octdec

(PHP 4, PHP 5)

octdec — 8 進数を 10 進数に変換する

説明

number octdec ( string $octal_string )

octal_string により指定された 8 進数を 10 進数表現した数値を返します。

パラメータ

octal_string: 変換したい 8 進文字列。

返り値

octal_string を 8 進で表した値を返します。

変更履歴

バージョン	説明
4.1.0 以降	この関数は、integer 型の範囲をこえる大きな数値も変換できるようになりました。そのような値は、float で返します。

例

例1 octdec() の例


<?php
echo octdec('77') . "\n";
echo octdec(decoct(45));
?>

上の例の出力は以下となります。

63
45

参考

decoct() - 10 進数を 8 進数に変換する
bindec() - 2 進数を 10 進数に変換する
hexdec() - 16 進数を 10 進数に変換する
base_convert() - 数値の基数を任意に変換する

mt_srand

[edit] Last updated: Fri, 25 May 2012

add a note User Contributed Notes octdec

cubbo at quakenet dot php 18-Feb-2009 05:49


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);



?>

contato at andersonfraga dot net 18-Aug-2008 01:30


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 03:03


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 01:51


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 25-Oct-2001 08:03


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

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