Write in MIPS ASSEMBLY :

$($plz note that enames.dat only contains the names and nothing more$)$

Description:

Write a program that implements a linked list to store element names from a periodic table file

"enames.dat". The program will then print the names in the periodic table constructed. The output

MUST be in the order the elements were read in from the file, eg$.1$st element printed first.

All nodes of the link list and string are to be allocated on the heap.

Nodes are to be added to the head of the list.

The input file must be declared in main with the label ptfname in a single line as:

ptfname: $.$ascitiz "path$/$enames$.$dat"

where path is the full path to enames.dat,

eg$.$ Windows: c:$/$Users$/$name$/$Desktop$/$cs$2640/$pt

Mac$0$s: $/$Users$/$name$/$desktop$/$cs$2640/$pt

address getnode $($address data, address next$)$: returns an address to a new node

initialized with data and next

void traverse $($address list, address proc$)$ : traverses the list and calls proc passing

the data of the node visit, MUST use recursion to traverse from the last node to the first node.

main:

open and read lines from the file enames.dat

creates a link list of these lines head, the lines are to be created using strdup

call traverse$($head$,$ print$)$ to output the lines $-$ this must output the names in the order read in

void print $($cstring source$)$ : output source to the console using format: #$ where $ is the

string and # is the length of the string.

Procedures needed from the last project: strdup, strlen, malloc

Procedure open, close, fgetln are given in the file fileio.s

Required I$/$O:

# is the number of elements read from the file, the number before the element name is the length of

the name. F$.$ Last is your name.

Hints:

head: $.$word $0$

input: space $80$

main:

open file enames.dat $($open$)$

dol

get a line of input from the file $($fgetln$)$

if no characters read from the file $($return value from fgetln is $0)$

break

$s=$ strdup$($input$)$

head $=$ getnode$($s$,$ head$)$

I while $($true$)$

close file $($close$)$

traverse$($head$,$ print$)$

return

node$-$address getnode$($cstring s$,$ address list$)$

allocate node $($malloc$)$

node.data $=s$

node.next $=$ list

return node

void print$($cstring $s)$

output s $($syscall $4)$

void traverse$($address list, address proc$)--$recursive

if $($list $!=0)1$

traverse$($list$.$next$)$

proc$($list$.$data$)--$jalr instruction

r

Damuirant $\frac{1}{?}.$

CONTENT OF FILEIO.S:

# fileio.s $-$ file i$/$o library

# void fgetln $($int fd$,$ cstring buf$)-$ get a line of text from a file into buf, full path

# $*$no$*$ buffer overflow check

# $($

included, null terminated$)$

# parameters

# a$0$: fd $($file descriptor$)$

# a$1$: buf

# return:

# v$0$: number of characters read, $-1->$error, $0->$eof

#

$.$globl fgetln

fgetln: move $t$0,$ $a$1$ # save a$1$

li $a$2,1$ # $1$ byte at a time

$\_$do: li $v$0,14$

syscall

blez $v$0,\_$eof # eof or error

lb $t$1,($$a$1)$

addiu $a$1,$ $a$1,1$

bne $t$1,\text{'}$

$\text{'},\_$do

$\_$eof: sub $v$0,$ $a$1,$ $t$0$ # number of characters read

beqz $v$0,\_$endif

sb $zero, $($$a$1)$ # null byte

$\_$endif: move $a$1,$ $t$0$ # restore a$1$

jr $ra

# int fd $=$ open$($cstring filename, int mode$)$

#

# parameter:

# a$0$: file name

# a$1$: $0->$rdonly, $1->$wronly, $2->$rdwr

# return:

# v$0$: fd $($file descriptor$),-1$ if error

#

$.$globl open

open: li $v$0,13$

syscall

jr $ra

# void fclose$($int fd$)-$ close file

#

# parameter:

# a$0$: fd

#

$.$globl close

close:

li $v$0,16$

syscall

jr $ra