我想使用Unix Shellscript模拟CPU调度算法，但是执行Shell脚本时代码不起作用。大部分代码是从C转换而来的，由于C的结构与bash有所不同，因此我不知道如何解决该代码。这是代码：
sjf()
{
#Variables and arrays
declare -a processesSJF=("${!1}")
declare -a arrivalsSJF=("${!2}")
declare -a burstsSJF=("${!3}")
numberOfProcesses="${#processesSJF[@]}" #declare how many processes are there
next=1 #Fix for sorting via burst. This stores the index.
#Sorted already by arrival time. Now, it is time to sort via burst/execution. Arrival time <= Execution time
for ((i=0; i<$numberOfProcesses; i++))
do
totalBurstTime=$(($totalBurstTime + ${burstsSJF[i]}))
minimumBurst=${burstsSJF[$next]} #variable redirection again to the value of next
for ((j=next; j<$numberOfProcesses; j++))
do
if (($totalBurstTime >= ${arrivalsSJF[j]} && ${burstsSJF[j]} < $minimumBurst))
then
tempProcess=${processesSJF[$next]}
${processesSJF[$next]}=${processesSJF[j]}
${processesSJF[j]}=$tempProcess
tempArrival=${arrivalsSJF[$next]}
${arrivalsSJF[$next]}=${arrivalsSJF[j]}
${arrivalsSJF[j]}=$tempArrival
tempBurst=${burstsSJF[$next]}
${burstsSJF[$next]}=${burstsSJF[j]}
${burstsSJF[j]}=$tempBurst
fi
done
next=$(($next+=1))
done
#Ordering done. Now it is ordered, I can call on FCFS' calcs.
#The completion time for all processes
for ((i=0; i<$numberOfProcesses; i++)) #for loop from https://www.cyberciti.biz/faq/bash-for-loop/
do
sumOfBurstTimeSJF=$(($sumOfBurstTimeSJF + ${burstsSJF[i]})) #Adds bursts up to that point.
completion_timeSJF[i]=$sumOfBurstTimeSJF #Defines completion time for that process,
done
#Turnaround time and waiting time
for ((i=0; i<$numberOfProcesses; i++))
do
turnaround_timeSJF[i]=$((${completion_timeSJF[i]} - ${arrivalsSJF[i]}))
total_turnaroundSJF=$(($total_turnaroundSJF + ${turnaround_timeSJF[i]}))
waiting_timeSJF[i]=$((${turnaround_timeSJF[i]} - ${burstsSJF[i]}))
total_waitSJF=$(($total_waitSJF + ${waiting_timeSJF[i]}))
done
#To-do: Ordering and gantt chart
#Printing of table
#printf doc:https://www.computerhope.com/unix/uprintf.htm
printf "Program Name\t Arrival Time\t Burst Time\t Completion Time\t Turnaround Time\t Waiting Time\t\n\n"
for ((i=0; i<$numberOfProcesses; i++))
do
printf " %s\t\t\t %s\t %s\t %s\t %s\t %s\t\n\n" "${processesSJF[i]}" "${arrivalsSJF[i]}" "${burstsSJF[i]}" "${completion_timeSJF[i]}" "${turnaround_timeSJF[i]}" "${waiting_timeSJF[i]}"
done
printf "Average waiting time: %s\n" "$(($total_waitSJF / $numberOfProcesses))"
printf "Average turnaround time: %s\n" "$(($total_turnaroundSJF / $numberOfProcesses))"
}
round_robin()
{
#Variables and arrays
declare -a processesRR=("${!1}")
declare -a arrivalsRR=("${!2}")
declare -a burstsRR=("${!3}")
time_quantum="${!4}" #Redirection again needed so $4 won't just print out tquantum
numberOfProcesses="${#processesRR[@]}" #declare how many processes are there
numberOfProcessesRunning=$numberOfProcesses #for keeping track on which processes have finished.
#Time remaining assignment
for ((i=0; i<$numberOfProcesses; i++))
do
remaining_time[i]=${burstsRR[i]}
done
printf "Program Name\t Arrival Time\t Burst Time\t Completion Time\t Turnaround Time\t Waiting Time\t\n\n"
#Actual algorithm. This also generates the table.
complete=0 #For checking the completion of a process
time=0 #For checking time
i=0 #Index
resetPrinciple=$(($numberOfProcesses - 1)) #Fix to test operation not allowing arithmetic
while [[ $numberOfProcessesRunning != 0 ]]
do
if (( ${remaining_time[i]} <= $time_quantum && ${remaining_time[i]} > 0 )) #indicates process completes here.
then
((time += ${remaining_time[i]}))
remaining_time[i]=0
complete=1
elif (( ${remaining_time[i]} > 0 )) #process was not completed
then
((${remaining_time[i]} - $time_quantum))
((time += ${remaining_time[i]}))
fi
if (( ${remaining_time[i]} == 0 && $complete == 1 ))
then
numberOfProcessesRunning=$(($numberOfProcessesRunning - 1))
completion_timeRR[i]=$time
turnaround_timeRR[i]=$(($time - ${arrivalsRR[i]}))
waiting_timeRR[i]=$((${turnaround_timeRR[i]} - ${burstsRR[i]}))
total_turnaroundRR=$(($total_turnaroundRR + ${turnaround_timeRR[i]}))
total_waitingRR=$(($total_waitingRR + ${waiting_timeRR[i]}))
complete=0 #start again anew
printf " %s\t %s\t %s\t %s\t %s\t %s\t\n\n" "${processesRR[i]}" "${arrivalsRR[i]}" "${burstsRR[i]}" "${completion_timeRR[i]}" "${turnaround_timeRR[i]}" "${waiting_timeRR[i]}"
fi
if (( $i == $resetPrinciple )) #to avoid non-existent entries and let it reset
then
i=0
elif (( ${arrivalsRR[i]} <= $time )) #check time if we can increment
then
((i++))
else #¯\_(ツ)_/¯
i=0
fi
done
avrWaitTime=$(($total_waitingRR / $numberOfProcesses))
avrTurnTime=$(($total_turnaroundRR / $numberOfProcesses))
printf "Average waiting time: %s\n" "$avrWaitTime"
printf "Average turnaround time: %s\n" "$avrTurnTime"
}
# based on http://blockofcodes.blogspot.com/2015/08/first-come-first-serve-scheduling.html
# print Gantt chart
printf "\n" # Empty line
printf " GANTT CHART \n"
printf " *********** \n"
# print top bar
printf "\n"
for((i=0; i<$numberOfProcesses; i++))
do
for((j=0; j<"${burstsFCFS[i]}"; j++))
do
printf -- "--" #this fixes the argument error - Gabs
printf ""
done
done
printf "\n|"
# printing process id in the middle
for((i=0; i<$numberOfProcesses; i++))
do
for((j=0; j<${burstsFCFS[i]} - 1; j++))
do
#printf "\n"
printf ${processesFCFS[i]}
done
for((j=0; j<${burstsFCFS[i]} - 1; j++))
do
printf " "
printf "|"
done
done
printf "\n "
# printing bottom bar
for((i=0; i<$numberOfProcesses; i++))
do
for((j=0; j<${burstsFCFS[i]} - 1; j++))
do
printf -- "--"
printf ""
done
done
printf "\n"
# printing the time line
printf "0"
for((i=0; i<$numberOfProcesses; i++))
do
turnaround_time[i]=$((${completion_time[i]} - ${arrivalsFCFS[i]}))
for((j=0; j<${burstsFCFS[i]}; j++))
do
printf " "
if [[ ${turnaround_time[i]} > ${turnaround_time[$((j + 1))]} ]]
then
printf "\b" # backspace : remove 1 space
printf "%d " "${turnaround_time[i]}"
fi
done
done
printf "\n"
甘特图的输出如下所示：
GANTT CHART
***********
-------------------------------------------------- -------------------
| Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1Proc1 | | | | | | | | | | | | | | | | | | | | | | | | ProcessProcessProcessProcess | | | | P2P2 | |
-------------------------------------------------- ----------
0 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 25 30 30 30 32 32