问题
this is my sample text file :
asdas //<<<TAG this should be removed //TAG>>> this should be there //<<<TAG T > asd asd //TAG>>>
for which i want o/p as :
asdas this should be there
Basically i m trying to find lines between "//<<>>" (including these lines too) and delete them.
I tried using sed
sed -n '1h;1!H;${;g;s///<<]*TAG>>>//g;p;}' < test.txt
But some how it did not produced correct output. The second tag which contained ">" symbol failed in regex. Not sure where i m going wrong?
Any idea how to do it ?
回答1:
If you are trying to delete lines with the literal text 'TAG', try:
sed '/\/\/<<<TAG/,/\/\/TAG>>>/d'
From your comments, it appears that TAG may not be literal, in which case:
sed '/^\/\/<</,/^\/\/.*>>/d'
This can be simplified by using a different delimiter:
sed '@^//<<<@,@^//.*>>>@d'
回答2:
Rather than using the sed solution I gave, you might like either of these in perl and awk:
perl -ne 'print if !( m@//<<<TAG@ .. m@//TAG>>>@ )'
awk '/\/\/<<<TAG/,/\/\/TAG>>>/ {next} 1'
Given that I think you really do not want TAG to be a constant, the cleanest solution I know of is the perl variant:
perl -ne 'print if !( m@^//<<<(.*)@ .. m@^//$1>>>$@ )'
回答3:
In addition the search delimiters in sed can be changed by escaping the first delimiter:
sed '\|^//<<<|,\|^//.*>>>|d' file
Awk version the matches the end with the same tag name:
awk -F'//<<<|//|>>>' '$2{p=$2; while(getline && p!=$2); next}1' file
来源：https://stackoverflow.com/questions/1221245/sed-multiline-replace