06-07-2012
Assuming both files are sorted, maybe you can use "join".
If all the 300 million numbers of file1 start with 372846 (if not, then multiple passes maybe), then you can treat them as integers (minus the prefix). This way you can store them as bitmaps and do look up of the numbers (check prefix first separately) from file2. The first chapter of Jon Bentley's book "programming pearl" talked exactly about this problem.
8 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
Hi
I have the following at the end of a service shutdown script used in part of an active-passive failover setup:
###
# Shutdown all primary Network Interfaces
# associated with failover
###
# get interface names based on IP's
# and shut them down to simulate loss of
# heartbeatd
... (1 Reply)
Discussion started by: mikie
1 Replies
2. UNIX for Advanced & Expert Users
Hi
I am new to Unix/Linux
I know commands and shell scripts which are useful for my project.
But i need to know the basics and commands and shell scripts in detail and easy guide.
Please refer a book.
Thanks
Haripatn (6 Replies)
Discussion started by: haripatn
6 Replies
3. UNIX for Dummies Questions & Answers
I am looking for a file with 'MCR0000000716214' in it. I tried the following command:
grep MCR0000000716214 *
The problem is that the folder I am searching in has over 87000 files and I am getting the following:
bash: /bin/grep: Arg list too long
Is there any command I can use that can... (6 Replies)
Discussion started by: runnerpaul
6 Replies
4. Shell Programming and Scripting
How to find a particular line in a file without using grep? (3 Replies)
Discussion started by: proactiveaditya
3 Replies
5. Shell Programming and Scripting
Hello,
I am processing a text file which contains only words with few combination of characters (it is a dictionary file).
example:
havana
have
haven
haven't
havilland
havoc
Is there a way to exclude only 1 to 8 character long words which not include space or special characters : '-`~.. so... (5 Replies)
Discussion started by: alekkz
5 Replies
6. UNIX for Dummies Questions & Answers
Hi,
We used to use the below commands often.
ps -ef|grep bc
ps -ef|grep abc|grep -v grep
Both fairly returns the same result.
For example, the process name is dynamic and we are having the process name in a variable, how we can apply the above trick.
For example "a" is the... (11 Replies)
Discussion started by: pandeesh
11 Replies
7. Shell Programming and Scripting
Hi All,
We have few scripts where we are using grep -w option to do exact matching of the pattern. This works fine on most of our servers.
But I have encounter a very old HP-UX System(HP-UX B.11.00) where grep -w option is not available.
This is causing my scripts to fail. I need to change... (7 Replies)
Discussion started by: veeresh_15
7 Replies
8. Shell Programming and Scripting
say I have a big list of something like:
sdg2000
weghre10
fewg53
gwg99
jwegwejjwej43
afg10293
I want to remove the numbers of any line that has letters + 1 to 4 numbers
output:
sdg
weghre
fewg
gwg
jwegwejjwej
afg10293 (7 Replies)
Discussion started by: Siwon
7 Replies
COMM(1) User Commands COMM(1)
NAME
comm - compare two sorted files line by line
SYNOPSIS
comm [OPTION]... FILE1 FILE2
DESCRIPTION
Compare sorted files FILE1 and FILE2 line by line.
When FILE1 or FILE2 (not both) is -, read standard input.
With no options, produce three-column output. Column one contains lines unique to FILE1, column two contains lines unique to FILE2, and
column three contains lines common to both files.
-1 suppress column 1 (lines unique to FILE1)
-2 suppress column 2 (lines unique to FILE2)
-3 suppress column 3 (lines that appear in both files)
--check-order
check that the input is correctly sorted, even if all input lines are pairable
--nocheck-order
do not check that the input is correctly sorted
--output-delimiter=STR
separate columns with STR
--total
output a summary
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
Note, comparisons honor the rules specified by 'LC_COLLATE'.
EXAMPLES
comm -12 file1 file2
Print only lines present in both file1 and file2.
comm -3 file1 file2
Print lines in file1 not in file2, and vice versa.
AUTHOR
Written by Richard M. Stallman and David MacKenzie.
REPORTING BUGS
GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Report comm translation bugs to <http://translationproject.org/team/>
COPYRIGHT
Copyright (C) 2017 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
join(1), uniq(1)
Full documentation at: <http://www.gnu.org/software/coreutils/comm>
or available locally via: info '(coreutils) comm invocation'
GNU coreutils 8.28 January 2018 COMM(1)