Как к ftp как корень?

В дополнение к корректным ответам, уже данным: Если Вы выполняете удар и хотите узнать то, что "команда" как CD - Вы, может использовать тип

$ type cd
cd is a shell builtin

или почему нет:

$ type time
time is a shell keyword

в то время как, например, время гну обычно уже включено в Ваше любимое распределение:

$ which time
/usr/bin/time

Okey okey Вы получаете идею, затем какого черта тип?

$ type type
type is a shell builtin

Вот отрывок руководства удара:

       type [-aftpP] name [name ...]
          With no options, indicate how each name would be interpreted  if  used  as  a
          command name.  If the -t option is used, type prints a string which is one of
          alias, keyword, function, builtin,  or  file  if  name  is  an  alias,  shell
          reserved word, function, builtin, or disk file, respectively.  If the name is
          not found, then nothing is printed, and an exit status of false is  returned.
          If  the -p option is used, type either returns the name of the disk file that
          would be executed if name were specified as a command  name,  or  nothing  if
          ‘‘type  -t  name’’ would not return file.  The -P option forces a PATH search
          for each name, even if ‘‘type -t name’’ would not return file.  If a  command
          is  hashed,  -p  and -P print the hashed value, not necessarily the file that
          appears first in PATH.  If the -a option is used,  type  prints  all  of  the
          places  that  contain  an  executable  named name.  This includes aliases and
          functions, if and only if the -p option is  not  also  used.   The  table  of
          hashed  commands  is  not  consulted when using -a.  The -f option suppresses
          shell function lookup, as with the command builtin.  type returns true if any
          of the arguments are found, false if none are found.