"& Gt;/dev/null 2 & gt; & amp; 1" in shell

Shell ">/dev/null 2> & 1" details shell may often see:> /dev/null 2> & 1 command results can be defined in the form of %>, where %> represents the file descriptor we will combine this command: ">/dev/null 2> & 1" is split into four parts for analysis: 1: 0> indicates stdin standard input; 1> indicates stdout standard output; 2> indicates stderr error output; 2: symbol> equivalent to 1> (default value: 1, omitted first ); therefore, ">/dev/null" is equivalent to "1>/dev/null" 3:/dev/null indicates null device file 4: <G id = "1"> </G> /dev/null 2> & 1 can also be written as "1>/dev/null 2> & 1". Then the statement execution process in the title of this article is: 1>/dev/null: first, it indicates that the standard output is redirected to an empty device file, that is, no output is made. Information to the terminal. To put it bluntly, no information is displayed. 2> & 1: Next, redirect the standard error output to the standard output. Because the standard output has been redirected to the empty device file, the standard error output is also redirected to the empty device file.