Sort and print in line - awk

Question

Input:
54578787 -58 1
6578999 -658- 3
1352413 -541- 11
4564564 -23- 11
654564 -65- 3
6543564 -65- 1
Desired output:
column3 = 1,3,11
Using:
a=$(awk '{print $3}' text | sort -u | paste -s -d,) && paste <(echo "column3 =") <(echo $a)
I only get:
column3 = [large blank] 1,11,3
Other issue: If I remove all hyphens on the second column, I get
column3 = [large blank] ,1,11,3
I think it's a paste command issue.
Last but not least: why do I have 1,11,3 instead of 1,3,11?

Answer 1

I would just use awk:
$ awk '{a[$3]} END {printf "column3 = "; for (i in a) {printf "%d%s", i, (++v==length(a)?"\n":",")}}' file
column3 = 1,3,11
Explanation
a[$3] populate the a[] array with the 3rd column. This way, any new value will create a new index.
END {} perform commands after processing the whole file.
printf "column3 = " prints "column3 =".
for (i in a) {printf "%d%s", i, (++v==length(a)?"\n":",")} loop through the stored values and print them comma separated, unless it is the last one.
Your current solution would work like this:
$ paste -d" " <(echo "column3 =") <(awk '{print $3}' file | sort -u | paste -s -d,)
column3 = 1,11,3
Note there is no need to store in $a. And to have just one space, use paste -d" ".
And to have it sorted numerically? Just add -n to your sort:
$ paste -d" " <(echo "column3 =") <(awk '{print $3}' file | sort -nu | paste -s -d,)
column3 = 1,3,11
With this command you get the same output, no matter the hyphens.

Answer 2

You can do something like
echo "column3 = $(awk '{print $3}' test.txt |sort -nu | paste -s -d, )"
gives me
column3 = 1,3,11
One key element is to sort with the -n option to do numerical sorting.
It also works with the hyphens deleted:
echo "column3 = $(tr -d - < test.txt| awk '{print $3}' |sort -nu | paste -s -d, )"
also outputs
column3 = 1,3,11

Answer 3

If perl is acceptable:
perl -lanE '
$c3{$F[2]} = 1;
END {say "column3 = ", join(",", sort {$a <=> $b} keys %c3)}
' file

Answer 4

my gawk line looks like:
awk '{a[$3]} END{c=asorti(a,d,"#val_num_asc"); printf "column3 = ";
for(x=1;x<=c;x++)printf "%d%s", d[x],(c==x?"\n":",")}' file
output:
column3 = 1,3,11
Note
you need gawk to run that (asorti function)
sorting ascending as numbers
output in single line.

Answer 5

Assuming you truly want the numbers sorted and not just reproduced in the order they are first seen:
$ awk '{print $3}' file | sort -nu | awk '{s=(NR>1?s",":"")$0} END{print "column3 =",s}'
column3 = 1,3,11
You were getting 1,11,3 because without the -n arg for sort you are sorting alphabetically instead of numerically and the first char of 11 (i.e. 1) comes before the first char of 3.