AWK - Column width

Author

Column width

Link King

2004-03-19, 8:23 pm

Hi folks.

Quick question I'm sure someone can answer easily for me. I'm using awk
to format several reports I run daily. Each report has numerous columns
and the width of each column is currently fixed. However, I'd like to be
able to adjust column width based on the largest value in each of the
columns. Is there a way to do that?

Thanks in advance!

--
Link King
king@kinger.net

Robert Peirce

2004-03-19, 8:23 pm

In article <Pine.LNX.4.44.0402041603430.27086-100000@mogul.kinger.net>,
Link King <king@kinger.net> wrote:

> Hi folks.
>
> Quick question I'm sure someone can answer easily for me. I'm using awk
> to format several reports I run daily. Each report has numerous columns
> and the width of each column is currently fixed. However, I'd like to be
> able to adjust column width based on the largest value in each of the
> columns. Is there a way to do that?

Sure. However, you pretty much have to scan the file twice. First you
have to determine the widest columns. Then you have to feed that info
to the report generator. Depending on the size of the report, you might
be able to load it into an array rather than scan it, but I can't think
of any way to determine the widest columns without looking at the whole
file first and then printing it.

--
Robert B. Peirce, Venetia, PA 724-941-6883
bob AT peirce-family.com [Mac]
rbp AT cooksonpeirce.com [Office]

Doug McClure

2004-03-19, 8:23 pm

Here should be enough information to get you started. It's a
one-column, untested sample.

{
if (length($1) > max_width} max_width = length($1)
x[NR] = $1
}

END {
fmt = "%" max_width "d\n" # So fmt = "%12d\n" or whatever

for (i = 1; i <= NR; i++) printf(fmt, x[i])
}

If you use GAWK and perhaps some other AWK's, you can replace my
printf statement with

printf("%*d\n", max_width, x[i])

***

As someone else mentioned, you might have to read the file twice if
you can't store everything in an array. But it's possible that
although you have a huge input file, maybe you don't print but a
fraction of the file. In that case, an array might work fine.

***

Also, I just realized that if you don't have to use the minimum
maximum field length, you can just use a large field width that you
are certain could work. So my printf would then become

printf("%20d\n", x[i])

DKM

On Wed, 4 Feb 2004 16:06:07 -0700, Link King <king@kinger.net> wrote:

>
>Hi folks.
>
>Quick question I'm sure someone can answer easily for me. I'm using awk
>to format several reports I run daily. Each report has numerous columns
>and the width of each column is currently fixed. However, I'd like to be
>able to adjust column width based on the largest value in each of the
>columns. Is there a way to do that?
>
>Thanks in advance!

To contact me directly, send EMAIL to (single letters all)
DEE_KAY_EMM AT EarthLink.net

Patrick TJ McPhee

2004-03-19, 8:23 pm

In article <Pine.LNX.4.44.0402041603430.27086-100000@mogul.kinger.net>,
Link King <king@kinger.net> wrote:

% Quick question I'm sure someone can answer easily for me. I'm using awk
% to format several reports I run daily.

This is not what you're asking, but consider using troff and tbl to do
this. Your awk program spits out a load of gibberish like this

.TS H
c c c
l l n

Link King

2004-03-19, 8:23 pm

Worked like a charm. The reports are generally chopped at about 100 rows
per so reading the file twice isn't a huge issue. Thanks for the pointer!

-Link

> Here should be enough information to get you started. It's a
> one-column, untested sample.
>
> {
> if (length($1) > max_width} max_width = length($1)
> x[NR] = $1
> }
>
> END {
> fmt = "%" max_width "d\n" # So fmt = "%12d\n" or whatever
>
> for (i = 1; i <= NR; i++) printf(fmt, x[i])
> }
>
> If you use GAWK and perhaps some other AWK's, you can replace my
> printf statement with
>
> printf("%*d\n", max_width, x[i])
>
> ***
>
> As someone else mentioned, you might have to read the file twice if
> you can't store everything in an array. But it's possible that
> although you have a huge input file, maybe you don't print but a
> fraction of the file. In that case, an array might work fine.
>
> ***
>
> Also, I just realized that if you don't have to use the minimum
> maximum field length, you can just use a large field width that you
> are certain could work. So my printf would then become
>
> printf("%20d\n", x[i])
>
> DKM
>
>
> On Wed, 4 Feb 2004 16:06:07 -0700, Link King <king@kinger.net> wrote:
>
>
>
> To contact me directly, send EMAIL to (single letters all)
> DEE_KAY_EMM AT EarthLink.net
>

--
Link King
king@kinger.net

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