[9fans] sort strangeness

[9fans] sort strangeness

[Gregory Pavelcak]

Just noticed this

cpu% cat tmp/sorttest
2
7
2.1
2.1.4
2.1.1
cpu% sort tmp/sorttest
2
2.1
2.1.1
2.1.4
7
cpu% sort -u tmp/sorttest
2
2.1
2.1.1
2.1.4
7
cpu% sort -n tmp/sorttest
2
2.1
2.1.4
2.1.1
7
cpu% sort -n -u tmp/sorttest
2
2.1
7
cpu%


Greg

Re: [9fans] sort strangeness

[Tharaneedharan Vilwanathan]

hi,

doesnt it seem to be fine?

> Just noticed this
>
> cpu% cat tmp/sorttest
> 2
> 7
> 2.1
> 2.1.4
> 2.1.1
> cpu% sort tmp/sorttest
> 2
> 2.1
> 2.1.1
> 2.1.4
> 7
------> sorts the string values
> cpu% sort -u tmp/sorttest
> 2
> 2.1
> 2.1.1
> 2.1.4
> 7
------> sorts the string values and removes any duplicates (none here)
> cpu% sort -n tmp/sorttest
> 2
> 2.1
> 2.1.4
> 2.1.1
> 7
-----> sorts the numeric values (which is an integer or floating-point
value of format x.y)
In this case 2.1.4 is treated as 2.1 (ignores second "." and following
characters)

> cpu% sort -n -u tmp/sorttest
> 2
> 2.1
> 7
----> sorts the numeric values (which is an integer or floating-point
value of format x.y)
and removes any duplicates. In this case, 2.1, 2.1.4 and 2.1.1 are all
2.1, so removes
duplicates.

or, am i missing something?

thanks
dharani

Re: [9fans] sort strangeness

[Gregory Pavelcak]

I think you and Richard are right. Looking at the man page,
the behavior is not unexpected. I mis-read what my own
experiment did and thought sort -n actually sorted 2.1.4
and 2.1.1.  I guess it's more of a 4am-on-a-sleepless-night
problem than a sort problem.

Thanks.

Greg

Re: [9fans] sort strangeness

[Richard Miller]

You probably want it to look at the rest of the line after sorting
according to the initial numeric string, like this:

cpu% cat tmp/sorttest
2
7
2.1
2.1.4
2.1.1
term% sort +0n +1 -t. -u tmp/sorttest
2
2.1
2.1.1
2.1.4
7

I think the "strangeness" you observed is consistent with what
the man page says:

          -n   An initial numeric string, consisting of optional white
               space, optional plus or minus sign, and zero or more
               digits with optional decimal point, is sorted by arith-
               metic value.
          -u         Suppress all but one in each set of equal lines.
                     Ignored bytes and bytes outside keys do not par-
                     ticipate in this comparison.