sed字符串对象【替换】

sed字符串替换

[position]s/source/destination/flags

Position is optional。

一、S Specific Parameters

（1）&

[nick@d01 bash]$ cat sedrep.txt w1 test my car [nick@d01 bash]$sed -e 's/w1/w2/g' sedrep.txt w2 test my car [nick@d01 bash]$sed -e 's/w1/&w2/g' sedrep.txt w1w2 test my car

（2）/n

[nick@d01 bash]$ cat sedrep.txt w1 test my car [nick@d01 bash]$ sed -e 's//(test/)/(my/)/(car/)//2/3/1/' sedrep.txt w1 mycartest

Blue font string matchs “test my car”. And there are two blanks among/(test/), /(my/) and /(car/).

/(…./) is used to keep the value， which may be referenced by number index.

二、Flags Parameters

(1)g

replace in global space

[nick@d01 bash]$ cat sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1 w1 w1 w1 [nick@d01 bash]$sed -e 's/w1/&w2/g' sedrep.txt w1w2 w1w2 w1w2 w1w2 w1w2 w1w2 test my car w1w2 w1w2 w1w2 w1w2

(2)number

replace the nth string in this line

[nick@d01 bash]$ cat sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1 w1 w1 w1 [nick@d01 bash]$sed -e 's/w1/&w2/2' sedrep.txt w1 w1w2 w1 w1 w1 w1 test my car w1 w1w2 w1 w1 [nick@d01 bash]$ sed -e 's/w1/&w2/1' sedrep.txt w1w2 w1 w1 w1 w1 w1 test my car w1w2 w1 w1 w1w2

(3)p

replace the ith string in every line， and print out

[nick@d01 bash]$ cat sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1 w1 w1 w1 [nick@d01 bash]$sed -e 's/w1/&w2/p' sedrep.txt w1w2 w1 w1 w1 w1 w1 w1w2 w1 w1 w1 w1 w1 test my car w1w2 w1 w1 w1w2 w1 w1 w1w2 w1w2

(4)w

write the result to one file

[nick@d01 bash]$ cat sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1 w1 w1 w1 [nick@d01 bash]$ sed -e 's/w1/&w2/2w sedrep2.txt' sedrep.txt w1 w1w2 w1 w1 w1 w1 test my car w1 w1w2 w1 w1

三、Optional Position Parameter

[nick@d01 bash]$ cat sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1 w1 w1 w1 w1 [nick@d01 bash]$sed -e '/car/s/w1/&w2/g' sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1w2 w1 w1 w1 w1 [nick@d01 bash]$sed -e '1,/car/s/w1/&w2/g' sedrep.txt w1w2 w1w2 w1w2 w1w2 w1w2 w1w2 test my car w1w2 w1 w1 w1 w1 [nick@d01 bash]$sed -e '/car/,3s/w1/&w2/g' sedrep.txt w1 w1 w1 w1 w1 w1 test my car w1w2 w1w2 w1w2 w1w2 w1 [nick@d01 bash]$sed -e '1,2s/w1/&w2/g' sedrep.txt w1w2 w1w2 w1w2 w1w2 w1w2 w1w2 test my car w1w2 w1 w1 w1 w1

sed -i write changes into file directly