Difference between revisions of "LlStringLength"

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m (Replaced old <LSL> block with <source lang="lsl2">)
(*To quickly find out the number of bytes (in UTF-8), you can use llStringToBase64 (see also snippet there))
 
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|func_footnote
|func_footnote
|func_desc
|func_desc
|return_text=that is the number of characters in '''str''' (not counting the null).
|return_text=that is the number of characters in '''str'''.
|spec
|spec
|caveats=
|caveats=
*The index of the last character is not equal to the string length.
*The index of the last character is not equal to the string length.
**Character indexs start at zero (the index of the first character is zero).
**Character indexs start at zero (the index of the first character is zero).
*llStringLength() gets the number of characters, not bytes
**LSL-2 sees all strings as UTF-8
**LSL-Mono sees all string as UTF-16
**Both UTF-8 and UTF-16 use multibyte characters
*Some communication functions (e.g. llHTTPResponse) are limited by number of Bytes, and work with UTF-8 strings
**To quickly find out the number of bytes (in UTF-8), you can use [[llStringToBase64]] (see also snippet there)
|constants
|constants
|examples=
|examples=
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</source>
</source>
<hr>
*LSL-2 sees all strings as UTF8
*LSL-Mono sees all string as UTF16
*llStringLength gets the number of characters
*Both UTF8 and UTF16 use multibyte characters
*Some communication functions (e.g. llHTTPResponse) are limited by number of Bytes, and work with UTF8 strings
<source lang="lsl2">
integer getStringBytes(string msg) {
    //Definitions:
    //msg == unescapable_chars + escapable_chars
    //bytes == unescapable_bytes + escapable_bytes
    //unescapable_bytes == unescapable_chars
    //s == unescapable_chars + (escapable_bytes * 3)
    string s = llEscapeURL(msg);//uses 3 characters per byte escaped.
   
    //remove 1 char from each escapable_byte's triplet.
    //t == unescapable_chars + (escapable_bytes * 2)
    string t = (string)llParseString2List(s,["%"],[]);
   
    //return == (unescapable_chars * 2 + escapable_bytes * 4) - (unescapable_chars + (escapable_bytes * 3))
    //return == unescapable_chars + escapable_bytes == unescapable_bytes + escapable_bytes
    //return == bytes
    return llStringLength(t) * 2 - llStringLength(s);
}
</source>
*Getting string bytes including multibyte characters
:If we write bytes of msg and s as:
::mb(msg bytes) = nb(no escaped bytes) + bb(before escaped bytes)
::sb(s bytes) = nb + ab(after escaped bytes)
:And,
::ab = bb * 3 (each 1 byte like '#' becomes escaped to 3 bytes "%23"):
:Then,
::mb = sb - bb * 2
:All escaped in s are now "%xx"(x:0-9 or A-F) forms, so, bb = number of '%'s in s.
:To count '%'s, we make string t removing '%'s from s, and:
::bb = sb - tb(t bytes)
:(We separate s to a list removing '%'s by llParseString2List(), and again join to one string t by typecast.)
:Now we got answer:
::mb = sb - (sb - tb) * 2 = tb * 2 - sb
*Refer Blog(Japanese)
:http://snumaw.blogspot.jp/2009/01/lsl-lldialog.html
:http://jinko.slmame.com/e602732.html


|helpers
|helpers

Latest revision as of 06:13, 24 January 2024

Summary

Function: integer llStringLength( string str );

Returns an integer that is the number of characters in str.

• string str

Caveats

  • The index of the last character is not equal to the string length.
    • Character indexs start at zero (the index of the first character is zero).
  • llStringLength() gets the number of characters, not bytes
    • LSL-2 sees all strings as UTF-8
    • LSL-Mono sees all string as UTF-16
    • Both UTF-8 and UTF-16 use multibyte characters
  • Some communication functions (e.g. llHTTPResponse) are limited by number of Bytes, and work with UTF-8 strings
    • To quickly find out the number of bytes (in UTF-8), you can use llStringToBase64 (see also snippet there)
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Examples

// assumptions: 
//    object name: LSLWiki
//    script name: _lslwiki

default
{
    state_entry()
    {
        string HowLongAmI = "123";
        integer strlen = llStringLength(HowLongAmI);
        llOwnerSay( "'" + HowLongAmI + "' has " +(string) strlen + " characters.");
        // The owner of object LSLWiki will hear 
        // LSLWiki: '123' has 3 characters.
    }
}

See Also

Functions

•  llGetListLength

Deep Notes

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Signature

function integer llStringLength( string str );
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