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How to use nasm and ld to write assembly code!
skiscratcher (3)

Source: https://www.tutorialspoint.com/assembly_programming/assembly_basic_syntax.htm
Step 1:
Create a new bash repl. We will be using a bash script to automate assembling, linking, and running, although normally that would be a job for make.
Step 2: Create a new file called main.asm.
Step 3: In order to test, we'll put a simple hello world program in. If you want to learn about how this works, check the link above. Here's the code:

section	.text
   global _start     ;must be declared for linker (ld)
   mov	edx,len     
   mov	ecx,msg     
   mov	ebx,1       
   mov	eax,4      
   int	0x80       
   mov	eax,1      
   int	0x80     

section	.data
msg db 'Hello, world!', 0xa  
len equ $ - msg     

Step 4: Now let's add the assembler to our script.
Add this to the bash script:
nasm -f elf -o main.o main.asm
If you've ever used gcc, the -o option might be familiar to you. It's for determining output. Put the main.asm wherever you like, it's the input. Don't put it after the -f or -o, though.
Step 5: Let's pass our file through the linker and run it!
Add this to your bash script:
ld -m elf_i386 -s -o main main.o
Like nasm, -o means output and you can put the main.o wherever, except after -o and -m. Make sure that the input to ld is the output from nasm. In order to run it, type ./PATH/TO/main, in this case ./main.
If it says Hello World, you're good to go!