CODEWITHSUNDEEP
arraysstringstring-lengthhla
Jes
Jes

Reputation: 1

How to find string length in HLA?

I need help finding the string length of the user input.

sample output:

Feed Me: asdf
The String You Entered: asdf Has Length = 4

How do I do it? It's really hard to find HLA resources on the internet. The output that I got is -23 and it is supposed to be the length of the string. And if I change the pop (EBX) to pop (baseStringAddress) the result will print the ASCII decimal of the first string.

Here is my code but I don't think it's right.

program strlenFunction;
#include( "stdlib.hhf" );
#include( "cs17string.hla" );

const
nullchar: byte := 0;

static
iSize: int8:= 0; //array size
strData : byte[32];
strLength : uns16 := 31; // max number of chars
dArrayBaseAddress : dword := 0; // holds base address

procedure strlen( baseStringAddress: dword ); @nodisplay; @noframe; 
static
return: dword;
arraySize: int16;
iEBX : dword := 0; 
iEDX : dword := 0; 
iECX : dword := 0;

begin strlen;
mov(EBX, iEBX);
mov(EDX, iEDX);
mov(ECX, iECX);
pop(return);
pop(EBX);
push(return);
push(iECX);//i
push(iEDX); //counter
push(iEBX);

mov(baseStringAddress, EBX);
mov([EBX], AL);
mov(baseStringAddress, ECX);

WhileStart:
mov(0, AH);
cmp([ECX], AH);
jne WhileInc;
je EndSequence;

WhileInc: 
inc(ECX);
inc(EDX);
jmp EndSequence;

EndSequence:
stdout.puti8(AL);
pop(EDX);
pop(ECX);
pop(EBX);
ret();
end strlen;

begin strlenFunction;
stdout.put("Feed me: ");
mov(&strData, EAX);
push(EAX);
push(strLength);
call gets;

mov( @size( int8 ), AL );
mov( iSize, BL );
mul( BL );
mov( 0, EBX );
mov( AX, BX );

malloc( EBX );
mov( EAX, dArrayBaseAddress );

stdout.put("The String You Entered: ");
mov(&strData, EAX);
push(EAX);
call puts;
stdout.put(" Has Length = ");
mov(&strData, EAX);
push(EAX);
call strlen;

free( dArrayBaseAddress );

end strlenFunction;

Upvotes: 0

Views: 344

Answers (1)

Kuma
Kuma

Reputation: 467

ENVIRONMENT

  • HLA (High Level Assembler - HLABE back end, LD linker) Version 2.16 build 4409 (prototype)
  • Ubuntu 21.04

NOTE

  • HLA provides higher level capabilities which are helpful to layout and test the desired functionality before transitioning to lower level assembly concepts. The following example provides a working solution using the higher level functionality of HLA which provides a good starting point to work towards assembly.
  • Assembly code is on average less human readable than higher level languages so it is best practice to frequently use comments throughout your code.
  • HLA also allows for indentation which further improves code readability.

EXAMPLE

program Strlen;
#include("stdlib.hhf")

storage
    inputStr: string;

static 
    inputLen: int32;

begin Strlen;
    // Prompt user for input
    stdout.put("Feed me: ");

    // Flush Input
    stdin.flushInput();

    // Allocate and read input
    stdin.a_gets();

    // Save result in inputStr
    mov(EAX, inputStr);

    // Display input back to user
    stdout.put("The String You Entered: ", inputStr, nl);

    // Calculate length of input string
    str.length(inputStr);

    // Save result in inputLen
    mov(EAX, inputLen);

    // Display input length to the user
    stdout.put("Has Length = ", inputLen, nl);

    // Free allocated memory
    str.free(inputStr);
end Strlen;

Upvotes: 0

Related Questions