Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Janis Papanagnou <janis_papanagnou+ng@hotmail.com>
Newsgroups: comp.unix.shell
Subject: Re: Numerically sorted arguments (in shell)
Date: Wed, 19 Jun 2024 15:11:27 +0200
Organization: A noiseless patient Spider
Lines: 61
Message-ID: <v4ule0$200am$1@dont-email.me>
References: <v4grk8$2pp51$1@dont-email.me> <v4sena$1eqki$1@dont-email.me>
 <v4ujjt$1vjpg$1@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Injection-Date: Wed, 19 Jun 2024 15:11:28 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="4b708d1a279efe9cda7a957a2de8b2c6";
	logging-data="2097494"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/M2I6q/SZrfffSZTW9pcxS"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.8.0
Cancel-Lock: sha1:/AVcCo+FYLgAFSWXTBTonvA5HtA=
In-Reply-To: <v4ujjt$1vjpg$1@dont-email.me>
Bytes: 3012

On 19.06.2024 14:40, Chris Elvidge wrote:
> On 18/06/2024 at 18:04, Janis Papanagnou wrote:
>> I've just tried a Unix tools based solution (with sed, sort, cut).
>> [...]
>> [...], and for more than two numeric
>> fields it can be modified to dynamically construct the sed pattern,
>> the sort option list, and the cut parameter, once at the beginning;
>> that way we could have a tool for arbitrary amounts of numeric keys in
>> the file name.
>>
>> Note: this program doesn't handle pathological filenames (newlines).
>>
>
> If you're happy not handling pathological filenames:

Well, typically I can indeed ignore them. But it's better of course
to avoid situations where processing is compromised by such names.

> 
> for (( i=1; i<=50; i++ )); do for (( j=2; j<=120; j+=3 )); do touch
> "a${i}b${j}c.txt"; done; done
> to create the files.
> 
> exnums() { j="$(sed 's/[^[:digit:]]\+/ /g' <<<"$@")"; printf '%s%s\n'
> "$j" "$@"; }
> function replaces all non-digit sequences with a space, prints digit
> sequence(s) and original input.
> 
> for i in *; do exnums "$i"; done | sort -k1n -k2n -k3n -k4n | awk
> '{print $NF}'
> sort doesn't seem to care how many -k you use, fields separated with space.
> awk prints the last field of the input.
> 
> This "seems" to work with all manner of filenames from PNN.htm (as your
> original sequence) to p323dc45g12.htm, p324dc45g12.htm, p333dc45g12.htm
> Seems to work in ksh, too.

I tried the approach I outlined above... (here just echo'ing the
created parts)...


N=${1:-1}
sed_a="[^0-9]*\([0-9]\+\)[^0-9]*"
sed_r="\1\t"
sort_a="-k1n"
for (( n=2; n<=N; n++ ))
do
    sed_a+="\([0-9]\+\)[^0-9]*"
    sed_r+="\\${n}\t"
    sort_a+=" -k${n}n"
done
cut_a="-f$((N+1))-"

echo "# The following commands would be connected by pipes:"
echo "sed 's/${sed_a}/${sed_r}&/'"
echo "sort -t$'\t' ${sort_a}"
echo "cut ${cut_a}"


Janis