Shell Programming and Scripting

hii i have a huge amt of data stored in a file.Here in this file i need to remove duplicates rows in such a way that the last column has different data & i must check for greatest among last colmn data & print the largest data along with other entries but just one of other duplicate entries is needed .For example the given file which looks like this
1902 8 22 3 40.0000 77.0000 8.60
1902 8 22 3 40.0000 76.5000 8.20
1902 8 22 3 40.0000 76.5000 8.30
1902 8 22 3 40.0000 77.0000 8.40
1902 8 22 3 39.8000 76.2000 8.10
1902 9 30 6 38.5000 67.0000 7.70
1902 9 30 6 38.5000 67.0000 6.30
1902 10 6 9 36.5000 70.5000 7.20
1902 12 4 22 37.8000 65.5000 4.90

Now i want the output for such a file as below
1902 8 22 3 40.0000 77.0000 8.60
1902 8 22 3 40.0000 76.5000 8.30
1902 8 22 3 39.8000 76.2000 8.10
1902 9 30 6 36.5000 67.0000 7.70
1902 10 6 9 36.5000 70.5000 7.20
1902 12 4 22 37.8000 65.5000 4.90
------

Why the o/p have

Code:

1902  8 22  3  40.0000  76.5000 8.20

instead of

Code:

1902  8 22  3  40.0000  76.5000 8.30

although Your condition ( last column value > previous value for the same data ).

oh sorry by mistak i wil correct my output a min...

---------- Post updated at 04:18 AM ---------- Previous update was at 04:16 AM ----------

ok now tell me how ....

something like this :

Code:

awk '{ va=$NF;$NF=" "; if ($0 in a) { if (va > a[$0]){a[$0]=va}} else {a[$0]=va}} END { for ( i in a ) print i" "a[i] }'  file_name.txt

need to check further as the order of the elements in associative array is not the same.

thanks a lot its working.but first few lines are been deleted in my file...

one more thing for the same data if i need the ouput as

1902 8 22 3 40.0000 77.0000 8.60
1902 9 30 6 38.5000 67.0000 7.70
1902 10 6 9 36.5000 70.5000 7.20
1902 12 4 22 37.8000 65.5000 4.90

that is just check for first 4 columns if its equal & other columns for largest value as shown in above ..

Something like this :

Code:

awk '{ va2=$NF;va1=$(NF-1);va=$(NF-2);$NF=" ";$(NF-1)=" ";$(NF-2)=" ";if ($0 in a) { if (va" "va1" "va2 >a[$0] ){a[$0]=va" "v
a1" "va2" "}} else {a[$0]=va" "va1" "va2}} END { for ( i in a ) print i" "a[i] }'  file_name.txt

As i said already :

need to check further as the order of the elements in associative array is not the same.

Another way...

For the 1st one...

Code:

 
sort -n +6 infile | awk '{t[$1" "$2" "$3" "$4" "$5" "$6]=$7}END{for (i in t){print i,t[i]}}'

For the 2nd one...

Code:

 
sort -n +4 infile | awk '{t[$1" "$2" "$3" "$4]=$5" "$6" "$7}END{for (i in t){print i,t[i]}}'