SitringStripWS versus Chr(0)

[Inf]

Hi, All!

Writing my own "winamp song to text file" script and have problem with striping ID3v1 tags.

Got ID3.au3 form >this topic, and it works great except ID3v1 tags — it returns them full 30 bytes length.

OK, it's not a problem, stripping all trailing (and leading, if any) spaces with

$Artist=StringStripWS(_ID3GetTagField("Artist"),3)
$Track=StringStripWS(_ID3GetTagField("Title"),3)
$Album=StringStripWS(_ID3GetTagField("Album"),3)

It works, but have found 1 mp3 file with ID3v1 tags, which returns trailing Ch(0) instead of Ch(32) (spaces)

(have checked it in my generated text file viewing it in hex).

And StringStripWS doesn't strips Ch(0)    (while help says "Whitespace also includes the null string ( Chr(0) ) and the standard space ( Chr(32) )").

Also checked other ID3v1-only mp3's, and they returns Ch(20), so for now the only idea I have is to ignore such *wrong* mp3's,

but I also want to know is there any solution, or did I missed something?

Edited December 22, 2013 by Inf

[l3ill]

Hi Inf,

  and welcome to the Forum!

Just a suggestion: Have you tried the 

$STR_STRIPALL (8) = strip all spaces (over-rides all other flags)
Constants are defined in StringConstants.au3

And try running it in BETA 

Other alternative would be Regexp...

Bill

Edited December 22, 2013 by l3ill

[Inf]

Hi, l3ill!

Thank you for fast reply.

I have tried flag=8 ("8 = strip all spaces (over-rides all other flags)") and it also does't strips whitespaces (Ch(0)).

Will try in BETA.

[Melba23]

Inf,

StringReplace will remove the Chr(0) characters for you:

#include <StringConstants.au3>

$sText = "ASCII" & Chr(0) & "ASCII" & Chr(0)
ConsoleWrite(StringToBinary($sText) & @CRLF)

$sStripped = StringStripWS($sText, $STR_STRIPALL)
ConsoleWrite(StringToBinary($sStripped) & @CRLF)

$sReplaced = StringReplace($sText, Chr(0), "")
ConsoleWrite(StringToBinary($sReplaced) & @CRLF)

Jon has recently altered the way some string functions deal with Chr(0) - I will take a look back at the changes and see if they have affected this function as well.

M23

[mikell]

Melba,

Chr(0) in a string provides strange results, seems 'cancel' the rest of the string

$text = "this    is " & Chr(0) & "  a   line    of   text   "
MsgBox(0, "", "="& $text &"=")

Using 3.3.8.1

[Melba23]

mikell,

That is perfectly normal as Windows regards Chr(0) as an "end-of-string" marker.

In another thread about Chr(0) Jon had this to say recently:

 

"Over time most of the AutoIt string functions have migrated to an internal string object that stores the length so that you can work with strings with nulls in them without too much trouble. Some APIs - like MsgBox - might not show the text correctly but as you've seen in this thread the nulls are usually preserved"

This is an entirely diffferent case where Chr(0) is not, contrary to the Help file statement, regarded as "whitespace". If Jon cannot amend the function without causing too many problems elsewhere, the short-term solution is to alter the Help file to remove Chr(0) from the list of characters removed by StringStripWS.

M23

[martin]

I don't know anything about _ID3GetTagField but I would expect that you need to process the return in some way before using any string functions because chr(0) is used to mark the end of an ascii string, so to me, despite what the Help says, you problem is not surprising.

[Inf]

Hi,  title="SitringStripWS versus Chr(0): post #4"> Melba23 !

Did my little investigations.

Flag=8 strips ALL spaces (even single between words, while help says "To strip single spaces between words, use the function StringReplace()").

So for now i do:

$Artist=StringStripWS(  StringReplace(_ID3GetTagField("Artist"),Chr(0)," ")  ,3)
$Track=StringStripWS(  StringReplace(_ID3GetTagField("Title"),Chr(0)," ")  ,3)
$Album=StringStripWS(  StringReplace(_ID3GetTagField("Album"),Chr(0)," ") ,3)

replacing all Ch(0) with spaces (Ch(32)) and than strip leading and trailing spaces.

Thanks to all for your time, spent helping me.

Now I'm  going for ini-file and GUI

[Inf]

I don't know anything about _ID3GetTagField but I would expect that you need to process the return in some way before using any string functions because chr(0) is used to mark the end of an ascii string, so to me, despite what the Help says, you problem is not surprising.

I'm not sure, what wrong with _ID3GetTagField, but problem in only with ID3v1, and only with some music-files.

_ID3GetTagField returns ID3v2 tags without spaces, "ready for use", ID3v1 — with.

So, only ID3v1 must be processed, and here comes problem with Ch(0).

[Melba23]

Hi,

Jon confirms it is not an quick fix so I have opened Trac ticket #2568 for the problem.

M23