Re: Numerically sorted arguments (in shell)

On 18.06.2024 15:32, Chris Elvidge wrote:

On 14/06/2024 at 08:31, Janis Papanagnou wrote:

I'm using ksh here...
>
I can set the shell parameters in numerical order
>
$ set {1..100}
>
then sort them _lexicographically_
>
$ set -s
>
Or do both in one
>
$ set -s {1..100}
>
I haven't found anything to sort them _numerically_ in shell.
>
What I'm trying to do is iterating over files, say,
   P1.HTM P10.HTM P11.HTM P2.HTM P3.HTM P4.HTM P5.HTM P6.HTM P7.HTM
P8.HTM P9.HTM
in numerical order.
>
Setting the files as shell arguments with P*.HTM will also produce
lexicographical order.
>
The preceding files are just samples. It should work also if the
numbers are non-consecutive (say, 2, 10, 10000, 3333333) so that
iterating using a for-loop and building the list is not an option.
>
(Ideally I'd also like to handle names with two numbers "A35P56.txt"
and irregular string components (lowercase, say, "page310ch1.txt"),
but that's just a nice-to-have. - I might make use of 'sort'?)
>
>
But the primary question is; how to organize/iterate the arguments
*numerically* _in shell_? (If that's possible in some simple way.)
>
>
N.B.: I prefer not to use external commands like 'sort' because of
the negative side effects and bulky code to handle newlines and
blanks in filenames, and messing around with quotes.
>
Janis
>

 
Can you use an array? E.g. (bash, I don't know ksh, but could be similar)

Yes, Ksh supports both, indexed and associative arrays.

 
for i in P1.HTM P10.HTM P11.HTM P2.HTM P3.HTM P4.HTM P5.HTM P6.HTM
P7.HTM P8.HTM P9.HTM; do
j=${i//[![:digit:]]}
files[j]="$i"
done
printf '%s\n' "${files[@]}"
P1.HTM
P2.HTM
P3.HTM
P4.HTM
P5.HTM
P6.HTM
P7.HTM
P8.HTM
P9.HTM
P10.HTM
P11.HTM
 
I'll have to work on names with two (or more?) numbers.

One thing that concerns me with arrays is that I seem to recall that
there was a limit in the number of array elements (which might be an
issue on lengthy lists of files). But some ad hoc tests seem to show
that if there's a limit it's not any more in the 1k/4k elements range
as it had been. (Bolski/Korn says their arrays support at least 4k.)

Janis