Shell Programming and Scripting

I need some help. I been doing system admin for the last several years and gotten very rusty on scripting. I need to write a script that will take a log entry and do math using two columns of data to create a new column. I am taking the column(#2) that contains the time and the column(#5) that contains transaction milliseconds and subracting that column for the time column to create a new column in the file. I am butting my head against my screen trying to remember who to do it. Here is an example of my log entry.

20070401 004639826 decode 10578 2770 2.77 00:46:37 29.728125 10.732
17509

So to make it easier to understand if I didn't above(up for about 20 hours working on a project so I might be a little fuzzy, LOL)
I want something that does this:
004639826 - 2770 = 004637056
And overwrites the 004637056 to column 8 to have the following output:
20070401 004639826 decode 10578 2770 2.77 004637056 29.728125 10.732
17509


I much appreciate any help that you can provide.


Thanks in Advance.

Scott

Hi, i am a newer in shell script. Since you have been dba for a long time. I think you should be a expert. But any way, follow is my suggestion:

Code:

awk '{$7=$2-$5
for (i=1;i<NF;i++)
printf("%s",$i)
}' filename

Hope it is useful for you!

$7 should have 2 leading 0's according to requirement

Code:

awk '{$7=$2-$5 
len="%0"length($2)"d"
$7=sprintf(len,$7)
$1=$1
print
}' "file"

output:

Code:

# ./test.sh
20070401 004639826 decode 10578 2770 2.77 004637056 29.728125 10.732 17509

That is what I needed. Thanks Guys. I appreciate your help! I was having a mind freeze. You work with Ciscos, f5s and basic unix for so long you forget the fun stuff. LOL I haven't had to get deep in a long time.

Yeah the column is always going to have 9 characters as it is HHMMSSMMM. I tested it on the log files and with 2 million records worked flawlessly. I appreciate the help greatly.