Why does xls2csv convert text to transliteration?

Question

PHP

We have a certain price list in xls, which is taken from a third-party server, unpacked by the cabextract utility, and converted to csv using xls2csv. In the unpacked xls the text is written in Russian. At the output in csv, the text written in Cyrillic is translated into transliteration. I did not find anything similar to transliteration encodings in the xls2csv settings.
What could be the problem?
Additionally: the server is on centos, a php script is launched by cron, which downloads, unpacks the archive via system(cabextract.... ) and converts to csv via system(xls2csv... )

Answer 1

A small addition.
If the script is run by cron, such garbage with transliteration appears.
If you run the script from the console with the hands "php readxls.php" - everything is fine.

Answer 2

exec ("LANG=ru_RU.UTF-8; xls2csv .....") tried?