Difference between revisions of "LlStringTrim"

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|func_footnote
|func_footnote
|func_desc
|func_desc
|return_text=that is '''src''' with leading and/or trailing white space (spaces, tabs, and line feeds) trimmed from it.
|return_text=that is {{LSLP|src}} with leading and/or trailing white space (spaces, tabs, and line feeds) trimmed from it.
|spec
|spec
|caveats
|caveats
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{{!}}}
{{!}}}
|examples=
|examples=
Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it:
Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it:
 
<syntaxhighlight lang="lsl2">llStringTrim("User input", STRING_TRIM);</syntaxhighlight>
llStringTrim("User input", STRING_TRIM);  
 


This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function).
This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function).
<lsl>
<syntaxhighlight lang="lsl2">
default
default
{
{
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         llListen(4, "", llGetOwner(), "");
         llListen(4, "", llGetOwner(), "");
     }
     }
     on_rez(integer a)
 
     on_rez(integer start_param)
     {
     {
         llResetScript();
         llResetScript();
     }
     }
     listen(integer chan, string name, key id, string msg)
 
     listen(integer channel, string name, key id, string message)
     {       
     {       
         //track the length
         //track the length
         integer length = llStringLength(msg);
         integer length = llStringLength(message);
          
          
         //trim msg (not necessary to store these to variables but makes reading easier)
         //trim message (not necessary to store these to variables but makes reading easier)
         string trim_left  = llStringTrim(msg, STRING_TRIM_HEAD);
         string trim_left  = llStringTrim(message, STRING_TRIM_HEAD);
         string trim_right = llStringTrim(msg, STRING_TRIM_TAIL);
         string trim_right = llStringTrim(message, STRING_TRIM_TAIL);
         string trim_both  = llStringTrim(msg, STRING_TRIM);
         string trim_both  = llStringTrim(message, STRING_TRIM);


         //output the results
         //output the results
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     }
     }
}
}
</lsl>
</syntaxhighlight>
|helpers
|helpers
|also_functions
|also_functions
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|history=
|history=
*Introduced in 1.13.4
*Introduced in 1.13.4
Date of release [[ Release_Notes/Second_Life_Release/1.15#Release_Notes_for_Second_Life_1.15.0.282.29_April_25.2C_2007 | 25-04-2007 ]]
|notes=
|notes=
Aside from white space at the beginning and / or end, the actual string will be unaffected. This means too, though, that extraneous spaces within the string -- for instance, a mistaken double-space type -- will not be corrected.  
*The exact set of characters stripped are 0x09 (tab), line feed (0x0a, "\n"), vertical tab (0x0b), form feed (0x0c), carriage return (0x0d) and space (0x20, " ").
** Only line feed and space function as true whitespace within SL, the others will produce some manner of a printable character.
** The "\t" escape code doesn't actually represent the tab character, but several spaces instead.
** Other whitespace characters defined in Unicode, such as non-breaking space (0xa0) or specific-width spaces in the 0x2000 range are not stripped.
* Aside from white space at the beginning and / or end, the actual string will be unaffected. This means too, though, that extraneous spaces within the string -- for instance, a mistaken double-space type -- will not be corrected.  
* The following will remove all double spaces and leading and trailing spaces.
<syntaxhighlight lang="lsl2">llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory</syntaxhighlight>


The following will remove all double spaces and leading and trailing spaces.
* This method strips spaces from the sentence and may use less memory
<lsl>llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory</lsl>
<syntaxhighlight lang="lsl2">
 
This method does the same thing but may use less memory
<lsl>
//Added By To-mos Codewarrior
//Added By To-mos Codewarrior
string str1 = "some words to remove the spaces from";
string str1 = "some words to remove the spaces from";
integer index;
integer index;
while(~index=llSubStringIndex(str1," "))
while(~index=llSubStringIndex(str1," ")) {
data=llDeleteSubString(str1,index,index);
    data=llDeleteSubString(str1,index,index);
</lsl>
}
</syntaxhighlight>
* The following will do the same:
<syntaxhighlight lang="lsl2">(string)llParseString2List(src, [" "], []); //works but can use a large quantity of memory</syntaxhighlight>
 
* [[llList2Json]] also trims strings contained in the list. Thus, an easy way to trim an entire list of strings is:
<syntaxhighlight lang="lsl2">
list l = ["  a  ", " b", "c ", " d "];
list trimmedList = llJson2List(llList2Json(JSON_ARRAY, l));
</syntaxhighlight>
 
* Finally, [[llReplaceSubString]] is probably the easiest way to trim spaces from a string:
<syntaxhighlight lang="lsl2">llReplaceSubString("some words to remove the spaces from", " ", "", 0);</syntaxhighlight>
|deprecated
|deprecated
|cat1=String
|cat1=String

Latest revision as of 13:04, 21 May 2024

Summary

Function: string llStringTrim( string src, integer type );

Returns a string that is src with leading and/or trailing white space (spaces, tabs, and line feeds) trimmed from it.

• string src
• integer type – STRING_TRIM* flag(s)

Constant Description
STRING_TRIM_HEAD 0x1 Trims white space off the beginning.
STRING_TRIM_TAIL 0x2 Trims white space off the end.
STRING_TRIM 0x3 Trims white space off the beginning and end.

Examples

Whenever you are accepting unstructured input from a user -- whether via chat or via a notecard -- it is a good idea to always full trim it: 

llStringTrim("User input", STRING_TRIM);

This example returns the number of leading and trailing 'white space' characters on a string that were removed (not particularly useful but shows how to use the function). 

default
{
    state_entry()
    {
        llListen(4, "", llGetOwner(), "");
    }

    on_rez(integer start_param)
    {
        llResetScript();
    }

    listen(integer channel, string name, key id, string message)
    {       
        //track the length
        integer length = llStringLength(message);
        
        //trim message (not necessary to store these to variables but makes reading easier)
        string trim_left  = llStringTrim(message, STRING_TRIM_HEAD);
        string trim_right = llStringTrim(message, STRING_TRIM_TAIL);
        string trim_both  = llStringTrim(message, STRING_TRIM);

        //output the results
        llOwnerSay("Initial length  = " + (string)length +
                 "\nLeading Spaces  = " + (string)(length - llStringLength(trim_left))+
                 "\nTrailing Spaces = " + (string)(length - llStringLength(trim_right))+
                 "\nTrimmed Message = \"" + trim_both + "\"");
    }
}

Notes

  • The exact set of characters stripped are 0x09 (tab), line feed (0x0a, "\n"), vertical tab (0x0b), form feed (0x0c), carriage return (0x0d) and space (0x20, " ").
    • Only line feed and space function as true whitespace within SL, the others will produce some manner of a printable character.
    • The "\t" escape code doesn't actually represent the tab character, but several spaces instead.
    • Other whitespace characters defined in Unicode, such as non-breaking space (0xa0) or specific-width spaces in the 0x2000 range are not stripped.
  • Aside from white space at the beginning and / or end, the actual string will be unaffected. This means too, though, that extraneous spaces within the string -- for instance, a mistaken double-space type -- will not be corrected.
  • The following will remove all double spaces and leading and trailing spaces.
llDumpList2String(llParseString2List(src, [" "], []), " "); //works but can use a large quantity of memory
  • This method strips spaces from the sentence and may use less memory
//Added By To-mos Codewarrior
string str1 = "some words to remove the spaces from";
integer index;
while(~index=llSubStringIndex(str1," ")) {
    data=llDeleteSubString(str1,index,index);
}
  • The following will do the same:
(string)llParseString2List(src, [" "], []); //works but can use a large quantity of memory
  • llList2Json also trims strings contained in the list. Thus, an easy way to trim an entire list of strings is:
list l = ["  a  ", " b", "c ", " d "];
list trimmedList = llJson2List(llList2Json(JSON_ARRAY, l));

llReplaceSubString("some words to remove the spaces from", " ", "", 0);

Deep Notes

History

  • Introduced in 1.13.4
Date of release 25-04-2007

Search JIRA for related Issues

Signature

function string llStringTrim( string src, integer type );
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