Shell script for checking GPU's average usage

gpu-average-usage

#!/usr/bin/env bash

is_number() {
	[[ $1 =~ ^([0-9]+|[0-9]+\.[0-9]*|\.[0-9]+)$ ]]
}

is_integer() {
	[[ $1 =~ ^[0-9]+$ ]]
}

echo_error() {
	>&2 echo "Error: $*"
}

error() {
	echo_error "$@"
	exit 1
}

is_valid_gpu_usage_file() {
	local file_path
	file_path="$1"
	if ! [[ -r $file_path ]]; then
		echo_error $'Provided GPU path is not readable or doesn\'t exist'
		return 1
	fi

	local file_contents
	file_contents="$(< "$file_path")"
	if [[ -z $file_contents ]]; then
		echo_error 'Provided GPU file is empty'
		return 1
	fi

	if [[ $file_contents == *$'\n'* ]]; then
		echo_error "Provided GPU path doesn't yield the expected output: file must contain only 1 line"
		return 1
	fi
	if ! is_number "$file_contents"; then
		echo_error $'Provided GPU path doesn\'t yield the expected output: file must always contain a number'
		return 1
	fi
}

should_truncate=false
sampling_duration=1
samples_amount=10
gpu_usage_path=

while getopts 'td:s:g:' flag; do
	case "${flag}" in
		t) should_truncate=true ;;
		d)
			if ! is_number "$OPTARG"; then
				error "Sampling interval must be a number (float or integer)"
			fi
			sampling_duration="$OPTARG"
			;;
		s)
			if ! is_integer "$OPTARG"; then
				error "Samples amount must be an integer"
			fi
			samples_amount="$OPTARG"
			;;
		g)
			if ! is_valid_gpu_usage_file "$OPTARG"; then
				error "Invalid GPU usage file"
			fi
			gpu_usage_path="$OPTARG"
			;;
		*) error "Invalid argument: $flag"
	esac
done

if [[ -z $gpu_usage_path ]]; then
	error 'GPU usage file path is unspecified. Specify the path using the -g flag'
fi

sleep_duration="$(bc <<< "scale=4; $sampling_duration/$samples_amount")"
average="$(
	for (( i=0; i < samples_amount; i++ )); do
		echo "$(< "$gpu_usage_path")"
		sleep "$sleep_duration"
	done | awk '{sum+=$1} END {print sum/NR}'
)"

if $should_truncate; then
	average="${average%.*}"
fi

echo "$average"