, :
# tar cvf backup.tar /etc
# gzip -9 backup.tar
backup.tar.gz. :
# gunzip backup.tar.gz
# tar xvf backup.tar
, , .
UNIX,
# tar cvf - /etc | gzip -9c > backup.tar.gz
tar-, /etc, ``-'', . gzip, backup.tar.gz. -c gzip , gzip , backup.tar.gz.
, , :#gunzip -cbackup.tar.gz | tarxvf
, gunzip backup.tar.gz . tar, ``-'', .
tar z, - , gzip. ,
# tarcvfzbackup.tar.gz /etc
# tarcvfbackup.tar /etc
# gzipbackup.tar
# tarxvfzbackup.tar.Z
# uncompress backup.tar.Z
# tar xvf backup.tar
:
1) Linux?
2) tar?
3) ?
4) gzip?
:
1. . . . 4- . 2015
2. . . Linux 4- - 2012
27. Linux. at. cron.
:
1. at
2. cron
3. anacron
Linux , - ( shell-) , , .
Linux- . at cron.
. at , - . - , cron crontab.
- , .
|
|
at
, , at (). at, . , /bin/sh.
at:
, 11 . at 23:00. - at >. , Enter. , , Ctrl+D. , , - .
POSIX.2. HH:MM ( HH - , MM - ). :
at 7 am 10202008 - 20- 2008 7
at 12:00 20.10.2008 - 20 2008 12
at 10 pmtoday - 10
at 3 amtomorrow - ( ) 3
, :
myjobs, , .
:
At 5 pm 10202008 - fmyjobs
, , atq, , :
, . atrm, . , atq.
at:
- m, , .
cron
cron - . , , cron. cron , . cron, crontab -, , /var/spool/cron/crontabs/. root.
/var/spool/cron/crontabs/ () . , test cron, - /var/spool/cron/crontabs/test. test .
, cron :
$ ps ax | grep [c]ron
cron . . cron - /etc/crontab. - 7 , , ..
|
|
/etc/crontab:
m | h | dom | mon | dow | user | command |
17 | * | * | * | * | root | cd / &&run-parts--report/etc/cron.hourly |
7- :
m - minute - - ; - (0-59)
h - hour - - ; (0-23) dom - day of month - - ; (1-31)
mon - month - - ; (1-12)
dow - day of week - - ; (0-7, 0 7 - , )
user - -
command - - , .
, , , . * - .
crontab - /etc/crond/, cron . , /etc/crontab. ( ).
crontab - , . crontab - crontab. crontab e, ( ) . , crontab - user, cron , /var/spool/cron/crontabs/ .
crontab - , /etc/cron.deny. , . . /etc/cron.allow.
/etc/crontab
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/
# run-parts
01 * * * * root nice -n 19 run-parts --report /etc/cron.hourly 02
4 * * * root nice -n 19 run-parts --report /etc/cron.daily 22 4 *
* 0 root nice -n 19 run-parts --report /etc/cron.weekly 42 4 1 *
* root nice -n 19 run-parts --report /etc/cron.monthly
SHELL -, PATH , MAILTO , , HOME crond.
, , . /etc/cron.hourly, /etc/cron.daily, /etc/cron.weekly, /etc/cron.monthly.
anacron
anacron cron, . anacron , , cron, , . , 7 . cron , 7 . 6 , , , 7:20. 7:20 7:00, , cron , .
anacron , ( , ), . , .
|
|
anacron . , , /etc/anacrontab root. cron , , anacron , .
/etc/anacrontab :
ID
:
1 5 cron.daily run-parts /etc/cron.daily
7 10 cron.weekly run-parts /etc/cron.weekly
30 75 cron.monthly run-parts /etc/cron.monthly
:
- 10 6 * * * root myscript - myscript , 6 10
- 0 5 1 * * root myscript - myscript 5
- 30 23 * * 1-5 root myscript - myscript ( ) 23 30
- 0 23 1,3,7,15 1,7 * root myscript - myscript 1,3,7,15- , 23
- 30 0-23/3 * * * root myscript - . 0:30, 3:30 ..
:
1) Linux?
2) at cron?
3) ?
4) anacron cron?
:
1. . . . 4- . 2015
2. . . Linux 4- - 2012
28. TCP/IP Linux.
:
1. Linux
2. Linux
3. IP- Linux
4. ARP-
UNIX (socket). , . . , , , . . , , TCP (Transmission Control Protocol ). UDP (User Data Protocol ). IP (Internet Protocol). . , . . , 32- ( ) IPv4 128- IPv6.