Bash script to log memory usage every minute for three hours

log_memory.sh

#!/bin/bash

# install bc (cli calculator):
# sudo apt-get install bc

# and make script executable: 
# chmod +x log_memory.sh

# Create or clear the usage.txt file
> memory_usage.txt

# Loop to log memory usage every minute for three hours
for i in `seq 0 180`; do
    active_kb=$(cat /proc/meminfo | grep Active: | sed 's/Active: *//g' | awk '{print $1}')
    total_kb=$(cat /proc/meminfo | grep MemTotal: | sed 's/MemTotal: *//g' | awk '{print $1}')

    active_gb=$(echo "scale=2; $active_kb / 1024 / 1024" | bc)
    total_gb=$(echo "scale=2; $total_kb / 1024 / 1024" | bc)
    
    echo "$active_gb/$total_gb GB" >> memory_usage.txt
    sleep 1m
done