Suppress the match itself in grep

Suppose I'have lots of files in the form of

First Line Name
Second Line Surname Adress
Thi开发者_StackOverflow社区rd Line etc
etc

Now I'm using grep to match the first line. But I'm doing this actually to find the second line. The second line is not a pattern that can be matched (it's just depend on the first line). My regex pattern works and the command I'm using is

grep -rHIin pattern . -A 1 -m 1

Now the -A option print the line after a match. The -m option stops after 1 match( because there are other line that matches my pattern, but I'm interested just for the first match, anyway...)

This actually works but the output is like that:

./example_file:1:        First Line Name
./example_file-2-        Second Line Surname Adress

I've read the manual but couldn't fidn any clue or info about that. Now here is the question.

How can I suppress the match itself ? The output should be in the form of:

./example_file-2-        Second Line Surname Adress

---

sed to the rescue:

sed -n '2,${p;n;}'

The particular sed command here starts with line 2 of its input and prints every other line. Pipe the output of grep into that and you'll only get the even-numbered lines out of the grep output.

An explanation of the sed command itself:

2,$ - the range of lines from line 2 to the last line of the file

{p;n;} - print the current line, then ignore the next line (this then gets repeated)

(In this special case of all even lines, an alternative way of writing this would be sed -n 'n;p;' since we don't actually need to special-case any leading lines. If you wanted to skip the first 5 lines of the file, this wouldn't be possible, you'd have to use the 6,$ syntax.)

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You can use sed to print the line after each match:

sed -n '/<pattern>/{n;p}' <file>

To get recursion and the file names, you will need something like:

find . -type f -exec sed -n '/<pattern>/{n;s/^/{}:/;p}' \;

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If you have already read a book on grep, you could also read a manual on awk, another common Unix tool.

In awk, your task will be solved with a nice simple code. (As for me, I always have to refresh my knowledge of awk's syntax by going to the manual (info awk) when I want to use it.)

Or, you could come up with a solution combining find (to iterate over your files) and grep (to select the lines) and head/tail (to discard for each individual file the lines you don't want). The complication with find is to be able to work with each file individually, discarding a line per file.

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You could pipe results though grep -v pattern