cp-progress

#!/bin/bash

USAGE="$0 (PID|{ARGS})
A progress bar for a running cp process.
The process may be given by PID or by any number of ARGS as understood by pgrep(1).
'pgrep ARGS' should match the process name (including arguments) uniquely.

When copying multiple files, each is treated as a seperate copy,
ie. only progress through the current file is given.

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

if [ "$#" -lt 1 ]; then
	echo "USAGE: $0 [--dir] PID"
	exit 1
fi

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

if [ "$1" == "--dir" ]; then
	FROM_FD=4
	TO_FD=5
	shift 1
else
	FROM_FD=3
	TO_FD=4
fi

if grep -Eq "^ *[0-9]+ *$" <<<"$1"; then
	# Is numeric
	PID="$1"
else
	PID="$(pgrep "$@")"
	if [ "$(wc -l <<<"$PID")" -ne 1 ]; then
		echo "Bad process specification."
		exit 1
	fi
fi

while sleep "$INTERVAL"; do
	if ! [ -d "/proc/$PID" ]; then
		clear
		echo "Process complete."
		exit 0
	fi

	fromfile="$(readlink "/proc/$1/fd/$FROM_FD")"
	if [ ! "$fromfile" ]; then continue; fi
	if [ "$fromfile" != "$oldfile" ]; then
		totalsize="$(stat -c %s "$fromfile")"
	fi
	oldfile="$fromfile"
	position="$(grep pos "/proc/$1/fdinfo/$TO_FD"| cut -f2)"
	complete=$(python3 -c "print('%.2f' % ($position * 100. / $totalsize))")
	clear
	echo
	echo "Copying $fromfile"
	echo
	$BANNER "$complete%"
done