Will someone propose me a solution ?
if it is a bug , Avast should fix it
"avast" is a double-wrapper around avastcmd-derived scanner, not directly an executable application.
the "flaw" was a consequence of $* expansion in its wrapper script, the app itself is OK.
change the last line of the script (/usr/lib/avast4workstation/bin/wrapper-script.sh) from:
$AVAST_PREFIX/bin/$programname $*
to
$AVAST_PREFIX/bin/$programname "$@"
thanks for the report, pupusse!
regards,
PC