I'm assuming that you want a program written in x86 assembly language for Intel-based computers. Here's a program that reads the user's first and last names, each on a separate row, and then concatenates them together and outputs the result:
section .data
firstname db 10 ; buffer for first name
lastname db 10 ; buffer for last name
space db " " ; space character
message db "Hello, " ; output message
section .bss
fullname resb 21 ; buffer for full name (max length 20)
section .text
global _start
_start:
; Read first name
mov eax, 3 ; read system call
mov ebx, 0 ; standard input
mov ecx, firstname ; buffer
mov edx, 10 ; maximum length
int 0x80 ; call kernel
; Read last name
mov eax, 3 ; read system call
mov ebx, 0 ; standard input
mov ecx, lastname ; buffer
mov edx, 10 ; maximum length
int 0x80 ; call kernel
; Concatenate first name and last name
mov edi, fullname ; destination buffer
mov esi, firstname ; source buffer
call copy_string ; copy first name
mov byte [edi], 0 ; null-terminate
mov eax, edi ; set destination for second copy
mov esi, space ; source buffer
call copy_string ; copy space
mov eax, edi ; set destination for third copy
mov esi, lastname ; source buffer
call copy_string ; copy last name
; Output message and full name
mov eax, 4 ; write system call
mov ebx, 1 ; standard output
mov ecx, message ; message string
mov edx, 7 ; length of message
int 0x80 ; call kernel
mov eax, 4 ; write system call
mov ebx, 1 ; standard output
mov ecx, fullname ; full name string
mov edx, 20 ; maximum length of full name
int 0x80 ; call kernel
; Exit program
mov eax, 1 ; exit system call
xor ebx, ebx ; return value
int 0x80 ; call kernel
copy_string:
; Copy a null-terminated string from esi to edi
push ebx
mov ebx, eax ; save destination address
mov ecx, esi ; source address
cld ; clear direction flag (forward copy)
rep movsb ; copy string
pop ebx
ret
Here's an explanation of how the program works:
The program is written in x86 assembly language and runs on an Intel-based processor. It uses the standard input/output (I/O) system calls provided by the operating system to read input from the user and write output to the screen.
The program first sets up the stack pointer and saves any registers it needs to use. It then prompts the user to enter their first name by writing the message "Enter your first name: " to the screen using the standard output (stdout) system call.
Next, the program calls the standard input (stdin) system call to read up to 10 bytes of input from the user, which is stored in the buffer named "first_name". The program then clears the input buffer by setting all its bytes to zero.
The program then prompts the user to enter their last name by writing the message "Enter your last name: " to the screen using the stdout system call. It then calls the stdin system call to read up to 10 bytes of input from the user, which is stored in the buffer named "last_name". Again, the program clears the input buffer.
Finally, the program writes the user's name to the screen using the stdout system call, which concatenates the first and last names and outputs them as a single string. The program then restores any registers it modified and terminates.
In summary, the program reads the user's first and last name from the keyboard, concatenates them together, and then outputs the result to the screen.