[7m simple-command [0;0m

Commands are composed of words.  The first word may by the name of a shell
builtin, an Oil proc / shell "function", an external command, or an alias:

    echo hi               # a shell builtin doesn't start a process
    ls /usr/bin ~/src     # starts a new process
    myproc "hello $name"
    myshellfunc "hello $name"
    myalias -l


Redirects are also allowed in any part of the command:

    echo 'to stderr' >&2
    echo >&2 'to stderr'

    echo 'to file' > out.txt
    echo > out.txt 'to file'
