wondering if i could apply loading while it performs, is this possible? - linux

Question

I am new to bash, aware that only one line is executed at a time. have a script i feel comfortable with. works fine, but i would like to add a loading sign at the top of the script based on the amount of the script that has run. Now this seems much more complex like some python scripting. but is it possible to do this in a bash script?
This would be extremely helpful as i tend to repeat usages of code through out other scripts. Im slow and i need reminders so i make scripts to automate all the tasks i need to do that involve remembering lines of commands.
Also i would be happy to take any suggestions or ideas to add into the code.
#!/bin/bash
BOLDY='\033[1;1;33m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m'
printf " ${GREEN} by MONEY ${CN}"
echo ''
printf " ${BOLDY} T H E M A C F L I P P E R${CN}"
echo ''
printf " ${YELLOW}starting mac address change for WLAN0 and ETH0${NC}\n"
echo ' ........................................................'
sleep 3
printf ${GREEN}
service NetworkManager stop
ifconfig wlan0 down
ifconfig wlan0 up
service NetworkManager start
printf " ${YELLOW} STARTING MAC CHANGER ${CN}\n"
printf " ${GREEN} -- ${CN}\n"
sleep 1
printf " ${GREEN} -- \n"
macchanger -s eth0
sleep 1
printf " ${GREEN} -- \n"
ifconfig eth0 down
macchanger -r eth0
sleep 1
printf " ${GREEN} -- \n"
ifconfig eth0 down
macchanger -s eth0
ifconfig eth0 up
ip link set eth0 up
printf " ${GREEN} -- \n"
sleep 1
printf "${YELLOW}ethernet MAC changed${NC}\n"
echo ''
printf ${GREEN}
macchanger -s eth0
sleep 6
printf "${YELLOW}starting wlan0 MAC change${NC}\n"
printf ${GREEN}
ifconfig wlan0 down
macchanger -s wlan0
sleep 1
macchanger -r wlan0
sleep 1
macchanger -s wlan0
ifconfig wlan0 up
ip link set wlan0 up
printf "${YELLOW}Wireless lan MAC changed${NC}\n"
echo ''
printf ${GREEN}
macchanger -s wlan0
sleep 6
clear
printf "${YELLOW}Wlan0 and Eth0 MAC addresses have been changed\n"
printf "${YELLOW}exiting program${NC}"
sleep 4
clear
exit
want to add some loading script near the top obviously this is related to time and not a specific instance in the script occurring, but for now it serves as an example.
echo LOADING
{
for pc in $(seq 1 100); do
echo -ne "$pc%\033[0k\r"
sleep 1
done
echo
}
exit

Answer 1

You could have this progress bar function:
#!/bin/sh
progbar()
{
command "$#" > /dev/null 2>&1 &
PID=$!
printf "["
# While process is running...
while kill -0 $PID 2> /dev/null; do
printf "▓"
sleep 1
done
printf "]"
}
Then call it with progbar some_long_running_command.
This will increase the size of a great progress bar like this:
[▓▓▓▓▓▓▓▓▓
Also, for this to work, all the running period of your process must be in one single call as an argument to progbar.
So, you should enclose your whole process to a function, namely long_function and then run progbar long_function.