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The redirections are part of the setup for running a command. > and < tie the STDOUT and STDIN streams to a file. This processing is handled by the shell, not the program being executed, so they are not considered part of the programs argument list. Since this is pre-execution setup work as well, the redirection happens before the program is executed, thus happen even if the program execution fails. So, given the command line: zcho It is cold today! > winter.txt The shell would Parse the line into it's components Argument list: ['zcho', 'It', 'is', 'cold', 'today!'] Redirections: STDOUT -> winter.txt Setup STDIN, STDOUT, and STDERR STDIN: tied to the shell's current STDIN stream STDOUT: tied to a new stream created by opening winter.txt for writing (with truncation) STDERR: tied to the shell's current STDERR stream. Extract the first argument and use it as the program/command name (zcho) Attempt to execute the program/command with the arguments given You can confirm the redirection happens first by running your invalid command with STDERR redirection: kicken@web1:~$ zcho It is cold today! 2> error.txt kicken@web1:~$ cat error.txt -bash: zcho: command not found The error message from the zcho command is redirected to the error.txt file rather than displayed in the terminal.