linux chkconfig and umask

jydg

1, linux chkconfig command
description:

    this command use to update(add or delete) and search system running level info

usage:
    chkconfig [--add][--del][--list] system service

    chkconfig [--level <level number>] system service [on/off/reset]
level number:
0,shutdown server
1,simple user mode
2,multi-user mode without netowrk connection
3,multi-user mode with netowrk connection
4,unavailable
5,multi-user mode with graphical interfaces
6, reboot
examples:


[root@localhost james]# chkconfig --list |head -5    ## list all system services
NetworkManager  0:off   1:off   2:on    3:on    4:on    5:on    6:off
acpid           0:off   1:off   2:on    3:on    4:on    5:on    6:off
atd             0:off   1:off   2:off   3:on    4:on    5:on    6:off
auditd          0:off   1:off   2:on    3:on    4:on    5:on    6:off
autofs          0:off   1:off   2:off   3:on    4:on    5:on    6:off

[root@localhost james]# chkconfig --list | grep mysqld    ## check mysqld service from all system services
mysqld          0:off   1:off   2:off   3:on    4:on    5:on    6:off
[root@localhost james]# chkconfig --del mysqld      ## delete mysqld service
[root@localhost james]# chkconfig --list | grep mysql   
[root@localhost james]# chkconfig --add mysqld    ## add mysqld service
[root@localhost james]# chkconfig --list | grep mysql
mysqld          0:off   1:off   2:off   3:off   4:off   5:off   6:off     ##  here find all level down ,
[root@localhost james]# chkconfig --level 345 mysqld on     ## so can up level 3 4 5
[root@localhost james]# chkconfig --list | grep mysql  
mysqld          0:off   1:off   2:off   3:on    4:on    5:on    6:off
[root@localhost james]# chkconfig --list  mysqld            ## list mysqld service
mysqld          0:off   1:off   2:off   3:on    4:on    5:on    6:off
[root@localhost james]# chkconfig mysqld on         ## default up service to 2345
[root@localhost james]# chkconfig --list  mysqld
mysqld          0:off   1:off   2:on    3:on    4:on    5:on    6:off
[root@localhost james]#
refer to http://www.cnblogs.com/panjun-Donet/archive/2010/08/10/1796873.html
2,linux umask command
file privileges :


[root@TKE/DEVEL_NEW tmp]# ls -lart vfm.txt
-rw-r--r-- 1 apache apache 4 Jan 10 13:00 vfm.txt
  -              rw-                r--                  r--                [+]           apache     apache   4 Jan 10 13:00   vfm.txt
type   owner access   group access   others access   ACL access      owner     group       file date          file-name
type:
usually : '-' refer to normal file
'd'    refer to directory
'l'    refer to soft symbole file
owner/group/others :
'---'  refer to r(read)/w(write)/x(execute)  or 421
if you want to change file/directory privileges ,you can use chmod
chmod 775 vfm.txt
chmod (a/u/g/o)(+/-/=)(rwx) file
e.g.
chown u+x vfm.txt

chown 755 vfm.txt

chmod u=rwx,g=rx,o=x vfm.txt
chmod =r vfm.txt  ## a is default ,refer to all user
chmod 444 vfm.txt    ## equal to above one
chmod a-w,a+r vfm.txt ##equal to above
if you want to change file/directory owner/group ,you can use chown
chown owner:group file/directory    ## change owner and group at the same time
chown owner:   file/directory      ## change owner and group to the same "owner"
chown :group  file/directory      ## only change group
or you can use chgrp ,just change group
chgrp group file/directory


examples :
[root@localhost james]# ll
drwxr-xr-x. 2 root root 4096 Jan 10 16:58 tmp1
[root@localhost james]# chown james: tmp1
[root@localhost james]# ll
drwxr-xr-x. 2 james james 4096 Jan 10 16:58 tmp1


[root@localhost james]# chown :root tmp1
[root@localhost james]# ll
drwxr-xr-x. 2 james root 4096 Jan 10 16:58 tmp1
[root@localhost james]# chown eagle:colin tmp1

[root@localhost james]# ll
drwxr-xr-x. 2 eagle colin 4096 Jan 10 16:58 tmp1

[root@localhost james]# chgrp james tmp1
[root@localhost james]# ll
drwxr-xr-x. 2 eagle james 4096 Jan 10 16:58 tmp1




default umask is 022


[root@localhost james]# pwd
/tmp/james
[root@localhost james]# umask
0022
[root@localhost james]# mkdir tmp1


[root@localhost james]# touch tmp2.txt
[root@localhost james]# ls -lrt
total 4
drwxr-xr-x. 2 root root 4096 Jan 10 16:58 tmp1
-rw-r--r--. 1 root root    0 Jan 10 16:59 tmp2.txt
so folder privilege is  777-022=755  
file privilege is 666-022=644
modify umask value

[root@localhost james]# umask 0002
[root@localhost james]# umask
0002
[root@localhost james]# mkdir tmp3
[root@localhost james]# touch tmp4.txt
[root@localhost james]# ls -lrt
total 8
drwxr-xr-x. 2 root root 4096 Jan 10 16:58 tmp1
-rw-r--r--. 1 root root    0 Jan 10 16:59 tmp2.txt
drwxrwxr-x. 2 root root 4096 Jan 10 17:01 tmp3
-rw-rw-r--. 1 root root    0 Jan 10 17:01 tmp4.txt
[root@localhost james]#
so now folder privilege is 777-002=775
file privilege is 666-004=664
change like this only exist in current seesion ,so now open another session to check umask values

[root@localhost ~]# umask
0022
[root@localhost ~]#
if you want to set it permanently ,you can write this value to

/etc/profile
~/.profile
~/.bash_profile
so after restart server or open another session ,the umask value is the one you modify
session one :(/etc/profile)

if [ $UID -gt 199 ] && [ "`id -gn`" = "`id -un`" ]; then
    umask 002
else
    umask 002  (022 to 002)
fi
session two:

[root@localhost ~]# umask
0002
[root@localhost ~]#