call diff on two files, but ignore lines after the length of the shortest one

mindiff

#!/bin/bash

if [[ $# -lt 2 ]]; then
    echo "Usage: $0 file1 file2 [additional options to diff]"
    exit 1
fi

if1=$1
if2=$2
shift 2

trap 'rm -rf "$fifo"' EXIT
fifo=$(mktemp -d -t mindiff.XXXXXXXXX)
mkfifo "$fifo/1" "$fifo/2"

awk -vof1="$fifo/1" -vof2="$fifo/2" '
    BEGIN{ f2=ARGV[2];ARGC-- }
    ( (getline line <f2)>0 ) { print > of1; print line > of2 }
' "$if1" "$if2" &

diff "$@" "$fifo/1" "$fifo/2"

rm -rf "$fifo"