Исходное сообщение
"Выпуск командной оболочки fish 2.6.0" Отправлено qwerty123, 06-Июл-17 15:15
>  "возможность доступа замещаемых команд". Это называется макроподстановка вывода. В sh $(command)    Command Substitution      Command substitution allows the output of a command to be substituted in      place of the command name itself.  Command substitution occurs when the      command is enclosed as follows:            $(command)      or the backquoted version:            `command`      The shell expands the command substitution by executing command and      replacing the command substitution with the standard output of the      command, removing sequences of one or more newlines at the end of the      substitution.