[SOLVED] awk help printing only if element is new in array

babbab · 01-30-2013, 09:29 PM

so far

I could build array using

Code:

name_list[$3] = 1

adding only 3rd column to name_list
how do I print only if element is new in array?

danielbmartin · 01-30-2013, 09:53 PM

Quote:

Originally Posted by babbab

how do I print only if element is new in array?

What characteristic distinguishes New from Old?

Daniel B. Martin

babbab · 01-30-2013, 10:02 PM

say data is..

Code:

aaa 123
bbb 456
bbb 789
ccc 101112
ccc 131415
....

so

Code:

name_list[$1] = 1

now array contains
namelist["aaa"] = 1
namelist["bbb"] = 1
namelist["ccc"] = 1

my intention is to print out only non-duplicated at certain column records.
it should only print out first 1st column encountered data

so desired output is..

Code:

aaa 123
bbb 456
ccc 101112

babbab · 01-30-2013, 10:17 PM

hmmm

this code actually worked for that matter

Code:

if (name_list[$3] == 0){
    #print code
}
name_list[$3] = 1

thanks for reading my post!!!

grail · 01-31-2013, 06:44 AM

Using your example:

Code:

awk '!_[$1]++' file

David the H. · 01-31-2013, 04:17 PM

And in case you're wondering how grail's line works, it's basically entry #43 here:

http://www.catonmat.net/blog/awk-one...ined-part-two/