CentOS Question posted in
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General solutions to replace string regex preceded and followed by 'n' – CentOS

I have a file in CentOS which looks like following

[root@localhost nn]# cat -A excel.log
real1$
0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I$
real2$
0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I$
real3$
0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I$
real4$
0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I1^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I$
real5$
0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I1^I0.5^I0.5^I0.5^I0.5^I$
real6$

I would like to replace nreal[2-6]n with ttt' and have tried unsuccessfully the following

sed -i 's/nreal[2-6]n/ttt/g' file

It seems that sed has difficulty to deal with line break. Any idea to fulfill the regex in CentOS?

Much appreciated!

Tags:

2

Answers


  1. 0

    If you want to consider perl then use:

    perl -i -0777 -pe 's/n(?:51[23]real|real[2-6])(?:n|z)/ttt/g' file

    If you want to avoid last reald+ line to be replaced with ttt then use:

    perl -i -0777 -pe 's/n(?:51[23]real|real[2-6])n(?!z)/ttt/g' file

    (?!z) is negative lookahead to fail the match when we have line end just ahead of us.

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  2. 0

    With GNU sed, you need to use the -z option:

    sed -i -z 's/nreal[2-6]n/ttt/g' file
#      ^^

    Now, that you also want to handle specific alternations, you need to enable the POSIX ERE syntax, either with -r or -E option:

    sed -i -Ez 's/n(51[23]real|real[2-6])n/ttt/g' file
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