Need help with parser unix script

[yaniv]

Hi all,

I am looking for a unix command/script that would return line i+1
according to String in line i.
I mean, if i found a string XXX in line 3 then return line 4 and so
on.

Any help would be apperciated,
-- Valiky

[Andy Hibbins]

yaniv wrote:

> Hi all,
>
> I am looking for a unix command/script that would return line i+1
> according to String in line i.
> I mean, if i found a string XXX in line 3 then return line 4 and so
> on.

The gnu grep command may be what you need:

grep -A 1 XXX /etc/afilename | grep -v XXX

where XXX is the string to search
and /etc/afilename is the filename to search.

say if /etc/afilename contained the following:

XXXdf
1
XXXfe
2
XXXge
3
XXXht
4

Output of the command would be:

1
2
3
4

[Dave Hinz]

On 16 May 2004 04:28:52 -0700, yaniv <valiky@hotmail.com> wrote:

> Hi all,
>
> I am looking for a unix command/script that would return line i+1
> according to String in line i.
> I mean, if i found a string XXX in line 3 then return line 4 and so
> on.

When is your homework due? What have you tried so far? Show what
you've done & where you're stuck, or describe your approach...something.

[yaniv]

It's not HW...

Basically i am looking to go over /etc/vfstab, which contains lines of
the following form:

# <Description>
/dev/dsk/... /home/bill ....

I want to print the device line in case i found a special string in
the description line right above.

So far I've tried:
1) sed
sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h
But i couldn't get rid of the description line in the output

2) grep -A1
but in case multiple lines matched, it returns the devices lines
seperated with --, which is quite annoying

help please...

tnx,
valiky

[Chris F.A. Johnson]

On 2004-05-16, yaniv wrote:

> It's not HW...
>
> Basically i am looking to go over /etc/vfstab, which contains lines of
> the following form:
>
> # <Description>
> /dev/dsk/... /home/bill ....
>
> I want to print the device line in case i found a special string in
> the description line right above.
>
> So far I've tried:
> 1) sed
> sed -n -e '/regexp/{=;x;1!p;g;$!N;p;D;}' -e h
> But i couldn't get rid of the description line in the output

sed -n '/regexp/{n;p;}'

> 2) grep -A1
> but in case multiple lines matched, it returns the devices lines
> seperated with --, which is quite annoying

--
Chris F.A. Johnson [url]http://cfaj.freeshell.org/shell[/url]
================================================== =================
My code (if any) in this post is copyright 2004, Chris F.A. Johnson
and may be copied under the terms of the GNU General Public License

[Rovall]

Andy Hibbins wrote:

> yaniv wrote:
>

>> Hi all,
>>
>> I am looking for a unix command/script that would return line i+1
>> according to String in line i.
>> I mean, if i found a string XXX in line 3 then return line 4 and so
>> on.

>
> The gnu grep command may be what you need:
>
> grep -A 1 XXX /etc/afilename | grep -v XXX
>
> where XXX is the string to search
> and /etc/afilename is the filename to search.
>
> say if /etc/afilename contained the following:
>
> XXXdf
> 1
> XXXfe
> 2
> XXXge
> 3
> XXXht
> 4
>
> Output of the command would be:
>
> 1
> 2
> 3
> 4

Not exactly. If you have a text like:

# bill's homedir
/dev/dsk/... /home/bill ....

and then do

grep -A 1 bill /etc/afilename | grep -v bill

you'll have null output!

For this case (searching through comments), I'd suppose to use something
like this:

grep -A 1 XXX <file> | grep -v '^#' | grep -v '^--$'

Second grep to filter out comments, third to avoid -- lines.

[James T. Dennis]

yaniv <valiky@hotmail.com> wrote:

> Hi all,

> I am looking for a unix command/script that would return line i+1
> according to String in line i.
> I mean, if i found a string XXX in line 3 then return line 4 and so
> on.

> Any help would be apperciated,
> -- Valiky

#!/bin/sh
while read line; do
case "$line" in
*XXX*) read line; echo "$line";;
esac
done

Just call that in a pipeline or with input redirection. This one just
uses shell built-ins and should work for any Bourne compatible shell. It
shouldn't need any bash or Korn extensions.




--
Jim Dennis,
Starshine: Signed, Sealed, Delivered

[John W. Krahn]

yaniv wrote:

>
> I am looking for a unix command/script that would return line i+1
> according to String in line i.
> I mean, if i found a string XXX in line 3 then return line 4 and so
> on.

perl -ne'/XXX/&&print scalar<>' yourfile


John
--
use Perl;
program
fulfillment