Data stream redirection in linux

Linux data stream redirection & gt;: overwrite all the data to the specified file or device. 1 & gt ;: output "correct data" to the specified file or device in a overwriting method 1 & gt ;: output "correct data" to the specified file or device in an accumulative way. 2 & gt ;... linux data stream redirection>: overwrite all the data to the specified file or device. 1>: output "correct data" to the specified file or device in a overwriting method. 1 >>: output "correct data" to the specified file or device in an accumulative way. 2>: output "wrong data" to the specified file or device by overwriting method 2>: output "wrong data" to the specified file or device in an accumulative way <: replace the Data originally required by the keyboard with the file content <: it indicates the ending input character. for example, "I want to use cat to directly output the input information to the catfile, and when the keyboard inputs eof, this input ends 』, then I can do this: [plain] [r Oot @ www ~] # Cat> catfile <"eof"> This is a test.> OK now stop> eof <= enter this keyword. it will end immediately without entering [ctrl] + d [root @ www ~]. # Cat catfile This is a test. OK now stop where eof can be replaced by any other string.