Hi, I am trying to add line number in front of each line for a file. I tried this : # number each line of a file (number on left, right-aligned) sed = filename | sed 'N; s/^/ /; s/ *\(.\{6,\}\)\n/\1 /' But this command give me line number like bellow: 1 asdasdas 2 sdfsdfsd .... 10 sdfasdf 11 sdfsdf How can make the line number like this: 1010 asdasdas 1020 sdfsdfsd .... 1110 sdfasdf 1120 sdfsdf ... basicly do some math to it:) Thanks in advance

I see no way of solving your problem with sed. It's definitely possible with awk; simply create two variables - one with the starting integer, and the other with the increment. Simply cycle thru the file, printf the beginning integer, and increment the integer by the increment variable printf'ing each line.

$ nl -i10 -v1000 infile.txt Example: $ cat infile.txt 1 2 3 4 5 6 7 8 9 10 11 12 $ nl -i10 -v1000 infile.txt 1000 1 1010 2 1020 3 1030 4 1040 5 1050 6 1060 7 1070 8 1080 9 1090 10 1100 11 1110 12 Luke Chi

Thanks very much Nails and Luke. The Luke's way perfect solved my issue. I did reply a few days ago but for some reason it sidn't posted successfully. Anyway, thanks very much

Glad to hear that Luke Chi

its really excelent Luke. Regards, mallikarjuna setty