#!/bin/bash

if [ $# -ne 2 ]; then
	echo "usage : ./<nom_programme> <operation> <valeur>"
	exit 1
fi

if [ $1 = "sel" ]; then
	cut -d' ' -f$2 ventes.dat
	echo "nb de lignes : "
	cut -d' ' -f$2 ventes.dat | wc -l 
elif [ $1 = "som" ]; then
	total=0
	ligne=`grep $2 ventes.dat | cut -d' ' -f2:6`
	for i in $ligne
	do
		total=$(($total+i))
	done
	echo $2 " -> total: " $total
else
	echo "opération invalide"
fi