fds-progress

#!/bin/bash

USAGE="$0 {PID:FD}
A progress bar for a running process's position through a file.

Env vars:
INTERVAL: Modify the refresh interval.
BANNER: Alternate program for percentage display (default 'banner')
"

if [ "$#" -lt 1 ]; then
	echo "USAGE: $USAGE"
	exit 1
fi

INTERVAL=${INTERVAL:-0.5}
BANNER=${BANNER:-banner}
first=true

while [ "$first" ] || sleep "$INTERVAL"; do
	clear
	flag=
	first=

	for arg in "$@"; do
		pid=${arg%:*}
		fd=${arg#*:}

		if [ ! -d "/proc/$pid" ]; then
			echo "$pid has terminated"
			continue
		fi

		file="$(readlink -e "/proc/$pid/fd/$fd")"
		if [ ! "$file" ]; then
			echo "$pid has no readable fd $fd"
			continue
		fi

		if [ -b "$file" ]; then
			totalsize="$(blockdev --getsize64 "$file" 2>/dev/null)"
		elif [ -f "$file" ]; then
			totalsize="$(stat -c %s "$file" 2>/dev/null)"
		else
			echo "Cannot read size of $file"
			continue
		fi

		position="$(grep pos "/proc/$pid/fdinfo/$fd"| cut -f2)"
		complete=$((position * 100 / totalsize))
		echo
		echo
		echo "$file"
		echo
		$BANNER "$complete%"
		flag=true
	done

	[ ! "$flag" ] && break
done

echo "All readable processes complete, or no more files could have their size determined."