User rights and system timing

{2. User Rights List}

[1. Definition of permission list]

Specify a record table that special users have special permissions on a file

[2. Recognition of permission lists]

-rw-rw-r--+ 1 root root Oct 17:38 file * * Permission bit has plus permission list open

-rw-rw-r--. 1 root root Oct 17:39 westos * * Permission bit is. permission list not activated

[3. View of permission list]

Getfacl file

* File:file * * file

* Owner:root * * File Owner

* Group:root * * File All Groups

user::rw-* * File Owner permissions

user:test:rw-* * Special specified User (test) permissions

group::r--* Group Permissions

mask::rw-* * Privilege threshold

other::r--* * Other people rights

[4. How to set ACL list]

Setfacl-m u:username: Permissions file

Setfacl-m U:TEST:RW File * * Specifies that the test user can read writable

Setfacl-x u:student File * * Delete student user information from the list

Setfacl-x g:student File * * Delete student group information from the list

Setfacl-b file * * Close list

[5.mask Privilege Threshold]

If you perform chmod on a file with a permission list , it is likely that the mask in this permission list will be modified

Mask Maximum permission value that is available to a particular user

Setfacl-m m: Permissions * * Modify the value of mask

[6. Default Permissions]

When we need to create a new file or directory in the specified directory that has special permissions for the specified user

Setfacl-m d:u:username: Permissions file

Default permissions do not take effect on existing files

Default permissions do not take effect on the directory itself

dumpe2fs/dev/vda1 | grep mount

Tune2fs-o acl/dev/vda1

Tune2fs-o ^acl/dev/vda1

{3. System delay and timing mechanism}

[1.at Delay]

At time

At> Action

At>ctrl +d

At> <EOT>

At-l

ATRM Task number

When an action is executed with output

The output is sent as a message to the person's initiator

At user's black and white list

/etc/at.deny * * exists and takes effect by default

/etc/at.allow * * Default does not exist, once present,/etc/at.deny invalid

[2. Regular tasks]

Crontab-u Username-e set up regular tasks

MM HH dd mm WW

*   *   *   *   *

minutes hours Day month week

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MM/2 * * Every 2 minutes

HH1-HH2 * * How many points to how many points

HH1,HH2 * * How many points and how many points

Crontab-l * * View recurring tasks

Crontab-u username-r * * Delete recurring tasks

The way the file originated

Vim/etc/cron.d/filename

MM HH dd mm WW USERNAME action

Echo ' mm HH dd mm WW USERNAME action ' >/etc/cron.d/filename * * will ' mm HH DD MM WW USERNAME action ' import/etc/cron.d/filename

Black and white list

/etc/cron.deny blacklist configuration file

/etc/cron.allow White List configuration file

[3. System temp File Management]

Vim/user/lib/tmpfile.d/*.conf

Type filename Perm user group time

D/mnt/westos 1777 root Root 10s

Systemd-tmpfiles--creat/usr/lib/tmpfiles.d/* Building Services

Systemd-tmpfiles--clean/usr/lib/tmpfiles.d/* Close Service

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User rights and system timing