mt_srand
Hi, this is an attempt to explain octdec().
There is one bug, if input is not octal, it doesn't return a proper decimal.
<?php
$octal = (int) "764";
function octal_to_decimal($int)
{
$data = integer;
$i = (strlen($int) - 1);
$parse_int = str_split($int);
foreach($parse_int as $value)
{
$data += (int)($value * pow(8, $i));
$i--;
}
return $data;
}
/**
* explanation of the PHP function octdec()
*/
print octal_to_decimal($octal) . "<br />";
/**
* the PHP function octdec()
*/
print octdec($octal);
?>
octdec
(PHP 4, PHP 5)
octdec — Conversion d'octal en décimal
Description
Retourne une chaîne contenant la représentation décimale du nombre octal_tring .
Valeurs de retour
La représentation décimale de octal_string
Historique
| Version | Description |
|---|---|
| Depuis la version 4.1.0 | Cette fonction peut également convertir de très grands nombres. Elle retourne un nombre de type float dans ce cas. |
Exemples
Exemple #1 Exemple avec octdec()
<?php
echo octdec('77') . "\n";
echo octdec(decoct(45));
?>
L'exemple ci-dessus va afficher :
63 45
Voir aussi
- decoct() - Convertit de décimal en octal
- bindec() - Convertit de binaire en décimal
- hexdec() - Convertit de hexadécimal en décimal
- base_convert() - Convertit un nombre entre des bases arbitraires
add a note
User Contributed Notesoctdec
cubbo at quakenet dot php
18-Feb-2009 02:49
18-Feb-2009 02:49
contato at andersonfraga dot net
18-Aug-2008 10:30
18-Aug-2008 10:30
Number is octal?
Simple and easy:
<?php
function is_octal($x) {
return decoct(octdec($x)) == $x;
}
echo is_octal(077); // true
echo is_octal(195); // false
?>
Thanks
[]'s
harry at disgruntledgoat dot com
27-Mar-2007 01:03
27-Mar-2007 01:03
Calling the sticky bit "text" is not erroneous: On UNIX back in 1974, it instructed the operating system to retain the text segment of the program in swap space after the process exited. This speeded subsequent executions by allowing the kernel to make a single operation of moving the program from swap to real memory.
11-Sep-2002 10:51
The 'S' flag for Unix file access rights is badly computed in the above sample.
If the corresponding 'x' bit (exec) is not set, and the 's' bit (setgid/setuid/sticky) is set, then the flag should not be displayed as and uppercase 'S', but as a lower case 's'. Also the sticky bit (mainly used for folders with public right access rights such as /tmp to protect against deletion by non owner) is badly named ("text"?).
meheler at searchbc dot com
26-Oct-2001 05:03
26-Oct-2001 05:03
This function and decoct work great when working with file permissions. For example:
<?php
$mode = octdec('4750');
$user['suid'] = ($mode & 04000);
$user['read'] = ($mode & 00400);
$user['write'] = ($mode & 00200);
$user['execute'] = ($mode & 00100);
$group['sgid'] = ($mode & 02000);
$group['read'] = ($mode & 00040);
$group['write'] = ($mode & 00020);
$group['execute'] = ($mode & 00010);
$other['text'] = ($mode & 01000);
$other['read'] = ($mode & 00004);
$other['write'] = ($mode & 00002);
$other['execute'] = ($mode & 00001);
$attrs = array('-','-','-','-','-','-','-','-','-','-');
if ($system['dir']) $attrs[0] = 'd';
if ($user['read']) $attrs[1] = 'r';
if ($user['write']) $attrs[2] = 'w';
if ($user['execute']) $attrs[3] = 'x';
if ($user['suid']) $attrs[3] = 'S';
if ($group['read']) $attrs[4] = 'r';
if ($group['write']) $attrs[5] = 'w';
if ($group['execute']) $attrs[6] = 'x';
if ($group['sgid']) $attrs[6] = 'S';
if ($other['read']) $attrs[7] = 'r';
if ($other['write']) $attrs[8] = 'w';
if ($other['execute']) $attrs[9] = 'x';
if ($other['text']) $attrs[9] = 'T';
echo '<pre>';
echo 'Mode Decimal: ' . $mode . "\n";
echo 'Mode Octal: ' . decoct($mode) . "\n";
echo 'Mode String: ' . implode('',$attrs)."\n";
echo '</pre>';
?>
Outputs:
Mode Decimal: 2536
Mode Octal: 4750
Mode String: -rwSr-x---
-Mike