Can any one give me command How to delete duplicate records with out sort.

Suppose if the records like below:

345,bcd,789
123,abc,456
234,abc,456
712,bcd,789

out tput should be
345,bcd,789
123,abc,456

Key for the records is 2nd and 3rd fields.fields are seperated by colon(,).

Try:

awk '!($2$3 in a){a[$2$3]++;print}' FS=',' file

for i in `cat filename | cut -d "," -f2 | uniq`
do
sed -n '/'${i}'/{p;q;}' filename
done

Or:

awk '!x[$2,$3]++' FS="," file

you can use 'uniq' command also to remove the duplicate records which is ver easy to use. Check out the man pages of this command

You need a sorted input for uniq ....

awk '!x[$2,$3]++' FS="," file

This has been a true grit work horse one liner.

I have use it extensively.

Does anyone know if it can be instructed to work within a range of values?
I suspect it wouldn't be a one liner.

For example:

My file contents are all numbers (a mixture of intergers and floating point), where field one is a unique point number, field two is an X or Easting coordinate, field 3 is a Y or Northing coordinate, and field four is an elevation:

1,2.1,3.1,1.1
2,2.2,3.2,2.2
3,2.3,3.3,3.3
4,3.4,3.4,4.4
5,3.5,3.5,5.5
6,3.6,3.6,6.6
7,4.7,4.7,7.1
8,4.8,4.8,8.8
9,4.9,4.9,9.9

I would like to process the file via fields two and three and have the result be:

1,2.1,3.1,1.1
3,2.3,3.3,3.3
4,3.4,3.4,4.4
6,3.6,3.6,6.6
7,4.7,4.7,7.1
9,4.9,4.9,9.9

So I think what I am asking is, that field 2 and 3 be considered duplicates if they are in the range "$2-0.1 to $2+0.1" and "$3-0.1 to $3+0.1".
That's the best way I have of decribing it.

Thanks in advance,
Kenny.