I'm using vs.file.regmatch to check if a value exists in a file. The file is one line. If the permissions on the file don't allow zabbix to read the file it generates a permission denied error which moves the trigger to unsupported. Even adding preprocessing to force the value to zero if the result is not in the range 0-1 doesn't fix the issue. Is there a way to test whether a file can be read before the regmatch?