[gentoo-user] Grep question

[gentoo-user] Grep question

[Adam Carter]

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I need to select all the lines between string1 and string2 in a file. String1 exists on an entire line by itself and string2 will be at the start of a line. What's the syntax? I cant use -A as there is a variable number of lines.

Thanks.


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Re: [gentoo-user] Grep question

[Mike Kazantsev]

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On Mon, 2 Mar 2009 13:01:31 +1100
Adam Carter <Adam.Carter@optus.com.au> wrote:

> I need to select all the lines between string1 and string2 in a file. String1 exists on an entire line by itself and string2 will be at the start of a line. What's the syntax? I cant use -A as there is a variable number of lines.

I doubt there's a solution involving grep, unless you use it twice in
the same pipe:
  grep -A9999 string1 /some/file | grep -B 9999 string2

But there can be any amount of more elegant solutions, involving
sed:
  sed -n '/string1/,/string2/p' /some/file

-- 
Mike Kazantsev // fraggod.net

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Re: [gentoo-user] Grep question

[Steven Lembark]

Adam Carter wrote:
> I need to select all the lines between string1 and string2 in a file.
> String1 exists on an entire line by itself and string2 will be at the
> start of a line. What's the syntax? I cant use -A as there is a variable
> number of lines.

Perl will handle this easily enough for you.

Assuming you want to print string1 and string2:

    perl -n -e 'print if /string1/ ../string2/';

The '..' notation behaves sort of like a triac
(flip-flop?): it is false until the first test
is true and true until the second passes, at
which point it stays false again.

for example:

$ cat a
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
foo     <-- /foo/ true here
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
bar     <-- /bar/ true here
fdsa
fdsa
fdsa

$ perl -n -e 'print if /foo/ .. /bar/';
foo
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
bar


-- 
Steven Lembark                                            85-09 90th St.
Workhorse Computing                                 Woodhaven, NY, 11421
lembark@wrkhors.com                                      +1 888 359 3508

[gentoo-user] Re: Grep question

[James]

Adam Carter <Adam.Carter <at> optus.com.au> writes:


> I need to select all 
> the lines between string1 and string2 in a file. String1 exists on 
an entire 
> line by itself and string2 will be at the start of a line. What's 
the syntax? I 
> cant use -A as there is a variable number of lines.

AWK

is my vote. Old, *SIMPLE* and used by most other packages when pattern matching
is involved. Often AWK and SED go together..... As do Perl and AWK


http://www.softpanorama.org/Tools/awk.shtml


hth,

James

[gentoo-user] Re: Grep question

[Harry Putnam]

James <wireless@tampabay.rr.com> writes:

> Adam Carter <Adam.Carter <at> optus.com.au> writes:
>
>
>> I need to select all 
>> the lines between string1 and string2 in a file. String1 exists on 
> an entire 
>> line by itself and string2 will be at the start of a line. What's 
> the syntax? I 
>> cant use -A as there is a variable number of lines.
>
> AWK
>
> is my vote. Old, *SIMPLE* and used by most other packages when
> pattern matching is involved. Often AWK and SED go together..... As
> do Perl and AWK

Yup and using Steves' example:

$ cat a
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
abcd
foo     <-- /foo/ true here
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
bar     <-- /bar/ true here
fdsa
fdsa
fdsa

cat a | awk '/^foo/{FLAG=1}\
             FLAG{print} \
             /^bar/{FLAG=""}'
foo
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
asdf
bar

Re: [gentoo-user] Re: Grep question

[Etaoin Shrdlu]

On Tuesday 3 March 2009, 03:10, Harry Putnam wrote:

> cat a | awk '/^foo/{FLAG=1}\
>              FLAG{print} \
>              /^bar/{FLAG=""}'

awk '/^foo/,/^bar/' a 

does the same :)

[gentoo-user] Re: Grep question

[Harry Putnam]

Etaoin Shrdlu <shrdlu@unlimitedmail.org> writes:

> On Tuesday 3 March 2009, 03:10, Harry Putnam wrote:
>
>> cat a | awk '/^foo/{FLAG=1}\
>>              FLAG{print} \
>>              /^bar/{FLAG=""}'
>
> awk '/^foo/,/^bar/' a 
>
> does the same :)

Nice...

RE: [gentoo-user] Re: Grep question

[Adam Carter]

> > awk '/^foo/,/^bar/' a
> >
> > does the same :)
>
> Nice...

Thanks for all these answers. Interesingly when I moved the sed script (sed "s/;/\\n/g") from Linux to Solaris it failed as Solaris sed doesn't like putting the newline character as the "translated to" bit. Installing GNU sed on the Solaris box sorted that out.

Re: [gentoo-user] Re: Grep question

[Etaoin Shrdlu]

On Friday 6 March 2009, 00:01, Adam Carter wrote:
> > > awk '/^foo/,/^bar/' a
> > >
> > > does the same :)
> >
> > Nice...
>
> Thanks for all these answers. Interesingly when I moved the sed script
> (sed "s/;/\\n/g") from Linux to Solaris it failed as Solaris sed
> doesn't like putting the newline character as the "translated to" bit.
> Installing GNU sed on the Solaris box sorted that out.

Or for the future, with seds that do not like \n in the rhs, you can do

sed 's/;/\
/g'