随手笔记 sed , linux 文本处理工具

nl ~/text.txt | sed '2,5d' 在输出中删除2～5行的内容
nl ~/text.txt | sed '2d' 在输出中删除第2行的内容
nl ~/text.txt | sed '2, $d' 在输出中删除2~$(最后)行的内容
nl ~/text.txt | sed '2a drink tea' 在输出中删除2行后加上 drink tead 字符
nl ~/text.txt | sed '2i drink tea' 在输出中删除2行前加上 drink tead 字符
nl ~/text.txt | sed '2i drink \ >tea' 在输出中删除2行前加上 drink \n tead 两行字符
nl ~/text.txt | sed '2,5c No 2-5 number' 在输出中， 将2-5行字符替换为No 2-5 number
nl ..... | sed -n '1,3p' 输出1-3行字符

sed 's/要被替换的字符/新的字符/g'
cat /etc/man_db.config | grep 'MAN'
cat /etc/man_db.config | grep 'MAN' | sed 's/#.*$//g'	将以# 开头的换成空字符 
cat /etc/man_db.config | grep 'MAN' | sed 's/#.*$//g' | sed '/^$/d' 删除空字符行

nl ~/test.txt | grep '^ *[0-9]*[[:blank:]]*test line [0-9]*'
nl ~/test.txt | sed '/^ *[0-9]*[[:blank:]]*test line [0-9]*/d' 删除和匹配的字符行
nl ~/test.txt | sed '/*test line [0-9]*/d'  效果同上句命令一致

sed 直接修改文件 sed -i function
sed -i 's/\.$/\!/g' test.txt 将test.txt中句末的'.'换成'!'
sed -i '$a #this is a test' test.txt 在test.txt文件末加上 # this is a test 字符串.

扩展的正则表达式： egrep命令， 或者grep -E 命令代替grep命令  

test.txt 内容如下0

Type some words in this nano editor program!
You can use [ctrl] plus keywords to go to some function!
Bye bye~~~~!
test line 4
test line 5
test line 6
test line 7
test line 8
test line 9
test line 10
test line 11

test.txt 通过nl输出如下

     1	Type some words in this nano editor program!
     2	You can use [ctrl] plus keywords to go to some function!
     3	Bye bye~~~~!
     4	test line 4
     5	test line 5
     6	test line 6
     7	test line 7
     8	test line 8
     9	test line 9
    10	test line 10
    11	test line 11
    12	# This is a test.

随手记一记， 以后也许用不到吧！