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PHP - Manual: imap_utf7_decode

2024-12-22

imap_utf7_decode

(PHP 4, PHP 5, PHP 7, PHP 8)

imap_utf7_decodeDecodes a modified UTF-7 encoded string

说明

imap_utf7_decode(string $string): string|false

Decodes modified UTF-7 string into ISO-8859-1 string.

This function is needed to decode mailbox names that contain certain characters which are not in range of printable ASCII characters.

参数

string

A modified UTF-7 encoding string, as defined in » RFC 2060, section 5.1.3.

返回值

Returns a string that is encoded in ISO-8859-1 and consists of the same sequence of characters in string, or false if string contains invalid modified UTF-7 sequence or string contains a character that is not part of ISO-8859-1 character set.

参见

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User Contributed Notes 4 notes

up
9
Anonymous
7 years ago
I can't find method for converting imap utf7 into utf8.
So I have to write several lines of code to solve this issue. May be this could be usefull. Here is no error handling but it could be added.

Usage:
$imap_utf7 = '[Gmail]/&BBIEMAQ2BD0EPgQ1-';
$utf8 =  ImapUtf7::decode($imap_utf7);
$imap_utf7_2 =  ImapUtf7::encode($utf8);

[ImapUtf7.php]
<?php
class ImapUtf7 {
    static
$imap_base64 =
       
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,';
    static private function
encode_b64imap($s) {   
       
$a=0; $al=0; $res=''; $n=strlen($s);
        for(
$i=0;$i<$n;$i++) {
           
$a=($a<<8)|ord($s[$i]); $al+=8;
            for(;
$al>=6;$al-=6) $res.=self::$imap_base64[($a>>($al-6))&0x3F];
        }
        if (
$al>0) { $res.=self::$imap_base64[($a<<(6-$al))&0x3F]; }
        return
$res;
    }
    static private function
encode_utf8_char($w) {
        if (
$w&0x80000000) return '';
        if (
$w&0xFC000000) $n=5; else
        if (
$w&0xFFE00000) $n=4; else
        if (
$w&0xFFFF0000) $n=3; else
        if (
$w&0xFFFFF800) $n=2; else
        if (
$w&0xFFFFFF80) $n=1; else return chr($w);
       
$res=chr(( (255<<(7-$n)) | ($w>>($n*6)) )&255);
        while(--
$n>=0) $res.=chr((($w>>($n*6))&0x3F)|0x80);
        return
$res;
    }
    static private function
decode_b64imap($s) {
       
$a=0; $al=0; $res=''; $n=strlen($s);
        for(
$i=0;$i<$n;$i++) {
           
$k=strpos(self::$imap_base64,$s[$i]); if ($k===FALSE) continue;
           
$a=($a<<6)|$k; $al+=6;
            if (
$al>=8) { $res.=chr(($a>>($al-8))&255);$al-=8; }
        }
       
$r2=''; $n=strlen($res);
        for(
$i=0;$i<$n;$i++) {
           
$c=ord($res[$i]); $i++;
            if (
$i<$n) $c=($c<<8) | ord($res[$i]);
           
$r2.=self::encode_utf8_char($c);
        }
        return
$r2;
    }
    static function
encode($s) {
       
$n=strlen($s);$err=0;$buf='';$res='';
        for(
$i=0;$i<$n;) {
           
$x=ord($s[$i++]);
            if ((
$x&0x80)==0x00) { $r=$x;$w=0; }
            else if ((
$x&0xE0)==0xC0) { $w=1; $r=$x &0x1F; }
            else if ((
$x&0xF0)==0xE0) { $w=2; $r=$x &0x0F; }
            else if ((
$x&0xF8)==0xF0) { $w=3; $r=$x &0x07; }
            else if ((
$x&0xFC)==0xF8) { $w=4; $r=$x &0x03; }
            else if ((
$x&0xFE)==0xFC) { $w=5; $r=$x &0x01; }
            else if ((
$x&0xC0)==0x80) { $w=0; $r=-1; $err++; }
            else {
$w=0;$r=-2;$err++; }
            for(
$k=0;$k<$w && $i<$n; $k++) {
               
$x=ord($s[$i++]); if ($x&0xE0!=0x80) { $err++; }
               
$r=($r<<6)|($x&0x3F);
            }
            if (
$r<0x20 || $r>0x7E ) {
               
$buf.=chr(($r>>8)&0xFF); $buf.=chr($r&0xFF);
            } else {
                if (
strlen($buf)) {
                   
$res.='&'.self::encode_b64imap($buf).'-';
                   
$buf='';
                }
                if (
$r==0x26) { $res.='&-'; } else $res.=chr($r);
            }
        }
        if (
strlen($buf)) $res.='&'.self::encode_b64imap($buf).'-';
        return
$res;
    }
    static function
decode($s) {
       
$res=''; $n=strlen($s); $h=0;
        while(
$h<$n) {
           
$t=strpos($s,'&',$h); if ($t===false) $t=$n;
           
$res.=substr($s,$h,$t-$h); $h=$t+1; if ($h>=$n) break;
           
$t=strpos($s,'-',$h); if ($t===false) $t=$n;
           
$k=$t-$h;
            if (
$k==0) $res.='&';
            else
$res.=self::decode_b64imap(substr($s,$h,$k));
           
$h=$t+1;
        }
        return
$res;
    }
}
up
4
Anonymous
19 years ago
For "Outlook-style" UTF-7, you can also use:

mb_convert_encoding( $str, "ISO_8859-1", "UTF7-IMAP" ); # for decoding
mb_convert_encoding( $str, "UTF7-IMAP", "ISO_8859-1" ); # for encoding
up
3
Min He
12 years ago
For Chinese charset, we can use:

mb_convert_encoding($mailbox, "UTF7-IMAP", "GB2312");

when you want to create a mailbox in Chinese.

OR

mb_convert_encoding($mailbox, "GB2312", "UTF7-IMAP");

when you want to show the listed mailbox with the right charset.
up
-1
sven at planb dot de
21 years ago
imap_utf7_decode decodes 'modified'.
For decoding Outlook UTF-7 - texts I use --enable-recode and $latin1string=recode_string("UTF-7..ISO_8859-1",$utf7string);
Don't use recode-3.5c.*rpm from Contrib.
recode_string seems to be buggy.

官方地址:https://www.php.net/manual/en/function.imap-utf7-decode.php

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