# $2 = include special characters; 1 = yes, 0 = no; defaults to yes
function randstring()
{
+ local len="${1:-16}"
+
[ "$2" == "0" ] && CHAR="[:alnum:]" || CHAR="[:graph:]"
- cat /dev/urandom 2>/dev/null | tr -cd "$CHAR" 2>/dev/null | head -c ${1:-16} 2>/dev/null
+ # /dev/urandom isn't guaranteed to generate valid multi-byte characters.
+ # Specifying the C locale eliminates the "Illegal byte sequence" error
+ # that 'tr' outputs in such cases.
+ LC_CTYPE=C tr -cd "$CHAR" < /dev/urandom 2>/dev/null | head -c "$len" 2>/dev/null
echo
}