Shell Programming and Scripting

How can i awk/sed to print the last line of an recurring pattern on the 3rd field?

Input lines:

Code:

123456.1 12 1357911 11111.1 01
123456.2 12 1357911 11111.2 02
123456.3 12 1357911 11111.3 03
123456.4 12 1357911 11111.4 04
123456.5 12 1357911 11111.5 05
246810.1 12 1357911 22222.1 01
246810.2 12 1357911 22222.2 02
246810.3 12 1357911 22222.3 03
789101.1 12 1357911 33333.1 01
789101.2 12 1357911 33333.2 02
789101.3 12 1357911 33333.3 03
789101.4 12 1357911 33333.4 04
789101.5 12 1357911 33333.5 05

Desired output:

Code:

123456.5 12 1357911 11111.5 05
246810.3 12 1357911 22222.3 03
789101.5 12 1357911 33333.5 05

Please assist and thanking you in advance.

---------- Post updated at 04:29 PM ---------- Previous update was at 04:19 PM ----------

i think i found the answer on this link - change to $3 instead of $1
https://www.unix.com/shell-programmin...eld-match.html

.. test in progress..

By third field, you mean the 1's, 2's and 3's but not the fraction, apparently. Do we need to preserve order of groups? Are they always in the right order? For instance, sort -u preserves the first for any key value, so you can reverse the lines (tail -r) and key sort on "the third field", but it will re-sort by the third field. Well, probably harder in sed, using regex to find fields:

Code:

sed '
  :loop
  $b
  N
  s/^[^.]*\.[^.]* \([^.]*\)\..*\n\([^.]*\.[^.]* \1\..*\)/\2/
  t loop
  P
  s/.*\n//
  t loop
 '

Narrative: Set a branch target named loop, if at EOF branch to end (print and exit), get the next line, if the key fields are the same discard the first line and go to loop, print the first line, discard it and branch to loop. This regex keys on '.' mostly, ' ' occasionally, exploiting your data structure to avoid a lot of repeated regex patterns to count fields.

test completed and working as expected per mod below:

Code:

awk '$3 != prevIDX && FNR != 1 { print prev } { prevIDX=$3; prev=$0 } END { print prev }'

Code:

 awk -F"." '{u[$1]=$0}END{for(i in u) print u[i]}'

Where did you say $0 was the key or . the delimiter??