sudo:控制用户对系统命令的使用权限,root允许的操作。通过sudo可以提高普通用户的操作权限，不过这个权限是需要进行配置才可使用。
常用的命令展示
配置sudo的2种方式
1. visodu 编辑
visudo -c 检查语法命令，有报错可能导致系统起不来，所以编辑之前需要备份，编辑后最好检查一下用法
2. vi /etc/sudoers(98gg 可以快速跳转) 但是visudo功能更强大
Syntax: user MACHINE=COMMANDS # sudo 语法
root ALL=(ALL) ALL # (All)表示允许用户以哪个用户的权限做事情
omc ALL=(ALL) ALL # omc用户在任何机器上，可以只需任何用户的任何命令 == root用户
omc ALL=(ALL) NOPASSWD: ALL # 免密而且omc用户在任何机器上，可以只需任何用户的任何命令
ftl ALL=(ALL) /bin/cp,/bin/touch # 只允许ftl用户只需root用户的cp,touch命令
取消sudo必须需要tty才能执行的限制
编辑 /etc/sudoers ，找到 Defaults requiretty, 然后注释掉这行：
注： /etc/sudoers 这个是一个权限很小的文件(440)
visudo的参数
The options are as follows:
-c Enable check-only mode. The existing sudoers file will be checked for syntax errors, owner
and mode. A message will be printed to the standard output describing the status of
-c Enable check-only mode. The existing sudoers file will be checked for syntax errors, owner
and mode. A message will be printed to the standard output describing the status of
sudoers unless the -q option was specified. If the check completes successfully, visudo
will exit with a value of 0. If an error is encountered, visudo will exit with a value of
1.
-f sudoers Specify and alternate sudoers file location. With this option visudo will edit (or check)
the sudoers file of your choice, instead of the default, /etc/sudoers. The lock file used
is the specified sudoers file with “.tmp” appended to it. In check-only mode only, the
argument to -f may be ‘-’, indicating that sudoers will be read from the standard input.
-h The -h (help) option causes visudo to print a short help message to the standard output and
exit.
-q Enable quiet mode. In this mode details about syntax errors are not printed. This option
is only useful when combined with the -c option.
-s Enable strict checking of the sudoers file. If an alias is used before it is defined,
visudo will consider this a parse error. Note that it is not possible to differentiate
between an alias and a host name or user name that consists solely of uppercase letters,
digits, and the underscore (‘_’) character.
-V The -V (version) option causes visudo to print its version number and exit.