Why is quotemeta needed or why do you have to call 'system' this way? For quotemeta the code will work for files with special characters in them. For system I imagine the LIST version exists to make it easier to pass in a large number of parameters, deal with ones with special characters, and/or build a list of parameters without having to join them later on. As explained by others the IO redirection ('>') is something the shell handles but when system is called in LIST context it will be passed to the tar command as a parameter instead. Because tar has no '>' command line option it errors out -- just like it does with any other incorrect parameter (e.g. -y).