Shell Programming and Scripting

Or since 2,3 million lines will have to be deleted, this may be necessary:

Code:

awk 'NR==1{getline x<f}NR==x{print;getline x<f}' f=file file1 > file2

assuming that "file" is sorted numerically. otherwise sort -n first.

@vidyahar85
This statement is ridiculous and has no basis in fact whatsoever.


Back on topic.

My impression is that the O/P is reading "file" and searching through "file1" once for every line in "file" to produce the output in "file2".
Is would appear that "file" contains 700,000 line numbers and that "file1" contains 3,000,000 records.
Therefore the number of reads is:
700,000 times 3,000,000 = 2,100,000,000,000
We are clearly on a powerful computer or it would have got nowhere in two days.

To my mind the issue is how to do ONE PASS through "file1" and select the record numbers contained in "file".
We need the following facts from the O/P.
1) Is "file" in numerical order. Is each record unique? Are there leading zeros in the record numbers. Is there a delimiter?
2) Does the record layout of "file1" include the record number? If so, where exactly in the record? Is there a delimiter?
3) Is there a Database and database language available which would make this task easier?

thx a lot for your replies....
and here is the answer for your questions:
1) Is "file" in numerical order. Is each record unique? NO Are there leading zeros in the record numbers. Is there a delimiter? NO

2) Does the record layout of "file1" include the record number? YES If so, where exactly in the record? Is there a delimiter? they are in one column u can consider enter the delimiter
3) Is there a Database and database language available which would make this task easier? no i'm just trying to reformat it to a specific application.

---------- Post updated at 12:59 AM ---------- Previous update was at 12:58 AM ----------

i will try it and feed u back
thanks a alot

---------- Post updated at 01:01 AM ---------- Previous update was at 12:59 AM ----------

it is just lines
and the sed is used to print a line no.s saved in a file

As suggested in post #6, can we see a sample portion of "file" and "file" making it clear which field is the record number.
Please confirm that "file" can contain duplicate record numbers. If so, this is one that needs cleaning up first.

it didn't work.....syntax error...could you please advise?

---------- Post updated at 08:33 PM ---------- Previous update was at 08:32 PM ----------

it didn't work also...syntax error....could you please explain and advise...i really need your help...

Are you on Solaris? If so use nawk or /usr/xpg4/bin/awk instead of the silly awk that is the default.