The document summarizes a course project to create a countdown clock shell script. A team of 3 students - Md. Ashikur Rahman, Yousuf Mia, and Mizanur Rahman Masum - created a shell script that takes a time in seconds as a command line argument. It displays a countdown from that time, printing the seconds remaining each second until it reaches zero and displays "Times Up". The script checks for the required argument, sets the start time and time remaining variables, and uses a while loop and sleep to continuously decrement and display the countdown until finished.

1. Operating System Lab
Course Code: CSE 324
CourseTeacher: Mr. Md. Sabab Zulfiker
Project Name: Count Down Clock in Shell Script

2. Team Name: Gladiators
Md. Ashikur Rahman
191-15-2469
Yousuf Mia
191-15-2360
Mizanur Rahman Masum
191-15-2502

3. Introduction ofTime Count Down

4. Project Source Code:
#!/bin/bash
if [ $# -lt 1 ]
then
echo "Time Needed in Seconds"
echo "Usage: $0 <seconds>"
echo "Example: $0 10"
exit 1
fi
time="$1"
start="$SECONDS"
s=1
function main(){
echo "Welcome..."
while [ $s -gt 0 ]
do
s="$((time - (SECONDS - start)))"
echo -ne "r r"
echo -ne "r$s seconds left"
sleep 1
done
echo -e "nTimes Up"
exit 0
}
main