grep 用法
Grep : g (globally) search for a re (regular expression ) and p (print ) the results.
1、参数：
-I：忽略大小写
-c：打印匹配的行数
-l：从多个文件中查找包含匹配项
-v：查找不包含匹配项的行
-n：打印包含匹配项的行和行标
2、RE（正则表达式）
\忽略正则表达式中特殊字符的原有含义
^匹配正则表达式的开始行
$匹配正则表达式的结束行
\<从匹配正则表达式的行开始
\>;到匹配正则表达式的行结束
[]单个字符；如[A]即A符合要求
[-]范围；如[A-Z]即A，B，C一直到Z都符合要求
.所有的单个字符
*所有字符，长度可以为0
3、举例
#ps-ef|grepin.telnetd
root19955181013:43:53?0:00in.telnetd
#moresize.txtsize文件的内容
b124230
b034325
a081016
m7187998
m7282064
a022021
a061048
m9324822
b103303
a013386
b044525
m8987131
B081016
M45678
B103303
BADc2345
#moresize.txt|grep'[a-b]'范围；如[A-Z]即A，B，C一直到Z都符合要求
b124230
b034325
a081016
a022021
a061048
b103303
a013386
b044525
#moresize.txt|grep'[a-b]'*
b124230
b034325
a081016
m7187998
m7282064
a022021
a061048
m9324822
b103303
a013386
b044525
m8987131
B081016
M45678
B103303
BADc2345
#moresize.txt|grep''单个字符；如[A]即A符合要求
b124230
b034325
b103303
b044525
#moresize.txt|grep'[bB]'
b124230
b034325
b103303
b044525
B081016
B103303
BADc2345
#grep'root'/etc/group
root::0:root
bin::2:root,bin,daemon
sys::3:root,bin,sys,adm
adm::4:root,adm,daemon
uucp::5:root,uucp
mail::6:root
tty::7:root,tty,adm
lp::8:root,lp,adm
nuucp::9:root,nuucp
daemon::12:root,daemon
#grep'^root'/etc/group匹配正则表达式的开始行
root::0:root
#grep'uucp'/etc/group
uucp::5:root,uucp
nuucp::9:root,nuucp
#grep'\<uucp'/etc/group
uucp::5:root,uucp
#grep'root$'/etc/group匹配正则表达式的结束行
root::0:root
mail::6:root
#moresize.txt|grep-i'b1..*3'-i：忽略大小写
b124230
b103303
B103303
#moresize.txt|grep-iv'b1..*3'-v：查找不包含匹配项的行
b034325
a081016
m7187998
m7282064
a022021
a061048
m9324822
a013386
b044525
m8987131
B081016
M45678
BADc2345
#moresize.txt|grep-in'b1..*3'
1:b124230
9:b103303
15:B103303
#grep'$'/etc/init.d/nfs.server|wc-l
128
#grep'\$'/etc/init.d/nfs.server|wc–l忽略正则表达式中特殊字符的原有含义
15
#grep'\$'/etc/init.d/nfs.server
case"$1"in
>;/tmp/sharetab.$$
["x$fstype"!=xnfs]&&\
echo"$path\t$res\t$fstype\t$opts\t$desc"\
>;>;/tmp/sharetab.$$
/usr/bin/touch-r/etc/dfs/sharetab/tmp/sharetab.$$
/usr/bin/mv-f/tmp/sharetab.$$/etc/dfs/sharetab
if[-f/etc/dfs/dfstab]&&/usr/bin/egrep-v'^[]*(#|$)'\
if[$startnfsd-eq0-a-f/etc/rmmount.conf]&&\
if[$startnfsd-ne0];then
elif[!-n"$_INIT_RUN_LEVEL"];then
while[$wtime-gt0];do
wtime=`expr$wtime-1`
if[$wtime-eq0];then
echo"Usage:$0{start|stop}"
#moresize.txt
thetestfile
theirarefiles
Theend
#grep'the'size.txt
thetestfile
theirarefiles
#grep'\<the'size.txt
thetestfile
theirarefiles
#grep'the\>;'size.txt
thetestfile
#grep'\<the\>;'size.txt
thetestfile
#grep'\<[Tt]he\>;'size.txt
thetestfile
Theend