linuxベースコマンドその:suとsudoユーザー切替コマンドの使用

[root@localhost babyfish]# su --h
Usage: su [OPTION]... [-] [USER [ARG]...]
Change the effective user id and group id to that of USER.
  -, -l, --login               make the shell a login shell,
                               clears all envvars except for TERM,
                               initializes HOME, SHELL, USER, LOGNAME and PATH #     ，         ，  HOME,SHELL,USER,logname；  ，    PATH  
  -c, --command=COMMAND        pass a single COMMAND to the shell with -c #         ，        
  --session-command=COMMAND    pass a single COMMAND to the shell with -c
                               and do not create a new session
  -f, --fast                   pass -f to the shell (for csh or tcsh) #   csh tsch， shell         
  -m, --preserve-environment   do not reset HOME, SHELL, USER, LOGNAME
                               environment variables #     ，        
  -p                           same as -m
  -s, --shell=SHELL            run SHELL if /etc/shells allows it  #      shell
      --help     display this help and exit #    
      --version  output version information and exit #      
A mere - implies -l.   If USER not given, assume root.
Report su bugs to [email protected]
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
For complete documentation, run: info coreutils 'su invocation'

[root@localhost babyfish]# sudo -h
sudo - execute a command as another user
usage: sudo [-D level] -h | -K | -k | -V
usage: sudo -v [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid]
usage: sudo -l[l] [-AknS] [-D level] [-g groupname|#gid] [-p prompt] [-U user name] [-u user name|#uid] [-g groupname|#gid] [command]
usage: sudo [-AbEHknPS] [-r role] [-t type] [-C fd] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid] [-g groupname|#gid] [VAR=value] [-i|-s] [<command>]
usage: sudo -e [-AknS] [-r role] [-t type] [-C fd] [-D level] [-g groupname|#gid] [-p prompt] [-u user name|#uid] file ...
Options:
  -a type       use specified BSD authentication type
  -b            run command in the background
  -C fd         close all file descriptors >= fd
  -E            preserve user environment when executing command
  -e            edit files instead of running a command
  -g group      execute command as the specified group
  -H            set HOME variable to target user's home dir.
  -h            display help message and exit
  -i [command]  run a login shell as target user
  -K            remove timestamp file completely
  -k            invalidate timestamp file
  -l[l] command list user's available commands
  -n            non-interactive mode, will not prompt user
  -P            preserve group vector instead of setting to target's
  -p prompt     use specified password prompt
  -r role       create SELinux security context with specified role
  -S            read password from standard input
  -s [command]  run a shell as target user
  -t type       create SELinux security context with specified role
  -U user       when listing, list specified user's privileges
  -u user       run command (or edit file) as specified user
  -V            display version information and exit
  -v            update user's timestamp without running a command
  --            stop processing command line arguments
    ：
-b：       ；
-h：    ；
-H： HOME          HOME    ；
-k：         ，        sudo        ；。
-l：                 ；
-p：           ；
-s<shell>：     shell；
-u<  >：            。       ，    root      ；
-v：        5  ；
-V ：      。