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Consider the input:
=sec1= some-line some-other-line foo bar=baz =sec2= c=baz If I wish to process only =sec1= I can for example comment out the section by:
sed -e '/=sec1=/,/=[a-z]*=/s:^:#:' < input ... well, almost.
This will comment the lines including "=sec1=" and "=sec2=" lines, and the result will be something like:
#=sec1= #some-line #some-other-line # #foo #bar=baz # #=sec2= c=baz My question is: What is the easiest way to exclude the start and end lines from a /START/,/END/ range in sed?
I know that for many cases refinement of the "s:::" claws can give solution in this specific case, but I am after the generic solution here.
In "Sed - An Introduction and Tutorial" Bruce Barnett writes: "I will show you later how to restrict a command up to, but not including the line containing the specified pattern.", but I was not able to find where he actually show this.
In the "USEFUL ONE-LINE SCRIPTS FOR SED" Compiled by Eric Pement, I could find only the inclusive example:
# print section of file between two regular expressions (inclusive) sed -n '/Iowa/,/Montana/p' # case sensitive 
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1d deletes the first line ( 1 to only act on the first line, d to delete it) $d deletes the last line ( $ to only act on the last line, d to delete it)
sed -i '$ d' filename . The -i flag edits file in place. This deletes the last line. To delete the first line, use sed -i '1,1d' filename .
The first line of a file can be skipped by using various Linux commands. As shown in this tutorial, there are different ways to skip the first line of a file by using the `awk` command. Noteably, the NR variable of the `awk` command can be used to skip the first line of any file.
Using `sed` to replace \n with a comma By default, every line ends with \n when creating a file. The `sed` command can easily split on \n and replace the newline with any character. Another delimiter can be used in place of \n, but only when GNU sed is used.
This should do the trick:
sed -e '/=sec1=/,/=sec2=/ { /=sec1=/b; /=sec2=/b; s/^/#/ }' < input This matches between sec1 and sec2 inclusively and then just skips the first and last line with the b command. This leaves the desired lines between sec1 and sec2 (exclusive), and the s command adds the comment sign.
Unfortunately, you do need to repeat the regexps for matching the delimiters. As far as I know there's no better way to do this. At least you can keep the regexps clean, even though they're used twice.
This is adapted from the SED FAQ: How do I address all the lines between RE1 and RE2, excluding the lines themselves?
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If you're not interested in lines outside of the range, but just want the non-inclusive variant of the Iowa/Montana example from the question (which is what brought me here), you can write the "except for the first and last matching lines" clause easily enough with a second sed:
sed -n '/PATTERN1/,/PATTERN2/p' < input | sed '1d;$d'
Personally, I find this slightly clearer (albeit slower on large files) than the equivalent
sed -n '1,/PATTERN1/d;/PATTERN2/q;p' < input
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