Suppose I have a string like this
<start><a></a><a></a><a></a></start>
I want to replace values inside <start></start> like this
<start><ab></ab><ab></ab><ab></ab><more></more><vale></value></start>
How do I do this using Sed?
asked May 6, 2013 at 22:56
codereviewanskquestions
14k31 gold badges104 silver badges171 bronze badges
Add a comment
|
4 Answers
Try this :
sed 's@<start>.*</start>@<start><ab></ab><ab></ab><ab></ab></start>@' file
Comments
I get this line with gnu sed :
sed -r 's#(<start>)(.*)(</start>)#echo "\1"$(echo "\2"\|sed "s:a>:ab>:g")"\3"#ge'
see example:
kent$ echo "<start><a></a><a></a><a></a><foo></foo><bar></bar></start>"|sed -r 's#(<start>)(.*)(</start>)#echo "\1"$(echo "\2"\|sed "s:a>:ab>:g")"\3"#ge'
<start><ab></ab><ab></ab><ab></ab><foo></foo><bar></bar></start>
note
this will replace the tags between <start>s which ending with a . which worked for your example. but if you have <aaa></aaa>:
you could do: (I break it into lines for better reading)
sed -r 's#(<start>)(.*)(</start>)
#echo "\1"$(echo "\2"\|sed "s:<a>:<ab>:g;s:</a>:</ab>:g")"\3"
#ge'
e.g.
kent$ echo "<start><a></a><a></a><a></a><aaa></aaa><aba></aba></start>" \
|sed -r 's#(<start>)(.*)(</start>)#echo "\1"$(echo "\2"\|sed "s:<a>:<ab>:g;s:</a>:</ab>:g")"\3"#ge'
<start><ab></ab><ab></ab><ab></ab><aaa></aaa><aba></aba></start>
Comments
sed 's/(\<\/?)a\>/\1ab\>/g' yourfile, though that would get <a></a> that was outside <start> as well...
3 Comments
Kent
not only
<a></a> outside <start> but also tags like <ha></ha> or <bla></bla>...
PaulProgrammer
I think I fixed it, but backreferences aren't something I normally use, so might be wrong.
Michel Keijzers
If you are not sure, then put it explicitly to the answer.
grep -rl 'abc' a.txt | xargs sed -i 's/abc/def/g'
