getting vars from 2 different lines in a file 1

[dendenners]

Hi there,
I'm pretty new to awk and thus my knowledge is fairly patchy. I have a file with a header record (flagged as a header record by the fact that it begins with a "00&quot and a trailer record (begins with an "80&quot and I want to extract the substring from the 15th to the 30th character of the header record to one shell variable, and a similar substring from the trailer record to a different variable. Thanks in advance for any help

 

[grega]

It's not clear as to whether you need to use awk for this. It can be done in the shell quite simply using

VAR1=`grep ^00 filename|cut -c15-30`
VAR2=`grep ^80 filename|cut -c15-30`

If you then need to use those variables in a script be sure to export them.

Greg.

 

[dendenners]

Thank you. That seems to work

 

[bholav]

Could anyone help on "how to compare two fields from two different lines.
For example in the file below,
compare field 13(which is a "1&quot on line 1 with filed 1 of line 4 (which is "2&quot and replace field 13 with the outcome of comparison.

. . . . . . . . . . . . 1 . 1 1 . 1 1 . . . . . . . . . . . . 1 1 . 1 1 . 1 1 .
. . . . . . 1 . 1 1 . 1 1 . 1 1 . 1 1 . 1 1 . 1 2 7 9 9 2 3 2 2 2 2 9 9 9 1 1 1 1 2
1 1 9 2 1 1 1 1 1 1 3 2
8 2 1 9 9 1 1 1 1 1 9 9 9 1 1 9 1 1 1 1