Sort on shell

sort.sh

#!/usr/bin/env sh
# Prints a random line from a file
# Script by @augustohp

lines_on() {
    file=$1
    wc -l $file | awk '{print $1}'
}
random_until() {
    max=$1
    min=1
    echo $(( ($RANDOM % $max) + $min ))
}
print_line_in_file() {
    file=$1
    line=$2
    awk "NR==${line}" $file
}
if [ -z "$1" ]
then
    echo "Usage: $0 <file>"
    exit 2
fi
# Here be dragons
print_line_in_file $1 $(random_until $(lines_on $1))