& On the issue I would like to ask the following : What is the difference between the two orders #command "2>&1 & out.file # Command "out.file 2>&1 & On the issue 2>&1 means strerr Methods Redirected to strout "Out.file is equivalent to 1>out.file, strout redirect to file out.file "Command" out.file 2>&1 "is equivalent to" command 2>&1 "out.file" or "command 2>&1 1>out.file" Maybe when & is used as command line argument, the entire command will run at backgroud. u get hae Yi immediately after you execute command shell prompt # 1. In short Command, "out.file 2>&1 Run command, and direct possible strout and strerr to file out.file Command, "2>&1 & out.file . . . , And run it at backgroud. & On the issue Shell in the process of creating one, with three Wenjianmiaoshufu : 0,1,2, and the standards corresponding to process input, standard output, standard error document. & On the issue [ Closed window ]