $fpart2);
?>
The scanned string in the $fpart1 parameter turns out to be 'name.gif' and $fpart2 will be NULL.
To get around this you can simply replace the "." with a space or another "white-space like" string sequence.
I didn't see any other comments on regarding string literals which contain a '.' so I thought I'd mention it. The subtle characteristics of having "white-space delimited" content I think can be a source of usage contention. Obviously, another way to go is regular expressions in this instance, but for newer users this may be helpful.
Just in case someone else spent 10 minutes of frustration like I did. This was seen on PHP Version 5.2.3-1ubuntu6.3.
Searching the bug reports shows another users misunderstanding: http://bugs.php.net/bug.php?id=7793The %[^[]]-trick may seem to work, but it doesn't!
What happens is that sscanf will simply match any characters but an opening square bracket (which is rather rare and that's why it might just seem to work).
But even worse it will expect a ]-character next and continue to match anything.
Now what you can do is make sscanf look for any character but a character that is really never used... a good choice is the linebreak "%[^\\n]", especially in combination with fscanf.
What you can also do is copy and paste any unused ascii character like #001 or something.@mikewillitsgmail.com:
<?php
$out = sscanf('file_name.gif', 'file_%[^.].%s', $fpart1, $fpart2);
echo '<pre>';
print_r($fpart1);
echo '<hr />';
print_r($fpart2);
echo '</pre>';
?>
output:
name
-
gif
The "^." part avoid the first searched string to be too greedy. But doesn't protect you against an "file_test.name.gif" input, with bad results!Security Note:
Although it is a very powerful technique, keep in mind that it is easily deceived.
Many successful exploits have been based on scanf attacks. It should not be used on untrusted input without a lot of additional validation.If you just wants filter out information between two parts of a string, i used the following, it works better for me then the sscanf function.
<?php
function scanstr($zoekstr,$part1,$part2) {
$firstpos=strpos ($zoekstr, $part1)+strlen($part1);
$lastpos=strpos ($zoekstr, $part2);
$scanresult=substr ($zoekstr, $firstpos, $lastpos-$firstpos);
return($scanresult);
}
echo scanstr ("var1=hello&var2=test&var3=more","var2=","&var3");
?>I've seen several examples of people using brackets to define what look like regexp character classes. In my limited testing I don't think they are genuine character classes but they seem to be similar.
My task was to use sscanf() to parse an array of strings with the format:
number SPACE string_which_may_also_have_spaces
The normal %s conversion command treats spaces as some kind of delimiter. So, you can get the strings if you know beforehand how many "words" there will be. But, my input was variable.
Here's what I came up with: (note use of the dollar-sign 'end of string' hidden delimiter)
sscanf($string_to_parse,'%d %[^$]s',$num,$text);
This conversion command says "look for an integer, then a space, then any string up to the end of the string"To parse a line from an Apache access log in common format:
<?php
$log = array();
$n = sscanf(trim($line), '%s %s %s [%[^]]] "%s %s %[^"]" %d %s "%[^"]" "%[^"]"',
$log['ip'],
$log['client'],
$log['user'],
$log['time'],
$log['method'],
$log['uri'],
$log['prot'],
$log['code'],
$log['bytes'],
$log['ref'],
$log['agent']
);
?>One thing to note: unlike C/C++, a variable %n is assigned to will be counted in the return value.apparently, sscanf always splits at spaces, even if spaces are not specified in the format. consider this script:
<?php
$str = "This is a\tsentence with\ttabs";
$scanned = sscanf($str, "%s\t%s\t%s");
echo join(" : ", $scanned);
?>
this echoes "This : is : a", not the expected "This is a : sentence with : tabs."
this behaviour is fine if your strings don't contain spaces, but if they do you'd be better off using explode().It should also be noted that when used with sscanf both x and X produce the same output (i.e. they are case-insensitive).
<?php
var_dump(sscanf("0xdead|0XDEAD", "%X|%x")); // worksadded country code (1) to phone number function:
function formatPhone($phone) {
if (empty($phone)) return "";
if (strlen($phone) == 7)
sscanf($phone, "%3s%4s", $prefix, $exchange);
else if (strlen($phone) == 10)
sscanf($phone, "%3s%3s%4s", $area, $prefix, $exchange);
else if (strlen($phone) > 10)
if(substr($phone,0,1)=='1') {
sscanf($phone, "%1s%3s%3s%4s", $country, $area, $prefix, $exchange);
}
else{
sscanf($phone, "%3s%3s%4s%s", $area, $prefix, $exchange, $extension);
}
else
return "unknown phone format: $phone";
$out = "";
$out .= isset($country) ? $country.' ' : '';
$out .= isset($area) ? '(' . $area . ') ' : '';
$out .= $prefix . '-' . $exchange;
$out .= isset($extension) ? ' x' . $extension : '';
return $out;
}Actually sscanf()_always_ returns an array if you specify less return variables than format specifiers. i may change this to return a scalar if only a single format specifier exists.
Note that sscanf() is (almost) the complete functional equivalent of its "C" counterpart, so you can do the following to get the expected effect :
sscanf("SN/2350001","SN/%d",&$serial)
The array return was a nicety for PHP.In PHP >= 4.3.0, if you use additional reference parameters, you will get this warning:
PHP Warning: Call-time pass-by-reference has been deprecated - argument passed by value
This clearly has the potential to cause unexpected consequences (vars left empty), and will break existing code. So don't do it! These docs need updating to say this too.
The syntax:
list($a, $b) = sscanf("hello world", "%s %s");
will work as expected, and doesn't seem to cause any problems with Apache that I've noticed.More fun with phones! This assumes that the phone number is 10 digits, with only numeric data, but it would be easy to check the length of the string first.
function formatPhone($phone) {
if (empty($phone)) return "";
sscanf($phone, "%3d%3d%4d", $area, $prefix, $exchange);
$out = @$area ? "($area) " : "";
$out .= $prefix . '-' . $exchange;
return $out;
}