распечатать реальные и эффективные идентификаторы пользователей и групп  (print real and effective user and group IDs)
  
Имя (Name)
id - print real and effective user and group IDs
Синопсис (Synopsis)
id [OPTION]... [USER]...
Описание (Description)
Print user and group information for each specified USER, or
       (when USER omitted) for the current user.
       -a     ignore, for compatibility with other versions
       -Z, --context
              print only the security context of the process
       -g, --group
              print only the effective group ID
       -G, --groups
              print all group IDs
       -n, --name
              print a name instead of a number, for -ugG
       -r, --real
              print the real ID instead of the effective ID, with -ugG
       -u, --user
              print only the effective user ID
       -z, --zero
              delimit entries with NUL characters, not whitespace;
              not permitted in default format
       --help display this help and exit
       --version
              output version information and exit
       Without any OPTION, print some useful set of identified
       information.