Hi,

I need to parse a big CSV file that has some issues

It contains list of users of a network as it follows:

domain\firstname.secondname,number_of_connections_with_that_user,ip_used_to_connect

Example:

college\john.doe,5,192.168.1.1
college\mario.rossi,1,192.168.1.3
college\john.doe,5,192.168.1.2

and so go on...

So as you can see I have John Doe that connected 5 times so I would need an output like this

college\john.doe,5,192.168.1.2,192.168.1.1,....

Can anyone help me?

There are probably many ways of doing this.

I would approach it by first sorting the file by the first field. (man sort... remember to set the -t flag to tell it to use a comma as field separator.) This would place all the "John Does" on consecutive lines.

You could then use an awk script to accumulate a list of IP addresses for identical first field. Only print a line when the first field is different from the previous, again making sure to specify "," as field separator.

This might get you started, sorry that I don't have time to try a sample script as it would be quite involved.

@OP , see here for similar example

Further, the OP is also asking us to "print" the "5" ($2 in awk) only once.

To take further Vrajgh's example
Since the file is now sorted, you need not even accumulate it, but printf without "\n". You

The awk now has the following pseudo code.
BEGIN {a=$1}
{
If $1 != a then ( printf("\n") ; a=$1; printf("%s,%s,",$1,$2) }
printf("%s",$3) ;
}
END {printf("\n"); }

OK

put the $1 outside BEGIN block.

I have real base knowledge as for scripting...I tried to build something starting with sort and the awk but didn't made it. I'm trying to develop my scripting skills...but anyone can help me? My boss is asking for this thing every damn morning...

and? where's your code? its your work remember? not ours.. furthermore , some of use have already shown you ways to do it. now pull up your socks and show us something.

awk -F","
BEGIN {a=}$1
{
If $1 != a then ( printf("\n") ; a=$1; printf("%s,%s,",$1,$2) }
printf("%s",$3) ;
}
END {printf("\n"); }
OFS="," prova1.csv

I'm so lost at this I'm not asking for a solution I'm asking for an explanation that guides me to the solution

don't just follow blindly the pseudocode AnanthaP gives you. Its wrong in syntax. Read the gawk doc (see my sig) to learn how to use awk. Or see here for simpler one.

Sometime people don't have the time to learn awk and need to resolve problems quickly. That's what are forums for also. I don't need you to bring me internet documentation, google does an excellent job at that. I needed directions to build this darn thing by tonight...

Let's drop it, you can go back to you're teaching class...I'll solve my problem another way...

one sentence says it all. you are just too lazy, even with already given hints.