 
section .data
    str1 db "Felicia", 0ah
    len1 equ $-str1
    str2 db "lee", 0ah
    len2 equ $-str2
    msg3 db "Substring ", 0ah
    len3 equ $-msg3
    msg4 db "Not substring ", 0ah
    len4 equ $-msg4
   
section .bss
    temp resb 10
   
section .text
    global _start
   
_start:

    mov eax,4
    mov ebx,1
    mov ecx,str1
    mov edx,len1
    int 80h
   
    
   
    mov eax,4
    mov ebx,1
    mov ecx,str2
    mov edx,len2
    int 80h
   
    

;find substring
   
    mov esi, str1
    mov edi, str2
    mov ecx, esi

check_substring:
    mov bl, [edi]
    cmp bl, 0ah
    je substring
   
    mov al, [esi]
    cmp al, 0ah
    je not_substring
   
    cmp al,bl
    je update_both
    jne update_to_initial
   
update_both:
    inc esi
    inc edi
    jmp check_substring
   
update_to_initial:
    mov edi, str2
    inc ecx
    mov esi, ecx
    jmp check_substring
   
substring:
    mov eax, 4    
    mov ebx, 1
    mov ecx, msg3
    mov edx, len3
    int 80h
   
    jmp exit
   
not_substring:
    mov edx, len4  
    mov ecx, msg4  
    mov ebx, 1  
    mov eax, 4    
    int 80h
   
exit:
    mov eax,1
    mov ebx,0
    int 80h

created 1 year ago by Felicia

Assembly Online Compiler

Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.

About Assembly

Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.

Every assembler may have it's own assembly language designed for a specific computers or an operating system.

Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.

Syntax help

Assembly language usually consists of three sections,

Data section

To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section

To declare variables
text section

_start specifies the starting of this section where the actually code is written.

Variables

There are various define directives to allocate space for variables for both initialized and uninitialized data.

1. To allocate storage space to Initialized data

Syntax

variable-name    define-directive    initial-value

Define Directive	Description	Allocated Space
DB	Define Byte	1 byte
DW	Define Word	2 bytes
DD	Define Doubleword	4 bytes
DQ	Define Quadword	8 bytes
DT	Define Ten Bytes	10 bytes

2. To allocate storage space to un-initialized data

Define Directive	Description
RESB	Reserve a Byte
RESW	Reserve a Word
RESD	Reserve a Doubleword
RESQ	Reserve a Quadword
REST	Reserve a Ten Bytes

Constants

Constants can be defined using

1. equ

To define numeric constants

CONSTANT_NAME EQU regular-exp or value

2. %assign

To define numeric constants.

%assign constant_name value

3. %define

To define numeric or string constants.

%define constant_name value

Loops

Loops are used to iterate a set of statements for a specific number of times.

mov ECX,n
L1:
;<loop body>
loop L1

where n specifies the no of times loops should iterate.

Procedures

Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

procedure_name:
   ;procedure body
   ret