AWK - locate strings --newbies need hand

Author

locate strings --newbies need hand

linuxnb@gmail.com

2006-10-30, 7:01 pm

Hi, Dear awk gurus,

I have a problem to use awk to clarify the exact string in a file,

for instance, the file looks like:

abc bcd cdf bcv thr
wbc bsd dgfs cdf bdv thuy

ok, in the 2 lines file, I need print the result:

bcv
bdv

I try to use substr( ), but have no luck, I am new to awk.newbies

So I need your any tips, thanks a lot,

Zhou

Kenny McCormack

2006-10-30, 7:01 pm

In article <1161763217.443506.54910@i42g2000cwa.googlegroups.com>,
linuxnb@gmail.com <linuxnb@gmail.com> wrote:
>Hi, Dear awk gurus,
>
>I have a problem to use awk to clarify the exact string in a file,
>
>for instance, the file looks like:
>
>abc bcd cdf bcv thr
>wbc bsd dgfs cdf bdv thuy
>
>ok, in the 2 lines file, I need print the result:
>
>bcv
>bdv

I suppose:

{ print $(NR+3) }

Thomas Weidenfeller

2006-10-30, 7:01 pm

linuxnb@gmail.com wrote:
> for instance, the file looks like:
>
> abc bcd cdf bcv thr
> wbc bsd dgfs cdf bdv thuy

That example is not very helpful. Is there any order or structure in the
file? E.g. could it be that you always want the second-last field? That
would be

{ print $(NF-1) }

/Thomas

zhouzhenzj@gmail.com

2006-10-30, 7:01 pm

Thomas Weidenfeller wrote:
> linuxnb@gmail.com wrote:
>
> That example is not very helpful. Is there any order or structure in the
> file? E.g. could it be that you always want the second-last field? That
> would be
>
> { print $(NF-1) }
>
>
> /Thomas

thanks a lot, maybe I didn't give more clear example for this kind
request, if the file looks like:
abc bcd cdf bcv thr
wbc bsd dgfs cdf bdv thuy
ags cdf kjdg jindh lkljh lkjh

then print:
bcv
bdv
kjdg

now the example is more clear that the result will be just after "cdf",
now how to do that?

Thanks a lot,

Zhou

Lorenz

2006-10-30, 7:01 pm

zhouzhenzj@gmail.com wrote:
>thanks a lot, maybe I didn't give more clear example for this kind
>request, if the file looks like:
>abc bcd cdf bcv thr
>wbc bsd dgfs cdf bdv thuy
>ags cdf kjdg jindh lkljh lkjh
>
>then print:
>bcv
>bdv
>kjdg
>
>now the example is more clear that the result will be just after "cdf",
>now how to do that?

gawk "match($0, /cdf +([^ ]+)/, a) {print a[1]}" <input file>

Lorenz

Ed Morton

2006-10-30, 7:01 pm

zhouzhenzj@gmail.com wrote:
> Thomas Weidenfeller wrote:
>
>
>
> thanks a lot, maybe I didn't give more clear example for this kind
> request, if the file looks like:
> abc bcd cdf bcv thr
> wbc bsd dgfs cdf bdv thuy
> ags cdf kjdg jindh lkljh lkjh
>
> then print:
> bcv
> bdv
> kjdg
>
> now the example is more clear that the result will be just after "cdf",
> now how to do that?

Depending on your requirements for what to do if/when cdf is the last
field, this might work for you:

awk '{for (i=1;i<NF;i++) if ($i == "cdf") print $(i+1)}' file

Ed.

Kenny McCormack

2006-10-30, 7:01 pm

In article <kgjuj2t0hgdnajf30mutdranki5jcmj6v2@4ax.com>,
Lorenz <lorenznl@yahoo.com> wrote:
>zhouzhenzj@gmail.com wrote:
>
>gawk "match($0, /cdf +([^ ]+)/, a) {print a[1]}" <input file>

That's cute. I had forgotten about GAWK having that match() extension.
Here's a somewhat more straightforward approach (same general theme):

{split(substr($0,index($0," cdf ")),a);print a[2]}

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