Hey all, I'm having an issue with getline I'm hoping someone can help
me with. I have a sample file with lines numbered:

1	Value A
2	Value B
3	Value C
4	Value D
5	Value E
6	etc
7	etc
8	etc
9	etc
10	etc
11	etc
12	etc
13	etc
14	etc
15	Decisive Regex

I'm looking to print ONLY line 1 if line 15 is '/Decisive Regex/'

I tried the awk '/Decisive Regex/{print x};{x=$0}' in a combination of
ways, but I can't get it to go up to line 1

In article <38458941-9b90-4691-a365-95a48826acad@v12g2000vbx.googlegroups.com>,
dsphunxion  <dsphunxion@e-fensive.net> wrote:
>Hey all, I'm having an issue with getline I'm hoping someone can help
>me with. I have a sample file with lines numbered:
>
>1	Value A
>2	Value B
>3	Value C
>4	Value D
>5	Value E
>6	etc
>7	etc
>8	etc
>9	etc
>10	etc
>11	etc
>12	etc
>13	etc
>14	etc
>15	Decisive Regex
>
>I'm looking to print ONLY line 1 if line 15 is '/Decisive Regex/'
>
>I tried the awk '/Decisive Regex/{print x};{x=$0}' in a combination of
>ways, but I can't get it to go up to line 1

The simplest way to approach this sort of problem, as a beginner and
assuming that your file isn't too big (which, nowadays, means less than
a few gigabyes), is to do it like this:

{ A[NR] = $0 }
END	{ Do whatever analysis you want here }

In your case, your END block would be:

END	{ if (A[15] ~ /Decisive Regex/) print A[1] }

-- 
Religion is regarded by the common people as true,
	by the wise as foolish,
	and by the rulers as useful.

(Seneca the Younger, 65 AD)

On Wed, 29 Dec 2010 10:26:39 -0800 (PST)
dsphunxion <dsphunxion@e-fensive.net> wrote:

> Hey all, I'm having an issue with getline I'm hoping someone can help
> me with. I have a sample file with lines numbered:
> 
> 1	Value A
> 2	Value B
> 3	Value C
> 4	Value D
> 5	Value E
> 6	etc
> 7	etc
> 8	etc
> 9	etc
> 10	etc
> 11	etc
> 12	etc
> 13	etc
> 14	etc
> 15	Decisive Regex
> 
> I'm looking to print ONLY line 1 if line 15 is '/Decisive Regex/'
> 
> I tried the awk '/Decisive Regex/{print x};{x=$0}' in a combination of
> ways, but I can't get it to go up to line 1

Not generic, but maybe good enough for this time:

awk 'NR==1{first=$0} NR==15 && /Decisive Regex/{print first;exit}'

On Wed, 29 Dec 2010 19:33:11 +0000 pk <pk@pk.invalid> wrote:

> awk 'NR==1{first=$0} NR==15 && /Decisive Regex/{print first;exit}'

In fact, I seem to understand that you can exit anyway after line 15, so

awk 'NR==1{first=$0} NR==15 {if(/Decisive Regex/)print first;exit}'