# Reading mp3 Tag

**URL:** <https://www.ruby-forum.com/t/reading-mp3-tag/167598>\
**Category:** Ruby\
**Created:** [May 10, 2009, 12:00am UTC](https://www.ruby-forum.com/t/reading-mp3-tag/167598 "2009-05-10T00:00:34Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![catsquotl](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/f9ae1b/32.png) [@catsquotl](https://www.ruby-forum.com/u/catsquotl)\
**Post date:** [May 10, 2009, 12:00am UTC](https://www.ruby-forum.com/t/reading-mp3-tag/167598/1 "2009-05-10T00:00:34Z")

</div>

Hi,  
I am taking a free course on Ruby and encountered a behavior i don`t  
understand…

## this code produces jibberish on standard output

f1 = File.open(“song.mp3”,‘r’)  
tag = f1.read[-128…-1]

## puts tag.dump

produces  
“]o\254\fM\301s\245\256\264\365\211r\201\251U\334’\016\325\340\274q\341\311\222\312\025M\222\210\234v0V\002M^\324\226W\023mQ\311\037\242\305(XT\353\236w\372\023c\275\254\241\267\277\374\306cd\036\356\204\026}?Z\016\003\275\016L\311j\217{h\242\016\253+\326vQ\305J\235\351\372)L\222HI%$\333/_Q\303\274\220\247Td\000)\342\026\024\035_\364\220\027\253\021\312E\341;”

## This code however produces proper output. Can someone explain why the first code doesn`t work for the TAG and the seccond does???

f1 = File.open(“song.mp3”,‘r’)  
id3 = f1.read[0…300]  
tag = f1.read[-128…-1]

## puts id3.dump puts ‘-------------------’ puts tag.dump

## produces “ID3\003\000\000\000\000#vCOMM\000\000\000#\000\000\000eng\000#100%-Free-MP3s(Dalnet) Annie TRCK\000\000\000\003\000\000\00013TYER\000\000\000\005\000\000\0002000PRIV\000\000\000’\000\000WM/MediaClassPrimaryID\000\274}`\321#\343\342K\206\241H\244\*(D\036PRIV\000\000\000)\000\000WM/MediaClassSecondaryID\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000PRIV\000\000\000\037\000\000WM/WMContentID\000FX;n\231\201HD\206kL\234\>\306Z\350TPUB\000\000\000\023\000\000\000Music For PleasureTCON\000\000\000\005\000\000\000(24)TALB\000\000\000\027\000\000\000(SUMMER HOLIDAY 1963)”

“TAGDancing  
Shoes\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000Cliff  
Richard and The Shadows\000(SUMMER HOLIDAY  
1963)\000\000\000\000\000\000\000\0002000#100%-Free-MP3s(Dalnet)  
Anni\000\r\030”

Catsquotl

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<div class="post-metadata">

**Author:** ![catsquotl](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/f9ae1b/32.png) [@catsquotl](https://www.ruby-forum.com/u/catsquotl)\
**Post date:** [May 10, 2009, 4:48am UTC](https://www.ruby-forum.com/t/reading-mp3-tag/167598/2 "2009-05-10T04:48:27Z")

</div>

Hi,

2009/5/10 Catsquotl [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid):

> * * *
> 
> ## HOLIDAY 1963)"
> 
> “TAGDancing  
> Shoes\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000Cliff  
> Richard and The Shadows\000(SUMMER HOLIDAY  
> 1963)\000\000\000\000\000\000\000\0002000#100%-Free-MP3s(Dalnet)  
> Anni\000\r\030”

I guess you are using Ruby on Windows and the song.mp3 contains  
“0x1a”(end of file marker).  
Try File.open(“song.mp3”,‘rb’) instead of File.open(“song.mp3”,‘r’)

Regards,  
Park H.

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<div class="post-metadata">

**Author:** ![catsquotl](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/f9ae1b/32.png) [@catsquotl](https://www.ruby-forum.com/u/catsquotl)\
**Post date:** [May 11, 2009, 10:35am UTC](https://www.ruby-forum.com/t/reading-mp3-tag/167598/3 "2009-05-11T10:35:58Z")

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Heesob P. schreef:

> > 
> 
> I guess you are using Ruby on Windows and the song.mp3 contains  
> “0x1a”(end of file marker).  
> Try File.open(“song.mp3”,‘rb’) instead of File.open(“song.mp3”,‘r’)
> 
> Regards,  
> Park H.

That worked thanks.  
I did see the b flag in the IO documentation. Just didn`t find the right  
way to use it…  
I still am puzzeled though why in my first example the Tagline did get  
read if i first read the first 100 characters…

Eelco