怎样使用tar命令打包(备份)文件?
A:Thesyntaxoftaris:
tar[options][files]
Theoptionsusedmostoftenwithtarareasfollows:
cCreatesanewbackup,overwritinganyfilesalreadyonthebackupdestination.
xExtractsfilesfrombackupmedia.
tListsthecontentsofbackupmedia.
vDisplaysthenameofeachfilebeingprocessed.
fCreatesbackupsonaspecifieddevice.
uAddsfilestothebackupiftheyarenotalreadythere,oriftheyhavebeenmodifiedsincetheywerelastwrittenonthebackup.
步骤：
1)估算打包文件的大小，确定使用档案媒体(archivemedia)的空间，用命令du-s
例如：
$lf
a.out*fork.cmboxtime.c
atoi.cint.cmemcpy.cvi
$du-s
296.
$
该例显示的296代表thetotalnumberof512-byteblocks,计算：512*296/1024=148kilobytes.
2)制作备份，用命令tarcvf/dev/fd0135ds18.(将该目录下的所有内容备份到1.44英寸软盘中whereccausesanewbackuptobecreated,vcauseseachfiletobedisplayedasthebackinguptakesplace,andfcausesthesubsequentargument--/dev/fd0135ds18tobethedestinationofthebackup.)
注：平时硬盘上的备份，我们一般用命令tarcvffilename.tar.
例如：
$tarcvfwuyd.tar.
a./.profile2tapeblocks
a./.lastlogin0tapeblocks
a./mbox10tapeblocks
a./fork.c2tapeblocks
a./memcpy.c1tapeblocks
a./.sh_history3tapeblocks
a./a.out91tapeblocks
a./time.c1tapeblocks
a./vi169tapeblocks
a./int.c1tapeblocks
a./atoi.c1tapeblocks
tar:sameasarchivefile:./wuyd.tar
a./.scoadmin.pref1tapeblocks
$lf
a.out*fork.cmboxtime.cwuyd.tar
atoi.cint.cmemcpy.cvi
我们还可以用命令tarcvf/dev/fd0135ds18./filename将该目录下的名为filename的文件备份到archivemedia中
怎样列出tar文档的内容?
A:tartvf/dev/fd0135ds18
tartvffilename.tar
例如：
$tartvfwuyd.tar
tar:blocksize=20
rw-------203/50896Sep1715:072003./.profile
r--------203/210Sep2419:492003./.lastlogin
rw-------203/504720Sep2111:172003./mbox
rw-r--r--203/50583Sep1715:272003./fork.c
rw-r--r--203/50218Sep1720:222003./memcpy.c
rw-------203/501474Sep2420:262003./.sh_history
rwxr-xr-x203/5046224Sep2221:002003./a.out
rw-r--r--203/50341Sep1909:022003./time.c
rw-r--r--203/5086283Sep2109:142003./vi
rw-r--r--203/5093Sep2110:532003./int.c
rw-r--r--203/50144Sep2221:002003./atoi.c
rw-r--r--0/341Sep2320:342003./.scoadmin.pref
$
怎样从tar文档中导出文件?
A:tarxvf/dev/fd0135ds18
tarxvffilename.tar
例如：
$mkdiruu;cpwuyd.tar./uu
$lf
a.out*fork.cmboxtime.cvi
atoi.cint.cmemcpy.cuu/wuyd.tar
$cduu
$tarxvfwuyd.tar
tar:blocksize=20
x./.profile,896bytes,2tapeblocks
x./.lastlogin,0bytes,0tapeblocks
x./mbox,4720bytes,10tapeblocks
x./fork.c,583bytes,2tapeblocks
x./memcpy.c,218bytes,1tapeblocks
x./.sh_history,1474bytes,3tapeblocks
x./a.out,46224bytes,91tapeblocks
x./time.c,341bytes,1tapeblocks
x./vi,86283bytes,169tapeblocks
x./int.c,93bytes,1tapeblocks
x./atoi.c,144bytes,1tapeblocks
x./.scoadmin.pref,41bytes,1tapeblocks
$
我们可用命令tarxvf/dev/fd0135ds18./filename导出archivemedia中的单个文件
例如：
$lf
wuyd.tar
$tarxvfwuyd.tar./time.c
tar:blocksize=20
x./time.c,341bytes,1tapeblocks
$lf
time.cwuyd.tar
$
怎样使用tar命令提供的简写形式?
A:
$more/etc/default/tar
#@(#)def135.src25.294/07/25
#
#Copyright(C)1987-1994TheSantaCruzOperation,Inc.
#AllRightsReserved.
#Theinformationinthisfileisprovidedfortheexclusiveuseof
#thelicenseesofTheSantaCruzOperation,Inc.Suchusershavethe
#righttouse,modify,andincorporatethiscodeintootherproducts
#forpurposesauthorizedbythelicenseagreementprovidedtheyinclude
#thisnoticeandtheassociatedcopyrightnoticewithanysuchproduct.
#Theinformationinthisfileisprovided"ASIS"withoutwarranty.
#
#default/tar-archivedevices:tar(C)
#
#deviceblocksizetape
#
archive0=/dev/rfd048ds918360n
archive1=/dev/rfd148ds918360n
archive2=/dev/rfd096ds15101200n
archive3=/dev/rfd196ds15101200n
#archive4=/dev/rfd096ds918720n
archive4=/dev/rfd0135ds918720n
archive5=/dev/rfd1135ds918720n
#archive5=/dev/rfd196ds918720n
archive6=/dev/rfd0135ds18181440n
archive7=/dev/rfd1135ds18181440n
archive8=/dev/rct0200y
archive9=/dev/rctmini200y
archive10=/dev/rdsk/fp03d18720n
archive11=/dev/rdsk/fp03h181440n
archive12=/dev/rdsk/fp03v211020330n
#
#Thedefaultdeviceintheabsenceofanumericor"-fdevice"argument
archive=/dev/rfd0135ds18181440n
$
从上面可以看出4代表/dev/rfd0135ds9设备，而默认的设备是/dev/rfd0135ds18，所以tarxvf/dev/rfd0135ds9./filename可以简写为tarxv4./filename,而tarcvf/dev/fd0135ds18.可以简写为tarcv.