Hi
I want to compare a string at fixed position 10-20 for all the lines starting with 6. if they dont match it should take a copy of a line starting with 1 and insert it before the line starting with 6. How do i this? Please help

Eg

1 test 1 765533 7643743
6 yes 3 5363653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
7 323323 4343434435 545
6 yes 3 5373653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
6 yes 3 5373653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
6 yes 3 5383653 373833
7 323323 4343434435 545
8 4345435435 5454545 55

so the output should be

1 test 1 765533 7643743
6 yes 3 5363653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
7 323323 4343434435 545
1 test 1 765533 7643743
6 yes 3 5373653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
6 yes 3 5373653 373833
7 323323 4343434435 545
8 4345435435 5454545 55
1 test 1 765533 7643743
6 yes 3 5383653 373833
7 323323 4343434435 545
8 4345435435 5454545 55

can you please explain bit more..like what are you searching for and from which to which line nos.... i think i can help you.......

thnx shishir

Given your sample data it seams that $4 will work fine.
Use nawk or /usr/xpg4/bin/awk on Solaris:

awk '/^1 / { s = $0 }
/^6 / && !t[$4]++ {
  c++ && $0 = s RS $0
  }1' infile

perl:

open FH,"<d:/a.txt";
while(<FH>){
	if(m/^1.*/){
		$line=$_;
		print;
		next;
	}
	if(m/^6.*/){
		@t=split;
		if($temp eq ""){
			$temp=$t[3];
			print;
		}
		else{
			if(!($t[3] eq $temp)){
				print $line;
				print $_;
				$temp=$t[3];
			}	
			else{
				print;
			}		
		}
	}
	else{print;}
}

hi
The field is at fixed position 10-20 not the 4th field necessarily. Could you please help

Thanks

But you put in red the positions 9-15, not 10-20!

With 9-15 it should be:

awk '/^1 / { s = $0 }
/^6 / && !t[substr($0,9,7)]++ {
  c++ && $0 = s RS $0
  }1' infile

That works, Thanks very much.