# truncate a giving file, all contents of the file are be clearedif(`SELECT 'x$file' = 'x'`){--echoPleaseassignafilenameto$file!!exit;}letTRUNCATE_FILE=$file;perl;useEnv;Env::import('TRUNCATE_FILE');openFILE,'>',$TRUNCATE_FILE||die"Can not open file $file";closeFILE;EOF