using
xls2csv -x /usr/share/nginx/html/price_list_EN.xls -s cp1252 -d 8859-1 > /usr/share/nginx/html/price_list_EN.csv
in linux commandline it works and exports it correctly, but if I use it on php
$transf2 = "xls2csv -x /usr/share/nginx/html/price_list_EN.xls -s cp1252 -d 8859-1 > /usr/share/nginx/html/price_list_EN.csv";
exec($transf2);
a file named price_list_EN.csv appears but it remains empty...