USING MIPS Simulator

Write a assembly program that repeatedly asks the user for a string and then calculates and prints out the string length. Stop the program when the string is empty (when the user hits "enter" without anything else on the line.)

Be sure to reserve enough memory in the .data for the string. Use indexed addressing to scan through the string. Strings read in with the trap handler service include a ' ' character at the end, followed by the null termination. Don't count the ' ' or the null as part of the string length.

Use the below given code and complete the assembly program:

.text

.globl main

main:

top: li $t0,0

# get string

li $v0,4 # print prompt

la $a0,prompt

syscall

li $v0,8 # code 8 == read string

la $a0,string # $a0 == address of buffer

li $a1,24 # $a1 == buffer length

syscall # Invoke the operating system.

li $t1,0 # read first character from string

lb $v0,string($t1) # $v0 = string[$t1]

beq $v0,10,exit # if character is ' ' jump to exit

# test code

# print the string

li $v0,4 # print prompt2

la $a0,prompt2 #

syscall

li $v0,4 # print body

la $a0,string #

syscall

j top

exit: li $v0,4 # print prompt2

la $a0,EndMessage #

syscall

li $v0,10 # exit

syscall

.data

prompt: .asciiz "please enter a string: "

string: .space 128

prompt2: .asciiz "the string you entered was: "

EndMessage: .asciiz "empty string entered"