how to traverse to line 5 in this makefile
#This is a test makefile for A3.It uses the files from the early version
#of the demo that we did in week 6.

main : linked_list.o main.o gcc - Wall - g - std = gnu99 -
                                                   o main linked_list.o main
                                                       .o

                                                           main.o
    : main.c linked_list.h gcc - Wall - g - std = gnu99 -
                                                  c main
                                                      .c

                                                          linked_list.o
    : linked_list.c linked_list.h gcc - Wall - g - std = gnu99 -
                                                         c linked_list.c

#notice that this target has no dependencies
                                                             clean
    : rm - f main rm - f linked_list.o rm - f main.o