Name     Chinese   English   Math    Average
DmTsai        80        60     92      77.33
VBird         75        55     80      70.00
Ken           60        90     70      73.33

[root@linux ~]# printf 'CL榡' ڤe
ѼơG
榡譱XӯS˦G
       \a    ĵinX
       \b    ˰h(backspace)
       \f    Mù (form feed)
       \n    Xs@
       \r    Y Enter 
       \t     [tab] 
       \v     [tabl] 
       \xNN  NN ƪƦrAiHഫƦrrC
 C {yA`ܼƮ榡
       %ns    n OƦrA s N string AYh֭ӦrF
       %ni    n OƦrA i N integer AYh־ƦơF
       %N.nf  n P N OƦrA f N floating (BI)ApGpƦơA
             ]ڦ@nQӦơApIAY %10.2f oI
dҡG

dҤ@GNWYܦɮסAȦCXmWPZG( [tab] j
[root@linux ~]# printf '%s\t %s\t %s\t %s\t %s\t \n' `cat printf.txt`
Name     Chinese         English         Math    Average
DmTsai   80      60      92      77.33
VBird    75      55      80      70.00
Ken      60      90      70      73.33
# ]ڱNWɮצs printf.txt ɮɦWAhiQΤWרҡA
# NCӳrH [tab] j}CѤWXӬݡAMĤGHO OK A
# OĤ@h]Ydzr׸AҥHNLkFI %s ܥHr (string)
# 觋Ӯi{ӤeCӨCӤehH \t Y [tab] ӹj}ڡI

dҤGGNWzĤGHAOHrBơBpIܡG
[root@linux ~]# printf '%10s %5i %5i %5i %8.2f \n' `cat printf.txt |\
> grep -v Name`
    DmTsai    80    60    92    77.33
     VBird    75    55    80    70.00
       Ken    60    90    70    73.33
# oӮɭԪXiNFIڱNXӤePƮ榡ӿXA
# ̦쪺ӬO %8.2f oӶؤFIڥiHw藍PpƦƨӶi榡XA
# ҦpܦUˤlɡAzۤvլݬݡA|OX򵲪GI
# printf '%10s %5i %5i %5i %8.1f \n' `cat printf.txt | grep -v Name`

dҤTGCXƭ 45 NrH
[root@linux ~]# printf '\x45\n'
E
# oF]ܦnLiHNƭഫrApGz|g script ܡA
# iHۦդ@UA 20~80 ƭȥNrOԣI ^_^

[root@linux ~]# sed [-nefr] [ʧ@]
ѼơG
-n  GϥΦwR(silent)ҦCb@ sed ΪkAҦӦ STDIN 
      Ƥ@볣|QCXùWCpG[W -n ѼƫAhugL
      sed SBz@(Ϊ̰ʧ@)~|QCXӡC
-e  GbOCҦWi sed ʧ@sF
-f  GN sed ʧ@gb@ɮפA -f filename hiH filename  
      sed ʧ@F
-r  Gsed ʧ@䴩OWܪkykC(w]O¦Wܪkyk)
-i  GקŪɮפeAӤOѿùXC

ʧ@G  [n1[,n2]]function
n1, n2 Go|sbA@Nyܶiʧ@ơzA|ҨӻApGڪʧ@
         Oݭnb 10  20 椧i檺Ahy 10,20[ʧ@欰] z

function UoǩNNG
a   GsWA a ᭱iHrAӳoǦr|bs@X{(ثeU@)
c   GNA c ᭱iHrAoǦriHN n1,n2 I
d   GRA]ORڡAҥH d ᭱q`NNF
i   GJA i ᭱iHrAӳoǦr|bs@X{(ثeW@)F
p   GCLAYNYӿܪƦLXCq` p |PѼ sed -n @_B@
s   GNAiHiNu@Iq`o s ʧ@iHft
      WܪkIҦp 1,20s/old/new/g NOաI
dҡG

dҤ@GN /etc/passwd eCXAåBڻݭnCL渹APɡAбN 2~5 RI
[root@linux ~]# nl /etc/passwd | sed '2,5d'
     1  root:x:0:0:root:/root:/bin/bash
     6  sync:x:5:0:sync:/sbin:/bin/sync
     7  shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
.....(᭱ٲ).....
# ݨFaH] 2-5 浃LRFAҥHܪƤANS 2-5 o
# t~A`N@UA쥻ӬOnUF sed -e ~AS -e ]աI
# Pɤ]n`NOA sed ᭱ʧ@AаȥH '' ӳ޸AI
# ӡApGunR 2 AiHϥ nl /etc/passwd | sed '2d' ӹFA
# ܩ 3 ̫@AhO nl /etc/passwd | sed '3,$d' աI 

dҤGGӤWDAbĤG(YO[bĤT)[Wydrink tea?zrˡI
[root@linux ~]# nl /etc/passwd | sed '2a drink tea'
     1  root:x:0:0:root:/root:/bin/bash
     2  bin:x:1:1:bin:/bin:/sbin/nologin
drink tea
     3  daemon:x:2:2:daemon:/sbin:/sbin/nologin
# KKIb a ᭱[WrNwNX{bĤG᭱oIpGOnbĤGeOH
# nl /etc/passwd | sed '2i drink tea' NաI

dҤTGbĤG᭱[JrAҦpyDrink tea or .....zydrink beer?z
[root@linux ~]# nl /etc/passwd | sed '2a Drink tea or ......\
> drink beer ?'
     1  root:x:0:0:root:/root:/bin/bash
     2  bin:x:1:1:bin:/bin:/sbin/nologin
Drink tea or ......
drink beer ?
     3  daemon:x:2:2:daemon:/sbin:/sbin/nologin
# oӽdҪIOAڭ̥iHsWu@IiHsWnX
# OC@椧nHϱ׽u \ Ӷis檺W[IҥHAWҤlA
# ڭ̥iHo{bĤ@檺̫᭱N \ sbաIO@wnI

dҥ|GڷQN2-5檺eNyNo 2-5 numberzOH
[root@linux ~]# nl /etc/passwd | sed '2,5c No 2-5 number'
     1  root:x:0:0:root:/root:/bin/bash
No 2-5 number
     6  sync:x:5:0:sync:/sbin:/bin/sync
# SF 2-5 AKKKKIڭ̭nƴNX{աI

dҤGȦCX 5-7 
[root@linux ~]# nl /etc/passwd | sed -n '5,7p'
     5  lp:x:4:7:lp:/var/spool/lpd:/sbin/nologin
     6  sync:x:5:0:sync:/sbin:/bin/sync
     7  shutdown:x:6:0:shutdown:/sbin:/sbin/shutdown
# n[ -n ѼƩOHziHۦUF sed '5,7p' NDFI(5-7|ƿX)
# S[W -n ѼƮɡAXƥiOtܦhI

dҤGڭ̥iHϥ ifconfig ӦCX IP AYȭn eth0  IP ɡH
[root@linux ~]# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:51:FD:52:9A:CA
          inet addr:192.168.1.12  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::250:fcff:fe22:9acb/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
.....(HUٲ).....
# Aڭ̭nuO inet addr:..@ӤwAҥHoAQ grep P sed Ӯ
[root@linux ~]# ifconfig eth0 | grep 'inet ' | sed 's/^.*addr://g' | \
> sed 's/Bcast.*$//g'
# ziHNCӺ޽u (|) L{}ӰAN|o]oI
# hYhAN|oڭ̩һݭn IP YO 192.168.1.12 o

dҤCGN /etc/man.config ɮתeA MAN ]wNXӡAneC
[root@linux ~]# cat /etc/man.config | grep 'MAN'| sed 's/#.*$//g' | \
> sed '/^$/d'
# C@AY # ܸӦ欰ѡAOn`NOAɭԡA
# ѨäOgbĤ@ӦrAYOgbYӫOApUҼˡG
# yshutdown -h now # oӬOOzA # NbOFC
# ]Aڭ̤~|ϥΨN #.*$ oӥWܪkI

dҤKGQ sed b ~/.bashrc ̫@[Jy# This is a testz
[root@linux ~]# sed -i '$a # This is a test'  ~/.bashrc
# WY -i ѼƥiHA sed hק᭱ɮפeIӤOѿùXC
# ܩ󨺭 $a  hN̫@~sWNC

[root@linux ~]# awk '1{ʧ@1} 2{ʧ@2} ...' filename

[root@linux ~]# last
dmtsai   pts/0        192.168.1.12     Mon Aug 22 09:40   still logged in
root     tty1                          Mon Aug 15 11:38 - 11:39  (00:01)
reboot   system boot  2.6.11           Sun Aug 14 18:18         (7+15:41)
dmtsai   pts/0        192.168.1.12     Fri Aug 12 12:07 - 12:08  (00:01)

[root@linux ~]# last | awk '{print $1 "\t" $3}'
dmtsai  192.168.1.12
root    Mon
reboot  boot
dmtsai  192.168.1.12

[root@linux ~]# last | awk '{print $1 "\t lines: " NR "\t columes: " NF}'
dmtsai   lines: 1        columes: 10
root     lines: 2        columes: 9
reboot   lines: 3        columes: 9
dmtsai   lines: 4        columes: 10