Another comment already mentioned that there is presently no way to provide arguments to a command. That was the first thing I was looking for, myself. It did not even support the syntax Capistrano promotes by using an underscore, such as my_dir.ls_la, and that's a shame.
Of course, we could use #system to invoke a Bourne shell to run any command, but that's too much overhead for heavy use, so that option does not matter.
One of the most important things a shell does is piping. Rush does allow one to get away from needing to pipe through commands like grep, wc, awk, and sed, but you cannot get away from the fact that there are cases where you just have to pipe data between commands that have a complex relationship with that data that you would not want to recreate within Rush. For Rush to have a chance of being considered seriously, it also needs to address pipes and make them easy to invoke.
Another comment already mentioned that there is presently no way to provide arguments to a command. That was the first thing I was looking for, myself. It did not even support the syntax Capistrano promotes by using an underscore, such as my_dir.ls_la, and that's a shame.
Of course, we could use #system to invoke a Bourne shell to run any command, but that's too much overhead for heavy use, so that option does not matter.
One of the most important things a shell does is piping. Rush does allow one to get away from needing to pipe through commands like grep, wc, awk, and sed, but you cannot get away from the fact that there are cases where you just have to pipe data between commands that have a complex relationship with that data that you would not want to recreate within Rush. For Rush to have a chance of being considered seriously, it also needs to address pipes and make them easy to invoke.