Date: Wed, 18 Aug 2010 12:04:32 -0500 (CDT) From: Robert Bonomi <bonomi@mail.r-bonomi.com> To: bugReporter@Haakh.de, jacks@sage-american.com Cc: freebsd-questions@freebsd.org Subject: Re: Extracting a variable listing Message-ID: <201008181704.o7IH4WWL020512@mail.r-bonomi.com>
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> Date: Wed, 18 Aug 2010 17:14:50 +0200
> From: "Dr. A. Haakh" <bugReporter@Haakh.de>
> Subject: Re: Extracting a variable listing
>
> Jack L. Stone schrieb:
> >
> > The content I need will always fall beneath a row of pound signs, and there
> > is content above that row I don't want, like this:
> >
> > bunch of rows I don't need here
> > ############################### <--- the top of stuff needed
> > row1
> > row2
> > row3
> > row4
> > etc, etc....
> >
> awk is your friend .-)
> this script does exactly what you need
> extract.awk
> ---------------
> /^#####+$/ {
> print $0;
> getline;
> print ">>>>>",$0
> while (match($0, "^[[:print:]]+$")) {
> print $0;
> getline;
> }
> }
**GAAACK!!!!**
let awk do the work for you
BEGIN { printing = 0 ; }
printing==1 { print $0 ; }
/^#####+$/ { printing = 1 ; }
usage: awk -f {thatfile} {datafile} >>{masterfile}
The BEGIN line is optional, and the '==1' is also un-necessary, but their
presecee makes the logic clearer for 'somebody else' that looks at it.
One can extract a block of lines from a file with the same logic. just
add a pattern with an action of 'printing=0'.
If the 'printing=1' line is above the 'print $0' line, the start marker
line will be included in the output, if below it won't show.
Similarly, if the 'printing=0' line is _below_ the 'print' line, the end
marker line will be included, if above it, it won't show.
The same basic approach trivially generalizes to extracting multiple blocks
with different start/end markers, or to more complex markers -- e.g. trigger
criteria that involve multiple lines from the source file.
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