A script to log cpu usage, memory usage, and temperature usage

loghw.sh

#!/bin/bash

# A script to log cpu usage, memory usage, and temperature usage

# TODO:
# 
# Log temp awk is not portable
# Validate interval
#

########## Variable Declarations ##########

append=false
output=false
interval=5

########## Function Declarations ##########

parse_options() {
    while getopts "t:ai:oh" opt; do
	case $opt in
	    t)
		type=$OPTARG
		;;
	    a)
		append=true
		;;
	    i)
		interval=$OPTARG
		if [[ 1 -ne 1  ]]; then
		    error "Invalid interval"
		fi
		;;
	    o)
		output=true
		;;
	    h)
		display_help
		exit 0
		;;
	    \?)
		display_help
		exit 1
		;;
	esac
    done
}

display_help() {

cat <<EOF

Usage: loghw -t <log_type> [options]

       -h        display help
       -i <arg>  Set interval to <arg>
       -o        Print output to stdout as well as log
       -a        Append to previous log

       The log type is either cpu, mem, or temp.

       Logging CPU usage depends on the mpstat package and
       logging the temerature depends on the lm-sensors package.

EOF

}

output() {
    if $output; then
	echo -e "$1" | tee -a $LOG_FILE
    else
	echo -e "$1" >> $LOG_FILE
    fi
}

check_if_installed() {
    dpkg -s $1 > /dev/null
    return $?
}

error() {
    echo -e "\nError: $1. Exiting.";
    display_help
    exit 1
}

########## START SCRIPT ##########

parse_options "$@"

if [[ -z "$type" ]]; then
    error "No log type supplied"
fi

HEADER="Logging started at `date` with interval $interval\n"
if [[ "$type" == "cpu" ]]; then
    installed=$(check_if_installed "sysstat")
    if [[ "$installed" -eq 1 ]]; then
	error "The package sysstat is required to log CPU usage"
    fi
    LOG_FILE=cpulog
    COMMAND="mpstat | awk '/all/ {print 100-\$12}'"
    HEADER+="AVG CPU USAGE"
elif [[ "$type" == "mem" ]]; then
    LOG_FILE=memlog
    COMMAND='free -m | awk '\''/-/ {printf "%s\t%s\n", $3, $4}'\'
    HEADER+="USED\tFREE"
elif [[ "$type" == "temp" ]]; then
    installed=$(check_if_installed "lm-sensors")
    if [[ "$installed" -eq 1 ]]; then
	error "The package lm-sensors is required to log CPU temp"
    fi
    LOG_FILE=templog
    COMMAND="sensors | awk '/temp1/ {print \$2}' | head -1"
    HEADER+="TEMP"
else
    error "Invalid log type"
fi

if ! $append; then
   :>$LOG_FILE
fi

output "$HEADER"

while true; do
    result="$(eval $COMMAND)"

    output "$result"
    sleep $interval
done