Discussion: Some String functions

// 
// String Library functions for LSL. 
// Nothing incredibly clever but functions I have found useful.
// free to use and abuse yto your hearts content.
//
string Characters = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~"; 
string Letters= "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 
string Numbers = "0123456789"; 


integer STRINVALID = -99999; 
integer STREQUAL = 0; 
integer STRLESSTHAN = -1; 
integer STRGREATERTHAN = 1; 


integer OnlyContains(string a, string b) 
{ 
    integer len = llStringLength(a); 
    integer result = FALSE; 
    if(len != 0) 
    { 
        result = TRUE; 
        integer index = 0; 
        do 
        { 
            string chara = llGetSubString(a,index,index); 
            integer posa = llSubStringIndex(b,chara); 
              
            if(posa < 0) 
            { 
                result = FALSE; 
                index = len; 
            } 
            ++index; 
                  
        } 
        while(index < len); 
    } 
    return result; 
} 


integer IsNumeric(string a) 
{ 
   return OnlyContains(a,Numbers);
} 

integer IsAlpha(string a) 
{ 
   return OnlyContains(a,Letters);
} 

integer IsAlphanumeric(string a) 
{ 
   return OnlyContains(a,Letters + Numbers);
} 


integer strncmp(string a, string b,integer len) 
{ 
    // compares two strings character by character. 
    // return as soon as there is a difference 
    integer result = STREQUAL; 
    if(a != b) 
    { 
        integer index = 0; 
        do 
        { 
            string chara = llGetSubString(a,index,index); 
            string charb = llGetSubString(b,index,index); 
             
            integer posa = llSubStringIndex(Characters ,chara); 
            integer posb = llSubStringIndex(Characters ,charb); 
             
            if((posa >= 0) && (posb >= 0)) 
            { 
                result = posa - posb; 
            } 
            else if(posa >= 0) 
            { 
                result = STRGREATERTHAN; 
            } 
            else if(posb >= 0) 
            { 
                result = STRLESSTHAN; 
            } 
             
            if(result != STREQUAL) index = len; 
            ++index; 
                 
        } 
        while(index < len); 
    } 
     
    // limit to constant values 
    if(result < STRLESSTHAN)result = STRLESSTHAN; 
    else if(result > STRGREATERTHAN)result = STRGREATERTHAN; 
         
    return result; 
} 

integer strnicmp(string a, string b,integer len) 
{ 
    string lca = llToLower(a); 
    string lcb = llToLower(b); 
    return strncmp(lca,lcb,len); 
} 

integer strcmp(string a, string b) 
{ 
    integer lena = llStringLength(a); 
    integer lenb = llStringLength(b); 
    integer result = STRINVALID; 
    if(lena < lenb) 
        result =  strncmp(a,b,lena); 
    else 
        result =  strncmp(a,b,lenb); 
     
    return result; 
} 


integer stricmp(string a, string b) 
{ 
    integer lena = llStringLength(a); 
    integer lenb = llStringLength(b); 
    string lca = llToLower(a); 
    string lcb = llToLower(b); 
    integer result = STRINVALID; 
    if(lena < lenb) 
        result =  strncmp(lca,lcb,lena); 
    else 
        result =  strncmp(lca,lcb,lenb); 
     
    return result; 
} 

// Some test uses
default 
{ 
    state_entry() 
    { 
        string a = "ABCDEF[]"; 
        string b = "abcdef[]"; 
        string c = "hello";
        string d = "1234";
        integer result = strcmp(a,b); 
        integer result2 = strncmp(a,b,3); 
        integer result3 = stricmp(a,b); 
        integer result4 = strnicmp(a,b,4); 
        integer result5 = IsNumeric(c);
        integer result6 = IsAlpha(c);
        integer result7 = IsAlphanumeric(c);
        integer result8 = IsNumeric(d);
        integer result9 = IsAlpha(d);
        integer result10 = IsAlphanumeric(d);
        llOwnerSay("result =  " + (string)result); 
        llOwnerSay("result2 =  " + (string)result2); 
        llOwnerSay("result3 =  " + (string)result3); 
        llOwnerSay("result4 =  " + (string)result4); 
        llOwnerSay("result5 =  " + (string)result5); 
        llOwnerSay("result6 =  " + (string)result6); 
        llOwnerSay("result7 =  " + (string)result7); 
        llOwnerSay("result8 =  " + (string)result8); 
        llOwnerSay("result9 =  " + (string)result9); 
        llOwnerSay("result10 =  " + (string)result10); 
    } 
} 

integer strncmp(string a, string b,integer len)
{
    return llDeleteSubString(a,len, 0x10000000) != llDeleteSubString(b,len, 0x10000000);
}

integer strnicmp(string a, string b,integer len)
{
	return llToLower(llDeleteSubString(a,len, 0x10000000)) != llToLower(llDeleteSubString(b,len, 0x10000000));
}

integer strcmp(string a, string b)
{
	return a != b;
}

integer stricmp(string a, string b)
{
    return llToLower(a) != llToLower(b);
}